Initial commit

COPYING.txt

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+The TechPack Modpack for Minetest is
+
+Copyright (C) 2017-2018 Joachim Stolberg  
+
+License of source code
+----------------------
+
+This program is free software; you can redistribute and/or
+modify it under the terms of the GNU Lesser General Public License version 2.1 or later
+published by the Free Software Foundation.
+
+This library is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+Library General Public License for more details.
+
+You should have received a copy of the GNU Library General Public
+License along with this library; if not, write to the
+Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
+Boston, MA  02110-1301, USA.
+
+
+License of media (textures, sounds and documentation)
+-----------------------------------------------------
+
+All textures, sounds and documentation files are licensed under the
+Attribution-ShareAlike 3.0 Unported (CC BY-SA 3.0)
+http://creativecommons.org/licenses/by-sa/3.0/

LICENSE.txt

@@ -0,0 +1,502 @@
+                  GNU LESSER GENERAL PUBLIC LICENSE
+                       Version 2.1, February 1999
+
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+  <signature of Ty Coon>, 1 April 1990
+  Ty Coon, President of Vice
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+That's all there is to it!

gravelsieve/README.md

@@ -0,0 +1,33 @@
+# Gravel Sieve Mod
+A Mod for those who do not want to spend half their lives underground...
+
+Inspired from a Minecr**t Video on YT.
+
+This mod simplifies the extraction of ores by the fact that ores can be obtained simply by sieving gravel.
+
+This mod includes three new tools:
+ - a hammer to produce gravel from Cobblestone
+ - two gravel sieves to find ores (a manual sieve and a automatic sieve)
+
+The sieved gravel can be crafted to Compressed Gravel (inspired by Modern Hippie) and "cooked" in the furnace to get Cobblestone again.
+
+Recipe for the Gravel Sieve:
+
+    Wood,  -----------,  Wood
+    Wood,  Steel Ingot,  Wood
+    Wood,  -----------,  Wood
+
+
+Recipe for the Automatic Gravel Sieve:
+
+    Gravel Sieve,  Mese Crystal,  Mese Crystal
+
+
+Recipe for Compressed Gravel:
+
+    Sieved Gravel, Sieved Gravel,
+    Sieved Gravel, Sieved Gravel,
+
+
+## Dependencies
+default, optional moreores and tubelib   

gravelsieve/depends.txt

@@ -0,0 +1,6 @@
+default
+moreblocks?
+tubelib?
+hopper?
+pipeworks?
+

gravelsieve/description.txt

@@ -0,0 +1 @@
+This mod includes a hammer to produce gravel from Cobblestone and a sieve to sift gravel to find ores.

gravelsieve/hammer.lua

@@ -0,0 +1,68 @@
+--[[
+
+	Gravel Sieve Mod
+	================
+
+	v0.01 by JoSt
+	Derived from the work of RealBadAngel, Maciej Kasatkin (screwdriver)
+
+	Copyright (C) 2017 Joachim Stolberg
+	Copyright (C) 2013-2016 RealBadAngel, Maciej Kasatkin
+	Copyright (C) 2013-2016 Various Minetest developers and contributors
+
+	LGPLv2.1+
+	See LICENSE.txt for more information
+
+]]--
+
+
+gravelsieve.disallow = function(pos, node, user, mode, new_param2)
+	return false
+end
+
+gravelsieve.handler = function(itemstack, user, pointed_thing)
+	if pointed_thing.type ~= "node" then
+		return
+	end
+
+	local pos = pointed_thing.under
+
+	if minetest.is_protected(pos, user:get_player_name()) then
+		minetest.record_protection_violation(pos, user:get_player_name())
+		return
+	end
+
+	local node = minetest.get_node(pos)
+	if node.name == "default:cobble" or node.name == "default:mossycobble" 
+			or node.name == "default:desert_cobble" then
+		node.name = "default:gravel"
+		minetest.swap_node(pos, node)
+		minetest.sound_play({
+			name="default_dig_crumbly"},{
+			gain=1,
+			pos=pos,
+			max_hear_distance=6,
+			loop=false})
+	end
+
+	return itemstack
+end
+
+minetest.register_tool("gravelsieve:hammer", {
+	description = "Hammer converts Cobblestone into Gravel",
+	inventory_image = "gravelsieve_hammer.png",
+	on_use = function(itemstack, user, pointed_thing)
+		gravelsieve.handler(itemstack, user, pointed_thing)
+		return itemstack
+	end,
+})
+
+minetest.register_craft({
+	output = "gravelsieve:hammer",
+	recipe = {
+		{"", "default:steel_ingot", ""},
+		{"", "group:stick", "default:steel_ingot"},
+		{"group:stick", "", ""},
+	}
+})
+

gravelsieve/init.lua

@@ -0,0 +1,517 @@
+--[[
+
+	Gravel Sieve Mod
+	================
+
+	v1.07 by JoSt
+	Derived from the work of celeron55, Perttu Ahola  (furnace)
+	Pipeworks support added by FiftySix
+
+	Copyright (C) 2017-2018 Joachim Stolberg
+	Copyright (C) 2011-2016 celeron55, Perttu Ahola <celeron55@gmail.com>
+	Copyright (C) 2011-2016 Various Minetest developers and contributors
+
+	LGPLv2.1+
+	See LICENSE.txt for more information
+
+	History:
+	2017-06-14  v0.01  First version
+	2017-06-15  v0.02  Manually use of the sieve added
+	2017-06-17  v0.03  * Settings bug fixed
+					   * Drop bug fixed
+					   * Compressed Gravel block added (Inspired by Modern Hippie)
+					   * Recipes for Compressed Gravel added
+	2017-06-17  v0.04  * Support for manual and automatic gravel sieve
+					   * Rarity now configurable
+					   * Output is 50% gravel and 50% sieved gravel
+	2017-06-20  v0.05  * Hammer sound bugfix
+	2017-06-24 	v1.00  * Released version w/o any changes
+	2017-07-08  V1.01  * extended for moreores
+	2017-07-09  V1.02  * Cobblestone bugfix (NathanSalapat)
+	                   * ore_probability is now global accessable (bell07)
+	2017-08-29  V1.03  * Fix syntax listring (Jat15) 
+	2017-09-08  V1.04  * Adaption to Tubelib
+	2017-11-03  V1.05  * Adaption to Tubelib v0.06
+	2018-01-01  V1.06  * Hopper support added
+	2018-01-02  V1.07  * changed to registered ores
+	2018-02-09  V1.08  * Pipeworks support added, bugfix for issue #7
+]]--
+
+gravelsieve = {
+}
+
+dofile(minetest.get_modpath("gravelsieve") .. "/hammer.lua")
+
+gravelsieve.ore_rarity = tonumber(minetest.setting_get("gravelsieve_ore_rarity")) or 1
+
+-- Increase the probability over the natural occurrence
+local PROBABILITY_FACTOR = 3
+
+-- Ore probability table  (1/n)
+gravelsieve.ore_probability = {
+}
+
+
+-- Pipeworks support
+local pipeworks_after_dig = nil
+local pipeworks_after_place = function(pos, placer) end
+
+if minetest.get_modpath("pipeworks") and pipeworks ~= nil then
+	pipeworks_after_dig = pipeworks.after_dig
+	pipeworks_after_place = pipeworks.after_place
+end
+
+-- collect all registered ores and calculate the probability
+local function add_ores()
+	for _,item in  pairs(minetest.registered_ores) do
+		if minetest.registered_nodes[item.ore] then
+			local drop = minetest.registered_nodes[item.ore].drop
+			if type(drop) == "string"
+			and drop ~= item.ore
+			and drop ~= ""
+			and item.ore_type == "scatter"
+			and item.clust_scarcity ~= nil and item.clust_scarcity > 0 
+			and item.clust_size ~= nil and item.clust_size > 0 then
+				local probability = item.clust_scarcity / item.clust_size / 
+								PROBABILITY_FACTOR * gravelsieve.ore_rarity
+				probability = math.floor(probability)
+				if probability > 20 then
+					if gravelsieve.ore_probability[drop] == nil then
+						gravelsieve.ore_probability[drop] = probability
+					else
+						gravelsieve.ore_probability[drop] = 
+										math.min(gravelsieve.ore_probability[drop], probability)
+					end
+				end
+			end
+		end
+	end
+	local overall_probability = 0.0
+	for name,probability in pairs(gravelsieve.ore_probability) do
+		print(string.format("[gravelsieve] %-32s %u", name, probability))
+		overall_probability = overall_probability + 1.0/probability
+	end
+	print(string.format("[gravelsieve] Overall probability %g", overall_probability))
+end	
+
+minetest.after(1, add_ores)
+
+local sieve_formspec =
+	"size[8,8]"..
+	default.gui_bg..
+	default.gui_bg_img..
+	default.gui_slots..
+	"list[context;src;1,1.5;1,1;]"..
+	"image[3,1.5;1,1;gui_furnace_arrow_bg.png^[transformR270]"..
+	"list[context;dst;4,0;4,4;]"..
+	"list[current_player;main;0,4.2;8,4;]"..
+	"listring[context;dst]"..
+	"listring[current_player;main]"..
+	"listring[context;src]"..
+	"listring[current_player;main]"
+
+
+local function allow_metadata_inventory_put(pos, listname, index, stack, player)
+	if minetest.is_protected(pos, player:get_player_name()) then
+		return 0
+	end
+	local meta = minetest.get_meta(pos)
+	local inv = meta:get_inventory()
+	if listname == "src" then
+		return stack:get_count()
+	elseif listname == "dst" then
+		return 0
+	end
+end
+
+local function allow_metadata_inventory_move(pos, from_list, from_index, to_list, to_index, count, player)
+	local meta = minetest.get_meta(pos)
+	local inv = meta:get_inventory()
+	local stack = inv:get_stack(from_list, from_index)
+	return allow_metadata_inventory_put(pos, to_list, to_index, stack, player)
+end
+
+local function allow_metadata_inventory_take(pos, listname, index, stack, player)
+	if minetest.is_protected(pos, player:get_player_name()) then
+		return 0
+	end
+	return stack:get_count()
+end
+
+-- handle the sieve animation
+local function swap_node(pos, meta, start)
+	local node = minetest.get_node(pos)
+	local idx = meta:get_int("idx")
+	if start then
+		if idx == 3 then
+			idx = 0
+		end
+	else
+		idx = (idx + 1) % 4
+	end
+	meta:set_int("idx", idx)
+	node.name = meta:get_string("node_name")..idx
+	minetest.swap_node(pos, node)
+	return idx == 3
+end
+
+-- place ores to dst according to the calculated probability
+local function random_ore(inv, src)
+	local num
+	for ore, probability in pairs(gravelsieve.ore_probability) do
+		if math.random(probability) == 1 then
+			local item = ItemStack(ore)
+			if inv:room_for_item("dst", item) then
+				inv:add_item("dst", item)
+				return true     -- ore placed
+			end
+		end
+	end
+	return false    -- gravel has to be moved
+end
+
+
+local function add_gravel_to_dst(meta, inv)
+	-- maintain a counter for gravel kind selection
+	local gravel_cnt = meta:get_int("gravel_cnt") + 1
+	meta:set_int("gravel_cnt", gravel_cnt)
+
+	if (gravel_cnt % 2) == 0 then  -- gravel or sieved gravel?
+		inv:add_item("dst", ItemStack("default:gravel"))        -- add to dest
+	else
+		inv:add_item("dst", ItemStack("gravelsieve:sieved_gravel")) -- add to dest
+	end
+end
+
+
+-- move gravel and ores to dst
+local function move_src2dst(meta, pos, inv, src, dst)
+	if inv:room_for_item("dst", dst) and inv:contains_item("src", src) then
+		local res = swap_node(pos, meta, false)
+		if res then                                     -- time to move one item?
+			if src:get_name() == "default:gravel" then  -- will we find ore?
+				if not random_ore(inv, src) then        -- no ore found?
+					add_gravel_to_dst(meta, inv)
+				end
+			else
+				inv:add_item("dst", ItemStack("gravelsieve:sieved_gravel")) -- add to dest
+			end
+			inv:remove_item("src", src)
+		end
+		return true  -- process finished
+	end
+	return false -- process still running
+end
+
+-- timer callback, alternatively called by on_punch
+local function sieve_node_timer(pos, elapsed)
+	local meta = minetest.get_meta(pos)
+	local inv = meta:get_inventory()
+	local gravel = ItemStack("default:gravel")
+	local gravel_sieved = ItemStack("gravelsieve:sieved_gravel")
+
+	if move_src2dst(meta, pos, inv, gravel) then
+		return true
+	elseif move_src2dst(meta, pos, inv, gravel_sieved) then
+		return true
+	else
+		minetest.get_node_timer(pos):stop()
+		return false
+	end
+end
+
+
+for automatic = 0,1 do
+for idx = 0,4 do
+	local nodebox_data = {
+		{ -8/16, -8/16, -8/16,   8/16, 4/16, -6/16 },
+		{ -8/16, -8/16,  6/16,   8/16, 4/16,  8/16 },
+		{ -8/16, -8/16, -8/16,  -6/16, 4/16,  8/16 },
+		{  6/16, -8/16, -8/16,   8/16, 4/16,  8/16 },
+		{ -6/16, -2/16, -6/16,  6/16, 8/16, 6/16 },
+	}
+	nodebox_data[5][5] =    (8 - 2*idx) / 16
+
+	local node_name
+	local description
+	local tiles_data
+	local tube_info
+	if automatic == 0 then
+		node_name = "gravelsieve:sieve"
+		description = "Gravel Sieve"
+		tiles_data = {
+			-- up, down, right, left, back, front
+			"gravelsieve_gravel.png",
+			"gravelsieve_gravel.png",
+			"gravelsieve_sieve.png",
+			"gravelsieve_sieve.png",
+			"gravelsieve_sieve.png",
+			"gravelsieve_sieve.png",
+		}
+	else
+		node_name = "gravelsieve:auto_sieve"
+		description = "Automatic Gravel Sieve"
+		tiles_data = {
+			-- up, down, right, left, back, front
+			"gravelsieve_gravel.png",
+			"gravelsieve_gravel.png",
+			"gravelsieve_auto_sieve.png",
+			"gravelsieve_auto_sieve.png",
+			"gravelsieve_auto_sieve.png",
+			"gravelsieve_auto_sieve.png",
+		}
+		
+		-- Pipeworks support
+		tube_info = {
+			insert_object = function(pos, node, stack, direction)
+				local meta = minetest.get_meta(pos)
+				local inv = meta:get_inventory()
+				if automatic == 0 then
+					local meta = minetest.get_meta(pos)
+					swap_node(pos, meta, true)
+				else
+					minetest.get_node_timer(pos):start(1.0)
+				end
+				return inv:add_item("src", stack)
+			end,
+			can_insert = function(pos, node, stack, direction)
+				local meta = minetest.get_meta(pos)
+				local inv = meta:get_inventory()
+				return inv:room_for_item("src", stack)
+			end,
+			input_inventory = "dst",
+			connect_sides = {left = 1, right = 1, front = 1, back = 1, bottom = 1, top = 1}
+		}
+	end
+
+	if idx == 3 then
+		tiles_data[1] = "gravelsieve_top.png"
+		not_in_creative_inventory = 0
+	else
+		not_in_creative_inventory = 1
+	end
+
+
+	minetest.register_node(node_name..idx, {
+		description = description,
+		tiles = tiles_data,
+		drawtype = "nodebox",
+        drop = node_name,
+		
+		tube = tube_info,     --  NEW
+		
+		node_box = {
+			type = "fixed",
+			fixed = nodebox_data,
+		},
+		selection_box = {
+			type = "fixed",
+			fixed = { -8/16, -8/16, -8/16,   8/16, 4/16, 8/16 },
+		},
+
+		on_timer = sieve_node_timer,
+
+		on_construct = function(pos)
+			local meta = minetest.get_meta(pos)
+			meta:set_int("idx", idx)        -- for the 4 sieve phases
+			meta:set_int("gravel_cnt", 0)   -- counter to switch between gravel and sieved gravel
+			meta:set_string("node_name", node_name)
+			meta:set_string("formspec", sieve_formspec)
+			local inv = meta:get_inventory()
+			inv:set_size('src', 1)
+			inv:set_size('dst', 16)
+		end,
+		
+		-- Pipeworks support
+		after_dig_node = pipeworks_after_dig,
+
+		after_place_node = function(pos, placer)
+			local meta = minetest.get_meta(pos)
+			meta:set_string("infotext", "Gravel Sieve")
+			
+			-- Pipeworks support
+			pipeworks_after_place(pos, placer)
+		end,
+			
+		on_metadata_inventory_move = function(pos)
+			if automatic == 0 then
+				local meta = minetest.get_meta(pos)
+				swap_node(pos, meta, true)
+			else
+				minetest.get_node_timer(pos):start(1.0)
+			end
+		end,
+
+		on_metadata_inventory_take = function(pos)
+			if automatic == 0 then
+				local meta = minetest.get_meta(pos)
+				local inv = meta:get_inventory()
+				if inv:is_empty("src") then
+					-- sieve should be empty
+					meta:set_int("idx", 2)
+					swap_node(pos, meta, false)
+					meta:set_int("gravel_cnt", 0)
+				end
+			else
+				minetest.get_node_timer(pos):start(1.0)
+			end
+		end,
+
+		on_metadata_inventory_put = function(pos)
+			if automatic == 0 then
+				local meta = minetest.get_meta(pos)
+				swap_node(pos, meta, true)
+			else
+				minetest.get_node_timer(pos):start(1.0)
+			end
+		end,
+
+		on_punch = function(pos, node, puncher, pointed_thing)
+			local meta = minetest.get_meta(pos)
+			local inv = meta:get_inventory()
+			if inv:is_empty("dst") and inv:is_empty("src") then
+				minetest.node_punch(pos, node, puncher, pointed_thing)
+			else
+				sieve_node_timer(pos, 0)
+			end
+		end,
+
+		on_dig = function(pos, node, puncher, pointed_thing)
+			local meta = minetest.get_meta(pos)
+			local inv = meta:get_inventory()
+			if inv:is_empty("dst") and inv:is_empty("src") then
+				minetest.node_dig(pos, node, puncher, pointed_thing)
+			end
+		end,
+
+		allow_metadata_inventory_put = allow_metadata_inventory_put,
+		allow_metadata_inventory_move = allow_metadata_inventory_move,
+		allow_metadata_inventory_take = allow_metadata_inventory_take,
+
+		paramtype = "light",
+		sounds = default.node_sound_wood_defaults(),
+		paramtype2 = "facedir",
+		sunlight_propagates = true,
+		is_ground_content = false,
+		groups = {choppy=2, cracky=1, not_in_creative_inventory=not_in_creative_inventory, tubedevice = 1, tubedevice_receiver = 1},
+		drop = node_name.."3",
+	})
+end
+end
+
+
+------------------------------------------------------------------------
+-- Optional adaption to tubelib
+------------------------------------------------------------------------
+if minetest.global_exists("tubelib") then
+	tubelib.register_node("gravelsieve:auto_sieve3", 
+		{
+			"gravelsieve:auto_sieve0",
+			"gravelsieve:auto_sieve1",
+			"gravelsieve:auto_sieve2",
+		},
+		{
+		on_pull_item = function(pos, side)
+			local meta = minetest.get_meta(pos)
+			return tubelib.get_item(meta, "dst")
+		end,
+		on_push_item = function(pos, side, item)
+			minetest.get_node_timer(pos):start(1.0)
+			local meta = minetest.get_meta(pos)
+			return tubelib.put_item(meta, "src", item)
+		end,
+		on_unpull_item = function(pos, side, item)
+			local meta = minetest.get_meta(pos)
+			return tubelib.put_item(meta, "dst", item)
+		end,
+		on_recv_message = function(pos, topic, payload)
+			if topic == "on" then
+				start_the_machine(pos)
+			elseif topic == "off" then
+				stop_the_machine(pos)
+			end
+		end,
+	})	
+end
+
+minetest.register_node("gravelsieve:sieved_gravel", {
+	description = "Sieved Gravel",
+	tiles = {"default_gravel.png"},
+	groups = {crumbly=2, falling_node=1, not_in_creative_inventory=1},
+	sounds = default.node_sound_gravel_defaults(),
+})
+
+minetest.register_node("gravelsieve:compressed_gravel", {
+	description = "Compressed Gravel",
+	tiles = {"gravelsieve_compressed_gravel.png"},
+	groups = {cracky=2, crumbly = 2, cracky = 2},
+	sounds = default.node_sound_gravel_defaults(),
+})
+
+minetest.register_craft({
+	output = "gravelsieve:sieve",
+	recipe = {
+		{"group:wood", "",                      "group:wood"},
+		{"group:wood", "default:steel_ingot",   "group:wood"},
+		{"group:wood", "",                      "group:wood"},
+	},
+})
+
+minetest.register_craft({
+	output = "gravelsieve:auto_sieve",
+	recipe = {
+		{"gravelsieve:sieve", "default:mese_crystal",  "default:mese_crystal"},
+	},
+})
+
+minetest.register_craft({
+	output = "gravelsieve:compressed_gravel",
+	recipe = {
+		{"gravelsieve:sieved_gravel", "gravelsieve:sieved_gravel"},
+		{"gravelsieve:sieved_gravel", "gravelsieve:sieved_gravel"},
+	},
+})
+
+minetest.register_craft({
+	type = "cooking",
+	output = "default:cobble",
+	recipe = "gravelsieve:compressed_gravel",
+	cooktime = 10,
+})
+
+minetest.register_alias("gravelsieve:sieve", "gravelsieve:sieve3")
+minetest.register_alias("gravelsieve:auto_sieve", "gravelsieve:auto_sieve3")
+
+-- adaption to hopper
+if minetest.get_modpath("hopper") and hopper ~= nil and hopper.add_container ~= nil then
+	hopper:add_container({
+		{"bottom", "gravelsieve:auto_sieve0", "src"}, 
+		{"top", "gravelsieve:auto_sieve0", "dst"},
+		{"side", "gravelsieve:auto_sieve0", "src"},
+		
+		{"bottom", "gravelsieve:auto_sieve1", "src"}, 
+		{"top", "gravelsieve:auto_sieve1", "dst"},
+		{"side", "gravelsieve:auto_sieve1", "src"},
+		
+		{"bottom", "gravelsieve:auto_sieve2", "src"}, 
+		{"top", "gravelsieve:auto_sieve2", "dst"},
+		{"side", "gravelsieve:auto_sieve2", "src"},
+		
+		{"bottom", "gravelsieve:auto_sieve3", "src"}, 
+		{"top", "gravelsieve:auto_sieve3", "dst"},
+		{"side", "gravelsieve:auto_sieve3", "src"},
+	})
+end
+
+-- adaption to Circular Saw
+if minetest.get_modpath("moreblocks") then
+	
+	stairsplus:register_all("gravelsieve", "compressed_gravel", "gravelsieve:compressed_gravel", {
+		description="Compressed Gravel",
+		groups={cracky=2, crumbly=2, choppy=2, not_in_creative_inventory=1},
+		tiles = {"gravelsieve_compressed_gravel.png"},
+		sounds = default.node_sound_stone_defaults(),
+	})
+end
+
+

gravelsieve/mod.conf

@@ -0,0 +1 @@
+name=gravelsieve

gravelsieve/settingtypes.txt

@@ -0,0 +1,5 @@
+# Rarity factor to find ores when sieving with the Gravel Sieve
+# 1.0 is according to the mapgen generator 
+# 2.0 means half as many ores as result
+# 0.5 means twice as many ores as result
+gravelsieve_ore_rarity (Rarity factor to find ores) float 1

modpack.txt

@@ -0,0 +1 @@
+The presence of this file indicates that the current folder is a modpack.

smartline/README.md

@@ -0,0 +1,41 @@
+# SmartLine \[smartline\]
+
+This tubelib extension provides small and smart sensors, actors and controllers.
+
+![SmartLine](https://github.com/joe7575/techpack/blob/master/smartline/screenshot.png)
+
+The most important and smart node of SmartLine is the SmartLine Controller, a 'computer' to control and monitor Tubelib based machines.
+You don't need any programming skills, it is more like a configuration according to the "IF this THEN that" concept:
+
+    IF <cond1> OR <cond2> THEN <action>
+    IF <cond1> AND <cond2> THEN <action>
+    
+Examples for conditions are:
+ - the Player Detector detects a player
+ - a button is pressed
+ - a node state is fault, blocked, standby,...
+ - a timer is expired 
+
+Examples for actions are:
+ - switch on/off tubelib nodes, like lamps, door blocks, machines
+ - send mail/chat messages to the owner
+ - output a text message to the display
+ - set timer variables 
+ - set/reset flag variables
+
+The mod comes with several new nodes, all in a smart and small housing:
+ - a Player Detector, sending on/off commands to connected nodes
+ - a Smart Button, sending on/off commands to connected nodes
+ - a Display for text outputs of the controller
+ - a Signal Tower, with green, amber, red lights to signal error/fault states
+ - a Timer (derived from Tubelib Addons2), for daytime based actions
+ - a Sequencer (derived from Tubelib Addons2), for time triggered actions (time in seconds)
+
+
+API Reference: ![api.md](https://github.com/joe7575/techpack/blob/master/smartline/api.md)
+
+
+## Dependencies
+tubelib, default, doors  
+optional: display_lib, font_lib, mail  
+

smartline/api.md

@@ -0,0 +1,121 @@
+# SmartLine Controller API
+
+
+The SmartLine Controller provides the following API to register additional condition and action commands from other mods:
+
+* smartline.register_condition(name, condition definition)
+* smartline.register_action(name, action definition)
+
+The controller executes up to 10 rules every second. Each rule consists of:
+- two condition functions 
+- one logical operator (and/or)
+- one action function
+
+Depending on the operator, one or both condition functions have to return true, so that the action function is called.
+If the action is called, the action related flag (a1..a10) is automatically set and can be used in  
+subsequent rules to trigger further actions without the need to evaluate both conditions again.
+
+The controller executes all rules once per second. Independent how long the input condition stays 'true',
+the corresponding action will be triggered only once. The condition has to become false and then true again, to 
+re-trigger/execute the action again.
+
+The Controller supports the following variables:
+- binary flags (f1..f8) to store states (true/false)
+- timer variables (t1..t8), decremented each second. Used to execute actions time based
+- input values (referenced via node number) to evaluate received commands (on/off) from other tubelib nodes
+- action flags (a1..a10) )to store the action state from previous executed rules
+
+All variables are stored non volatile (as long as the controller is running).
+
+Each registered condition and action has the function `on_execute`  which is called for each rule (every second).
+* The condition function has to return true or false, depending if the condition is true or not.
+* The action function has to execute the defined action.
+
+In addition each registered condition and action has the function `button_label`, which determines the button label
+for the Controller main formspec. Please note that the maximum number of visible characters for the button label is
+something about 15.
+
+See `commands.lua` as reference. All predefined SmartLine Controller commands are registered via `commands.lua`.
+
+## Prototypes
+
+```LUA
+smartline.register_condition("mymod;mycond", {
+	title = "my condition",
+	formspec = {},
+	on_execute = function(data, flags, timers, inputs, actions) 
+	-- data:    table with the formspec data 
+	-- flag:    table with the flag values
+	-- timers:  table with the timer values
+	-- inputs:  table with the input values
+	-- actions: table with the action values
+	end,
+	button_label = function(data) 
+	   return "button label"
+	end,
+})
+```
+
+
+```LUA
+smartline.register_action(name, {
+	title = "my action",
+	formspec = {},
+	on_execute = function(data, flags, timers, inputs) 
+	-- data:    table with the formspec data 
+	-- flag:    table with the flag values
+	-- timers:  table with the timer values
+	-- inputs:  table with the input values
+	end,
+	button_label = function(data) 
+	   return "button label"
+	end,
+})
+```
+
+The 'title' is used in the main menu for the condition and action selection dialog.
+The 'formspec' table defines the condition/action related form for additional user parameters.
+It supports the following subset of the minetest formspec elements:
+
+  - textlist
+  - field
+  - label
+
+Please note that size and position is automatically determined.
+All other attributes are according to the original formspec.
+Example:
+
+```LUA
+formspec = {
+	{
+		type = "field",                          -- formspec element
+		name = "number",                         -- reference key for the table 'data'
+		label = "input from node with number",   -- label shown above of the element
+		default = "",                            -- default value
+	},
+	{
+		type = "textlist",                       -- formspec element
+		name = "value",                          -- reference key for the table 'data'
+		label = "is",                            -- label shown above of the element
+		choices = "on,off",                      -- list elements
+		default = 1,                             -- first list element as default value
+	},
+	{
+		type = "label",
+		name = "lbl",                                -- not really used, but internally needed
+		label = "Hint: Connect the input nodes with the controller", 
+	},
+}
+```
+
+The table 'data' includes the condition/action related 'formspec' data. 
+For the above 'formspec' example, it is:
+
+```LUA
+    data = {
+        number = <string>,       -- the entered value of the "field",
+        value = <number>,        -- the number of the selected element of the "textlist"
+        value_text = <string>,   -- in addition the text of the selected element of the "textlist"
+    }
+```
+

smartline/button.lua

@@ -0,0 +1,189 @@
+--[[
+
+	SmartLine
+	=========
+
+	Copyright (C) 2018 Joachim Stolberg
+
+	LGPLv2.1+
+	See LICENSE.txt for more information
+
+	button.lua:
+	Derived from Tubelib button
+
+]]--
+
+
+local function switch_on(pos, node)
+	node.name = "smartline:button_active"
+	minetest.swap_node(pos, node)
+	minetest.sound_play("button", {
+			pos = pos,
+			gain = 0.5,
+			max_hear_distance = 5,
+		})
+	local meta = minetest.get_meta(pos)
+	local own_num = meta:get_string("own_num")
+	local numbers = meta:get_string("numbers")
+	local cycle_time = meta:get_int("cycle_time")
+	if cycle_time > 0 then 	-- button mode?
+		minetest.get_node_timer(pos):start(cycle_time)
+	end
+	local placer_name = meta:get_string("placer_name")
+	local clicker_name = nil
+	if meta:get_string("public") == "false" then
+		clicker_name = meta:get_string("clicker_name")
+	end
+	tubelib.send_message(numbers, placer_name, clicker_name, "on", own_num)
+end
+
+local function switch_off(pos)
+	local node = minetest.get_node(pos)
+	node.name = "smartline:button"
+	minetest.swap_node(pos, node)
+	minetest.get_node_timer(pos):stop()
+	minetest.sound_play("button", {
+			pos = pos,
+			gain = 0.5,
+			max_hear_distance = 5,
+		})
+	local meta = minetest.get_meta(pos)
+	local own_num = meta:get_string("own_num")
+	local numbers = meta:get_string("numbers")
+	local placer_name = meta:get_string("placer_name")
+	tubelib.send_message(numbers, placer_name, nil, "off", own_num)
+end
+
+
+minetest.register_node("smartline:button", {
+	description = "SmartLine Button/Switch",
+	inventory_image = "smartline_button_inventory.png",
+	tiles = {
+		-- up, down, right, left, back, front
+		"smartline.png",
+		"smartline.png",
+		"smartline.png",
+		"smartline.png",
+		"smartline.png",
+		"smartline.png^smartline_button_off.png",
+	},
+
+	drawtype = "nodebox",
+	node_box = {
+		type = "fixed",
+		fixed = {
+			{ -6/32, -6/32, 14/32,  6/32,  6/32, 16/32},
+		},
+	},
+	
+	after_place_node = function(pos, placer)
+		local meta = minetest.get_meta(pos)
+		local own_num = tubelib.add_node(pos, "smartline:button")
+		meta:set_string("own_num", own_num)
+		meta:set_string("formspec", "size[5,6]"..
+		"dropdown[0.2,0;3;type;switch,button 2s,button 4s,button 8s,button 16s;1]".. 
+		"field[0.5,2;3,1;numbers;Insert destination block number(s);]" ..
+		"checkbox[1,3;public;public;false]"..
+		"button_exit[1,4;2,1;exit;Save]")
+		meta:set_string("placer_name", placer:get_player_name())
+		meta:set_string("public", "false")
+		meta:set_int("cycle_time", 0)
+		meta:set_string("infotext", "SmartLine Button "..own_num)
+	end,
+
+	on_receive_fields = function(pos, formname, fields, player)
+		local meta = minetest.get_meta(pos)
+		if tubelib.check_numbers(fields.numbers) then
+			meta:set_string("numbers", fields.numbers)
+			local own_num = meta:get_string("own_num")
+			meta:set_string("infotext", "SmartLine Button "..own_num..", connected with block "..fields.numbers)
+		else
+			return
+		end
+		if fields.public then
+			meta:set_string("public", fields.public)
+		end
+		local cycle_time = nil
+		if fields.type == "switch" then
+			cycle_time = 0
+		elseif fields.type == "button 2s" then
+			cycle_time = 2
+		elseif fields.type == "button 4s" then
+			cycle_time = 4
+		elseif fields.type == "button 8s" then
+			cycle_time = 8
+		elseif fields.type == "button 16s" then
+			cycle_time = 16
+		end
+		if cycle_time ~= nil then
+			meta:set_int("cycle_time", cycle_time)
+		end
+		if fields.exit then
+			meta:set_string("formspec", nil)
+		end
+	end,
+	
+	on_rightclick = function(pos, node, clicker)
+		local meta = minetest.get_meta(pos)
+		if meta:get_string("numbers") then
+			meta:set_string("clicker_name", clicker:get_player_name())
+			switch_on(pos, node)
+		end
+	end,
+
+	paramtype = "light",
+	sunlight_propagates = true,
+	paramtype2 = "facedir",
+	groups = {cracky=2, crumbly=2},
+	is_ground_content = false,
+	sounds = default.node_sound_wood_defaults(),
+})
+
+
+minetest.register_node("smartline:button_active", {
+	description = "SmartLine Button/Switch",
+	tiles = {
+		-- up, down, right, left, back, front
+		"smartline.png",
+		"smartline.png",
+		"smartline.png",
+		"smartline.png",
+		"smartline.png",
+		"smartline.png^smartline_button_on.png",
+	},
+
+	drawtype = "nodebox",
+	node_box = {
+		type = "fixed",
+		fixed = {
+			{ -6/32, -6/32, 14/32,  6/32,  6/32, 16/32},
+		},
+	},
+	
+	on_rightclick = function(pos, node, clicker)
+		local meta = minetest.get_meta(pos)
+		meta:set_string("clicker_name", clicker:get_player_name())
+		if meta:get_int("cycle_time") == nil or meta:get_int("cycle_time") == 0 then
+			switch_off(pos, node)
+		end
+	end,
+
+	on_timer = switch_off,
+
+	paramtype = "light",
+	sunlight_propagates = true,
+	paramtype2 = "facedir",
+	groups = {cracky=2, crumbly=2, not_in_creative_inventory=1},
+	drop = "smartline:button",
+	is_ground_content = false,
+	sounds = default.node_sound_wood_defaults(),
+})
+
+minetest.register_craft({
+	output = "smartline:button",
+	recipe = {
+		{"", "", ""},
+		{"dye:blue", "default:copper_ingot", "tubelib:wlanchip"},
+		{"", "", ""},
+	},
+})

smartline/commands.lua

@@ -0,0 +1,611 @@
+--[[
+
+	SmartLine
+	=========
+
+	Copyright (C) 2018 Joachim Stolberg
+
+	LGPLv2.1+
+	See LICENSE.txt for more information
+
+	command.lua:
+	
+	Register all basic controller commands
+
+]]--
+
+smartline.register_condition("default", {
+	title = "",
+	formspec = {},
+	on_execute = function(data, flags, timers, inputs, actions) end,
+	button_label = function(data) return ""	end,
+})
+
+smartline.register_action("default", {
+	title = "",
+	formspec = {},
+	on_execute = function(data, flags, timers, inputs) end,
+	button_label = function(data) return ""	end,
+})
+
+
+smartline.register_condition("true", {
+	title = "true",
+	formspec = {},
+	on_execute = function(data, flags, timers, inputs, actions) 
+		return true
+	end,
+	button_label = function(data) 
+		return "true"
+	end,
+})
+
+smartline.register_condition("false", {
+	title = "false",
+	formspec = {},
+	on_execute = function(data, flags, timers, inputs, actions) 
+		return false
+	end,
+	button_label = function(data) 
+		return "false"
+	end,
+})
+
+smartline.register_condition("flag", {
+	title = "flag test",
+	formspec = {
+		{
+			type = "textlist", 
+			name = "flag",
+			label = "flag",      
+			choices = "f1,f2,f3,f4,f5,f6,f7,f8", 
+			default = 1,
+		},
+		{
+			type = "textlist", 
+			name = "value", 
+			label = "is", 
+			choices = "true,false", 
+			default = 1,
+		},
+		{
+			type = "label", 
+			name = "lbl", 
+			label = "Hint: Don't forget to reset the flag again.", 
+		},
+	},
+	on_execute = function(data, flags, timers, inputs, actions) 
+		return flags[data.flag] == data.value_text
+	end,
+	button_label = function(data) 
+		return data.flag_text.."=="..data.value_text
+	end,
+})
+
+smartline.register_action("flag", {
+	title = "flag set",
+	formspec = {
+		{
+			type = "textlist", 
+			name = "flag",
+			label = "set flag",      
+			choices = "f1,f2,f3,f4,f5,f6,f7,f8", 
+			default = 1,
+		},
+		{
+			type = "textlist", 
+			name = "value", 
+			label = "to value", 
+			choices = "true,false", 
+			default = 1,
+		},
+		{
+			type = "label", 
+			name = "lbl", 
+			label = "Hint: Flags are stored permanently and can be used by other rules.", 
+		},
+	},
+	on_execute = function(data, flags, timers, number) 
+		flags[data.flag] = data.value_text
+	end,
+	button_label = function(data) 
+		return data.flag_text.."="..data.value_text
+	end,
+})
+
+smartline.register_condition("input", {
+	title = "check input",
+	formspec = {
+		{
+			type = "field",
+			name = "number",
+			label = "input from node with number",
+			default = "",
+		},
+		{
+			type = "textlist",
+			name = "value",
+			label = "is",
+			choices = "on,off",
+			default = 1,
+		},
+		{
+			type = "label", 
+			name = "lbl", 
+			label = "Hint: An input is only available,\nif the sending node is connected with the controller.", 
+		},
+	},
+	on_execute = function(data, flags, timers, inputs, actions) 
+		return inputs[data.number] == data.value_text
+	end,
+	button_label = function(data) 
+		return "i("..data.number..")=="..data.value_text 
+	end,
+})
+
+
+smartline.register_condition("timer", {
+	title = "timer expired",
+	formspec = {
+		{
+			type = "textlist", 
+			name = "timer",
+			label = "timer expired",
+			choices = "t1,t2,t3,t4,t5,t6,t7,t8", 
+			default = 1,
+		},
+	},
+	on_execute = function(data, flags, timers, inputs, actions) 
+		return timers[data.timer] == 0
+	end,
+	button_label = function(data) 
+		return data.timer_text.." expired"
+	end,
+})
+
+smartline.register_action("timer", {
+	title = "timer start",
+	formspec = {
+		{
+			type = "textlist", 
+			name = "timer",
+			label = "start timer",      
+			choices = "t1,t2,t3,t4,t5,t6,t7,t8", 
+			default = 1,
+		},
+		{
+			type = "field", 
+			name = "value", 
+			label = "value in sec.", 
+			default = "",
+		},
+	},
+	on_execute = function(data, flags, timers, number) 
+		timers[data.timer] = tonumber(data.value) or 0
+	end,
+	button_label = function(data) 
+		return data.timer_text.."="..data.value 
+	end,
+})
+
+smartline.register_condition("pusher", {
+	title = "Pusher state",
+	formspec = {
+		{
+			type = "field",
+			name = "number",
+			label = "state from Pusher with number",
+			default = "",
+		},
+		{
+			type = "textlist",
+			name = "value",
+			label = "is",
+			choices = "stopped,running,standby,blocked,fault",
+			default = 1,
+		},
+		{
+			type = "label", 
+			name = "lbl", 
+			label = "Hint:\n - standby means 'nothing to do'\n - blocked means 'inventory is full'", 
+		},
+	},
+	
+	on_execute = function(data, flags, timers, inputs, actions) 
+		return tubelib.send_request(data.number, "state", "") == data.value_text
+	end,
+	button_label = function(data) 
+		return "st("..data.number..")=="..string.sub(data.value_text or "???", 1, 4).."."
+	end,
+})
+
+smartline.register_condition("fuel", {
+	title = "fuel state",
+	formspec = {
+		{
+			type = "field",
+			name = "number",
+			label = "fuel state from node with number",
+			default = "",
+		},
+		{
+			type = "textlist",
+			name = "value",
+			label = "is",
+			choices = "full,empty,not full,not empty",
+			default = 1,
+		},
+	},
+	
+	on_execute = function(data, flags, timers, inputs, actions) 
+		if data.value > 2 then
+			return tubelib.send_request(data.number, "fuel", nil) ~= string.sub(data.value_text or "???", 5)
+		else
+			return tubelib.send_request(data.number, "fuel", nil) == data.value_text
+		end
+	end,
+	button_label = function(data) 
+		if data.value > 2 then
+			return "st("..data.number..")<>"..string.sub(data.value_text or "???", 5)
+		else
+			return "st("..data.number..")=="..data.value_text
+		end
+	end,
+})
+
+smartline.register_condition("signaltower", {
+	title = "Signal Tower state",
+	formspec = {
+		{
+			type = "field",
+			name = "number",
+			label = "state from Signal Tower with number",
+			default = "",
+		},
+		{
+			type = "textlist",
+			name = "value",
+			label = "is",
+			choices = "off,green,amber,red,not off,not green,not amber,not red",
+			default = 1,
+		},
+		{
+			type = "label", 
+			name = "lbl", 
+			label = "Hint: Works also for Signal Towers in unloaded areas.", 
+		},
+	},
+	
+	on_execute = function(data, flags, timers, inputs, actions) 
+		if data.value > 4 then
+			return tubelib.send_request(data.number, "state", nil) ~= string.sub(data.value_text or "???", 5)
+		else
+			return tubelib.send_request(data.number, "state", nil) == data.value_text
+		end
+	end,
+	button_label = function(data) 
+		if data.value > 4 then
+			return "sig("..data.number..")<>"..string.sub(data.value_text or "???", 5)
+		else
+			return "sig("..data.number..")=="..data.value_text
+		end
+	end,
+})
+
+smartline.register_action("signaltower", {
+	title = "Signal Tower command",
+	formspec = {
+		{
+			type = "field", 
+			name = "number", 
+			label = "set Signal Tower with number", 
+			default = "",
+		},
+		{
+			type = "textlist", 
+			name = "value",
+			label = "to color",      
+			choices = "off,green,amber,red", 
+			default = 1,
+		},
+	},
+	on_execute = function(data, flags, timers, number) 
+		tubelib.send_message(data.number, data.owner, nil, data.value_text, number)
+	end,
+	button_label = function(data) 
+		return "sig("..data.number..","..data.value_text..")"
+	end,
+})
+
+smartline.register_action("switch", {
+	title = "switch nodes on/off",
+	formspec = {
+		{
+			type = "field", 
+			name = "number", 
+			label = "set node with number", 
+			default = "",
+		},
+		{
+			type = "textlist", 
+			name = "value",
+			label = "to state",      
+			choices = "on,off", 
+			default = 1,
+		},
+		{
+			type = "label", 
+			name = "lbl", 
+			label = "Hint: Used for pushers, lamps, machines, gates,...", 
+		},
+	},
+	on_execute = function(data, flags, timers, number) 
+		tubelib.send_message(data.number, data.owner, nil, data.value_text, number)
+	end,
+	button_label = function(data) 
+		return "cmnd("..data.number..","..data.value_text..")"
+	end,
+})
+
+smartline.register_action("display1", {
+	title = "Display: add one line",
+	formspec = {
+		{
+			type = "field", 
+			name = "number", 
+			label = "output to Display with number", 
+			default = "",
+		},
+		{
+			type = "field", 
+			name = "text",
+			label = "the following text",      
+			default = "",
+		},
+		{
+			type = "label", 
+			name = "lbl", 
+			label = "Hint: Works also for Displays in unloaded areas.", 
+		},
+	},
+	on_execute = function(data, flags, timers, number) 
+		tubelib.send_message(data.number, data.owner, nil, "text", data.text)
+	end,
+	button_label = function(data) 
+		return "display("..data.number..")"
+	end,
+})
+
+smartline.register_action("display2", {
+	title = "Display: overwrite one line",
+	formspec = {
+		{
+			type = "field", 
+			name = "number", 
+			label = "output to Display with number", 
+			default = "",
+		},
+		{
+			type = "textlist", 
+			name = "row", 
+			label = "Display line", 
+			choices = "1,2,3,4,5,6,7,8,9", 
+			default = 1,
+		},
+		{
+			type = "field", 
+			name = "text",
+			label = "the following text",      
+			default = "",
+		},
+		{
+			type = "label", 
+			name = "lbl", 
+			label = "Hint: Works also for Displays in unloaded areas.", 
+		},
+	},
+	on_execute = function(data, flags, timers, number) 
+		local payload = {row = data.row, str = data.text}
+		tubelib.send_message(data.number, data.owner, nil, "row", payload)
+	end,
+	button_label = function(data) 
+		return "display("..data.number..")"
+	end,
+})
+
+smartline.register_action("display3", {
+	title = "Display: player name",
+	formspec = {
+		{
+			type = "field", 
+			name = "number", 
+			label = "output to Display with number", 
+			default = "",
+		},
+		{
+			type = "field", 
+			name = "text",
+			label = "the following text",      
+			default = "",
+		},
+		{
+			type = "label", 
+			name = "lbl", 
+			label = "Hint: use a '*' character as reference to the player name", 
+		},
+	},
+	on_execute = function(data, flags, timers, number) 
+		local text = string.gsub(data.text, "*", flags.name or "<unknown>")
+		tubelib.send_message(data.number, data.owner, nil, "text", text)
+	end,
+	button_label = function(data) 
+		return "display(<name>)"
+	end,
+})
+
+smartline.register_action("display4", {
+	title = "Display: Clear screen",
+	formspec = {
+		{
+			type = "field", 
+			name = "number", 
+			label = "Display number", 
+			default = "",
+		},
+	},
+	on_execute = function(data, flags, timers, number) 
+		tubelib.send_message(data.number, data.owner, nil, "clear", "")
+	end,
+	button_label = function(data) 
+		return "Clear screen"
+	end,
+})
+
+if minetest.get_modpath("mail") and mail ~= nil then
+	smartline.register_action("mail", {
+		title = "mail",
+		formspec = {
+			{
+				type = "field", 
+				name = "text",
+				label = "send the message",      
+				default = "",
+			},
+		},
+		on_execute = function(data, flags, timers, number) 
+			mail.send("Server", data.owner, "[SmartLine Controller]", data.text)
+		end,
+		button_label = function(data) 
+			return "mail(...)"
+		end,
+	})
+end
+
+smartline.register_action("chat", {
+	title = "chat",
+	formspec = {
+		{
+			type = "field", 
+			name = "text",
+			label = "send the message",      
+			default = "",
+		},
+	},
+	on_execute = function(data, flags, timers, number)
+		minetest.chat_send_player(data.owner, "[SmartLine Controller] "..data.text)
+	end,
+	button_label = function(data) 
+		return "chat(...)"
+	end,
+})
+
+local function door_toggle(pos, owner, state)
+	pos = minetest.string_to_pos("("..pos..")")
+	if pos then
+		local door = doors.get(pos)
+		if door then
+			local player = {
+				get_player_name = function() return owner end,
+			}
+			if state == "open" then
+				door:open(player)
+			elseif state == "close" then
+				door:close(player)
+			end
+		end
+	end
+end
+
+smartline.register_action("door", {
+	title = "doors open/close",
+	formspec = {
+		{
+			type = "field", 
+			name = "pos", 
+			label = "door position like: 123,7,-1200", 
+			default = "",
+		},
+		{
+			type = "textlist", 
+			name = "state",
+			label = "set",      
+			choices = "open,close", 
+			default = 1,
+		},
+		{
+			type = "label", 
+			name = "lbl1", 
+			label = "For standard doors like the Steel Door", 
+		},
+		{
+			type = "label", 
+			name = "lbl2", 
+			label = "Hint: use a marker stick to determine the door position", 
+		},
+	},
+	on_execute = function(data, flags, timers, number) 
+		door_toggle(data.pos, data.owner, data.state_text)
+	end,
+	button_label = function(data) 
+		return "door("..data.state_text..")"
+	end,
+})
+
+smartline.register_condition("playerdetector", {
+	title = "detected player name",
+	formspec = {
+		{
+			type = "field",
+			name = "number",
+			label = "name from player detector with number",
+			default = "",
+		},
+		{
+			type = "field",
+			name = "name",
+			label = "is",
+			default = "",
+		},
+		{
+			type = "label", 
+			name = "lbl", 
+			label = "Hint: use a '*' character for all player names", 
+		},
+	},
+	
+	on_execute = function(data, flags, timers, inputs, actions) 
+		flags.name = tubelib.send_request(data.number, "name", nil)
+		return (data.name == "*" and flags.name ~= "") or flags.name == data.name
+	end,
+	button_label = function(data) 
+		if string.len(data.name) > 6 then
+			return "name=="..string.sub(data.name or "???", 1, 6).."."
+		end
+		return "name=="..data.name
+	end,
+})
+
+smartline.register_condition("action", {
+	title = "action",
+	formspec = {
+		{
+			type = "textlist", 
+			name = "action",
+			label = "action is executed",      
+			choices = "a1,a2,a3,a4,a5,a6,a7,a8,a9,a10", 
+			default = 1,
+		},
+		{
+			type = "label", 
+			name = "lbl", 
+			label = "Hint: The corresponding flag is set for each\nexecute action. Useful to execute\nmore than one action with one condition.", 
+		},
+	},
+	on_execute = function(data, flags, timers, inputs, actions) 
+		return actions[data.action] == true
+	end,
+	button_label = function(data) 
+		return "action"..data.action
+	end,
+})
+

smartline/controller.lua

@@ -0,0 +1,937 @@
+--[[
+
+	SmartLine
+	=========
+
+	Copyright (C) 2018 Joachim Stolberg
+
+	LGPLv2.1+
+	See LICENSE.txt for more information
+
+	controller.lua:
+
+]]--
+
+
+local NUM_RULES = 10
+
+local mail_exists = minetest.get_modpath("mail") and mail ~= nil
+ 
+local sHELP = [[SmartLine Controller Help
+
+Control other nodes by means of rules, according to:
+    IF <cond1> and/or <cond2> THEN <action>
+
+These rules allow to execute actions based on conditions.
+Examples for conditions are:
+ - the Player Detector detects a player
+ - a button is pressed
+ - a node state is fault, blocked, standby,...
+ - a timer is expired 
+ 
+Actions are:
+ - switch on/off tubelib nodes, like lamps, door blocks, machines
+ - send mail/chat messages to the owner
+ - output a text message to the display
+ - set timer variables 
+ - set/reset flag variables
+ 
+Variables and timers: 
+ - 8 flags (set/reset) can be used to store conditions 
+    for later use.
+ - Action flags (one flag for each rule, set when action is executed)
+    The flag can be used as condition for subsequent rules.
+ - 8 timers (resolution in seconds) can be use
+   for delayed actions. 
+
+The controller executes all rules once per second. 
+Independent how long the input condition stays 'true',
+the corresponding action will be triggered only once.
+The condition has to become false and then true again, to 
+re-trigger/execute the action again.
+
+The 'label' has no function. It is only used
+to give rules a name.
+
+Edit command examples:
+ - 'x 1 8'  exchange rows 1 with row 8
+ - 'c 1 2'  copy row 1 to 2
+ - 'd 3'    delete row 3
+
+The state view shows the current state of all rules.
+The colors show, if conditions are true or false and
+if actions were already executed or not.
+It has a 'update' button to update the view.
+
+For more information, see: goo.gl/wZ5GUR
+]]
+
+local sOUTPUT = "Press 'help' for edit commands" 
+ 
+--
+-- Helper functions
+--
+local function create_kv_list(elem) 
+	local a = {}
+	for i,v in ipairs(elem) do
+		a[v] = i
+	end
+	return a
+end
+
+local function output(label, prefix, postfix, kvTbl)
+	local tbl = {label..": "}
+	for k,v in pairs(kvTbl) do
+		tbl[#tbl+1] = prefix..k..postfix.."="..v..", "
+	end
+	return table.concat(tbl)
+end
+
+
+--
+-- Conditions
+--
+
+-- tables with all data from condition/action registrations
+local kvRegisteredCond = {}
+local kvRegisteredActn = {}
+
+-- list of keys for conditions/actions
+local aCondTypes = {}
+local aActnTypes = {}
+
+-- list of titles for conditions/actions
+local aCondTitles = {}
+local aActnTitles = {}
+
+-- table with runtime functions
+local CondRunTimeHandlers = {}
+local ActnRunTimeHandlers = {}
+
+
+local function eval_cond(data, flags, timers, inputs, actions)
+	return CondRunTimeHandlers[data.__idx__](data, flags, timers, inputs, actions) and 1 or 0
+end
+
+local function exec_action(data, flags, timers, number)
+	ActnRunTimeHandlers[data.__idx__](data, flags, timers, number)
+end
+
+smartline = {}
+
+--
+-- API functions for condition/action registrations
+--
+function smartline.register_condition(key, tData)
+	table.insert(CondRunTimeHandlers, tData.on_execute)
+	table.insert(aCondTypes, key)
+	table.insert(aCondTitles, tData.title)
+	tData.__idx__ = #aCondTypes
+	if kvRegisteredCond[key] ~= nil then
+		print("[SmartLine] Condition registration error "..key)
+		return
+	end
+	kvRegisteredCond[key] = tData
+	for _,item in ipairs(tData.formspec) do
+		if item.type == "textlist" then
+			item.tChoices = string.split(item.choices, ",")
+			item.num_choices = #item.tChoices
+		end
+	end
+end
+
+function smartline.register_action(key, tData)
+	table.insert(ActnRunTimeHandlers, tData.on_execute)
+	table.insert(aActnTypes, key)
+	table.insert(aActnTitles, tData.title)
+	tData.__idx__ = #aActnTypes
+	if kvRegisteredActn[key] ~= nil then
+		print("[SmartLine] Action registration error "..key)
+		return
+	end
+	kvRegisteredActn[key] = tData
+	for _,item in ipairs(tData.formspec) do
+		if item.type == "textlist" then
+			item.tChoices = string.split(item.choices, ",")
+			item.num_choices = #item.tChoices
+		end
+	end
+end
+
+
+--
+-- Formspec
+--
+
+-- Determine the selected submenu and return the corresponding
+-- formspec definition.
+-- postfix: row/culumn info like "11" or "a2"
+-- type: "cond" or "actn"
+-- fs_data: formspec data
+local function get_active_subm_definition(postfix, type, fs_data)
+	local idx = 1
+	local fs_definition = {}
+	if type == "cond" then
+		idx = fs_data["subm"..postfix.."_cond"] or 1
+		local key = aCondTypes[idx]
+		fs_definition = kvRegisteredCond[key]
+	elseif type == "actn" then
+		idx = fs_data["subm"..postfix.."_actn"] or 1
+		local key = aActnTypes[idx]
+		fs_definition = kvRegisteredActn[key]
+	end
+	return idx, fs_definition
+end
+
+-- Extract runtime relevant data from the given submenu 
+-- postfix: row/culum info like "11" or "a2"
+-- fs_definition: submenu formspec definition
+-- fs_data: formspec data
+local function get_subm_data(postfix, fs_definition, fs_data)
+	local data = {}
+	for idx,elem in ipairs(fs_definition.formspec) do
+		if elem.type == "field" then	
+			data[elem.name] = fs_data["subm"..postfix.."_"..elem.name] or "?"
+		elseif elem.type == "textlist" then	
+			local num = tonumber(fs_data["subm"..postfix.."_"..elem.name]) or 1
+			num = math.min(num, elem.num_choices)
+			data[elem.name] = num
+			data[elem.name.."_text"] = elem.tChoices[num]
+		end
+	end
+	-- type of the condition/action
+	data.__idx__ = fs_definition.__idx__
+	return data
+end
+
+-- Copy field/formspec data to the table fs_data
+-- fs_definition: submenu formspec definituion
+-- fields: formspec input
+-- fs_data: formspec data
+local function field2fs_data(fs_definition, fields, fs_data)
+	for idx,elem in ipairs(fs_definition.formspec) do
+		local key = "subm"..fields._postfix_.."_"..elem.name
+		if elem.type == "field" then	
+			if fields[elem.name] then
+				fs_data[key] = fields[elem.name]
+			end
+		elseif elem.type == "textlist" then	
+			local evt = minetest.explode_textlist_event(fields[elem.name])
+			if evt.type == "CHG" then
+				fs_data[key] = evt.index
+			end
+		end
+		if fs_data[key] == nil then
+			fs_data[key] = elem.default
+		end
+	end
+	return fs_data
+end
+
+local function add_controls_to_table(tbl, postfix, fs_data, fs_definition)
+	local val = ""
+	local offs = 2.4
+	for idx,elem in ipairs(fs_definition.formspec) do
+		if elem.label then
+			tbl[#tbl+1] = "label[0,"..offs..";"..elem.label.."]"
+			offs = offs + 0.5
+		end
+		if elem.type == "field" then
+			val = fs_data["subm"..postfix.."_"..elem.name] or elem.default
+			tbl[#tbl+1] = "field[0.3,"..(offs+0.2)..";8.2,1;"..elem.name..";;"..val.."]"
+			offs = offs + 0.9
+		elseif elem.type == "textlist" then
+			val = fs_data["subm"..postfix.."_"..elem.name] or elem.default
+			tbl[#tbl+1] = "textlist[0.0,"..(offs)..";8,1.4;"..elem.name..";"..elem.choices..";"..val.."]"
+			offs = offs + 1.8
+		end
+	end
+	return tbl
+end
+
+local function runtime_data(postfix, type, fs_data)
+	local _,fs_definition = get_active_subm_definition(postfix, type, fs_data)
+	return get_subm_data(postfix, fs_definition, fs_data)
+end
+
+local function decrement_timers(timers)
+	for idx,_ in ipairs(timers) do
+		timers[idx] = tonumber(timers[idx])
+		if timers[idx] >= 0 then
+			timers[idx] = timers[idx] - 1
+		end
+	end
+end
+
+
+--
+-- Condition formspec
+--
+local function formspec_cond(_postfix_, fs_data)
+	local tbl = {"size[8.2,10]"..
+		default.gui_bg..
+		default.gui_bg_img..
+		default.gui_slots..
+		"field[0,0;0,0;_type_;;cond]"..
+		"field[0,0;0,0;_postfix_;;".._postfix_.."]"}
+	
+	local sConditions = table.concat(aCondTitles, ",")
+	local cond_idx, fs_definition = get_active_subm_definition(_postfix_, "cond", fs_data)
+	tbl[#tbl+1] = "label[0,0.1;Condition type:]"
+	tbl[#tbl+1] = "textlist[0,0.6;8,1.4;cond;"..sConditions..";"..cond_idx.."]"
+	tbl = add_controls_to_table(tbl, _postfix_, fs_data, fs_definition)
+	tbl[#tbl+1] = "button[4,9.4;2,1;_cancel_;cancel]"
+	tbl[#tbl+1] = "button[6,9.4;2,1;_exit_;ok]"
+	return table.concat(tbl)
+end
+
+-- evaluate the row condition
+local function eval_formspec_cond(meta, fs_data, fields, readonly)
+	if readonly then return fs_data end 
+	-- determine condition type
+	local cond = minetest.explode_textlist_event(fields.cond)
+	if cond.type == "CHG" then
+		fs_data["subm"..fields._postfix_.."_cond"] = cond.index
+	end
+	-- prepare data
+	local _, fs_definition = get_active_subm_definition(fields._postfix_, "cond", fs_data)
+	fs_data = field2fs_data(fs_definition, fields, fs_data)
+	local data = get_subm_data(fields._postfix_, fs_definition, fs_data)
+	-- update button for main menu
+	fs_data["cond"..fields._postfix_] = fs_definition.button_label(data)
+	
+	if fields._exit_ == nil then
+		-- update formspec if exit is not pressed
+		meta:set_string("formspec", formspec_cond(fields._postfix_, fs_data))
+	end
+	return fs_data
+end
+	
+
+--
+-- Action formspec
+--
+local function formspec_actn(_postfix_, fs_data)
+	local tbl = {"size[8.2,10]"..
+		default.gui_bg..
+		default.gui_bg_img..
+		default.gui_slots..
+		"field[0,0;0,0;_type_;;actn]"..
+		"field[0,0;0,0;_postfix_;;".._postfix_.."]"}
+	
+	local sActions = table.concat(aActnTitles, ",")
+	local actn_idx, fs_definition = get_active_subm_definition(_postfix_, "actn", fs_data)
+	tbl[#tbl+1] = "label[0,0.1;Action type:]"
+	tbl[#tbl+1] = "textlist[0,0.6;8,1.4;actn;"..sActions..";"..actn_idx.."]"
+	tbl = add_controls_to_table(tbl, _postfix_, fs_data, fs_definition)
+	tbl[#tbl+1] = "button[4,9.4;2,1;_cancel_;cancel]"
+	tbl[#tbl+1] = "button[6,9.4;2,1;_exit_;ok]"
+	return table.concat(tbl)
+end
+
+-- evaluate the row action
+local function eval_formspec_actn(meta, fs_data, fields, readonly)
+	if readonly then return fs_data end 
+	-- determine action type
+	local actn = minetest.explode_textlist_event(fields.actn)
+	if actn.type == "CHG" then
+		fs_data["subm"..fields._postfix_.."_actn"] = actn.index
+	end
+	-- prepare data
+	local _, fs_definition = get_active_subm_definition(fields._postfix_, "actn", fs_data)
+	fs_data = field2fs_data(fs_definition, fields, fs_data)
+	local data = get_subm_data(fields._postfix_, fs_definition, fs_data)
+	-- update button for main menu
+	fs_data["actn"..fields._postfix_] = fs_definition.button_label(data)
+	
+	if fields._exit_ == nil then
+		-- update formspec if exit is not pressed
+		meta:set_string("formspec", formspec_actn(fields._postfix_, fs_data))
+	end
+	if fields._cancel_ then
+		fields._exit_ = true
+	end
+	return fs_data
+end
+
+
+--
+-- Label text formspec
+--
+local function formspec_label(_postfix_, fs_data)
+	local label = fs_data["label".._postfix_] or "<any text>"
+	return "size[6,4]"..
+		default.gui_bg..
+		default.gui_bg_img..
+		default.gui_slots..
+		"field[0,0;0,0;_type_;;label]"..
+		"field[0,0;0,0;_postfix_;;".._postfix_.."]"..
+		"label[0.2,0.3;Label:]"..
+		"field[0.3,1.5;5,1;label;;"..label.."]"..
+		"button[4.5,3;1.5,1;_exit_;ok]"
+end
+
+-- evaluate the row label
+local function eval_formspec_label(meta, fs_data, fields, readonly)
+	if readonly then return fs_data end 
+	fs_data["subml"..fields._postfix_.."_label"] = fields.label
+	if fields._exit_ == nil then
+		meta:set_string("formspec", formspec_label(fields._postfix_, fs_data))
+	end
+	-- set the button label of the main menu based on the given input in the submenu
+	fs_data["label"..fields._postfix_] = fs_data["subml"..fields._postfix_.."_label"]
+	return fs_data
+end
+
+
+--
+-- Operand formspec
+--
+local function formspec_oprnd(_postfix_, fs_data)
+	local oprnd = fs_data["submo".._postfix_.."_oprnd"] or ""
+	return "size[6,4]"..
+		default.gui_bg..
+		default.gui_bg_img..
+		default.gui_slots..
+		"field[0,0;0,0;_type_;;oprnd]"..
+		"field[0,0;0,0;_postfix_;;".._postfix_.."]"..
+		"label[0.2,0.3;Operand:]"..
+		"textlist[0,0.8;5.6,1.4;oprnd;or,and;"..oprnd.."]"..
+		"button[4.5,3;1.5,1;_exit_;ok]"
+end
+
+-- evaluate the row operand
+local function eval_formspec_oprnd(meta, fs_data, fields, readonly)
+	if readonly then return fs_data end 
+	local oprnd = minetest.explode_textlist_event(fields.oprnd)
+	if oprnd.type == "CHG" then
+		fs_data["submo"..fields._postfix_.."_oprnd"] = oprnd.index
+	end
+	if fields._exit_ == nil then
+		meta:set_string("formspec", formspec_oprnd(fields._postfix_, fs_data))
+	end
+	-- set the button label of the main menu based on the given input in the submenu
+	fs_data["oprnd"..fields._postfix_] = fs_data["submo"..fields._postfix_.."_oprnd"] == 1 and "or" or "and"
+	return fs_data
+end
+
+local function formspec_main(state, fs_data, output)
+	local tbl = {"size[15,10;true]"..
+		default.gui_bg..
+		default.gui_bg_img..
+		default.gui_slots..
+		"field[0,0;0,0;_type_;;main]"..
+		"label[0.8,0;label:]label[3.8,0;IF  cond 1:]label[7,0;and/or]label[8.3,0;cond 2:]label[11.7,0;THEN  action:]"}
+		
+	for idx = 1,NUM_RULES do
+		local ypos = idx * 0.8 - 0.4
+		tbl[#tbl+1] = "label[0,"..(0.2+ypos)..";"..idx.."]"
+		tbl[#tbl+1] = "button[0.4,"..ypos..";3,1;label"..idx..";"..(fs_data["label"..idx] or "...").."]"
+		tbl[#tbl+1] = "button[3.5,"..ypos..";3.4,1;cond1"..idx..";"..(fs_data["cond1"..idx] or "...").."]"
+		tbl[#tbl+1] = "button[7,"..  ypos..";1,1;oprnd"..  idx..";"..(fs_data["oprnd"..idx] or "or").."]"
+		tbl[#tbl+1] = "button[8,"..  ypos..";3.4,1;cond2"..idx..";"..(fs_data["cond2"..idx] or "...").."]"
+		tbl[#tbl+1] = "button[11.5,".. ypos..";3.4,1;actna"..idx..";"..(fs_data["actna"..idx] or "...").."]"
+	end
+	tbl[#tbl+1] = "image_button[14,9;1,1;".. tubelib.state_button(state) ..";button;]"
+	tbl[#tbl+1] = "button[10.6,9;1.5,1;state;state]"
+	tbl[#tbl+1] = "button[12.2,9;1.5,1;help;help]"
+	tbl[#tbl+1] = "label[0.2,8.8;"..output.."]"
+	tbl[#tbl+1] = "field[0.4,9.6;4.8,1;cmnd;;<cmnd>]"
+	tbl[#tbl+1] = "button[5,9.3;1,1;ok;OK]"
+	return table.concat(tbl)
+end
+
+local function eval_formspec_main(meta, fs_data, fields, readonly)
+	meta:set_string("fs_old", minetest.serialize(fs_data))
+	for idx = 1,NUM_RULES do
+		-- eval standard inputs
+		if not readonly then
+			fs_data["oprnd"..idx] = fields["oprnd"..idx] or fs_data["oprnd"..idx]
+		end
+		
+		-- eval submenu button events
+		if fields["label"..idx] then
+			meta:set_string("formspec", formspec_label(idx, fs_data))
+		elseif fields["cond1"..idx] then
+			meta:set_string("formspec", formspec_cond("1"..idx, fs_data))
+		elseif fields["cond2"..idx] then
+			meta:set_string("formspec", formspec_cond("2"..idx, fs_data))
+		elseif fields["oprnd"..idx] then
+			meta:set_string("formspec", formspec_oprnd(idx, fs_data))
+		elseif fields["actna"..idx] then
+			meta:set_string("formspec", formspec_actn("a"..idx, fs_data))
+		end
+	end	
+	return fs_data
+end
+
+local function formspec_help(offs)
+	return "size[15,10]"..
+		default.gui_bg..
+		default.gui_bg_img..
+		default.gui_slots..
+		"field[0,0;0,0;_type_;;help]"..
+		"label[0,"..(-offs/50)..";"..sHELP.."]"..
+		--"label[0.2,0;test]"..
+		"scrollbar[13.5,1;0.5,7;vertical;sb_help;"..offs.."]"..
+		"button[13.5,9;1.5,1;close;close]"
+end
+
+local function background(xpos, ypos, val)
+	if val == true then
+		return "box["..(xpos-0.1)..",".. ypos..";3.3,0.4;#008000]"
+	elseif val == false then
+		return "box["..(xpos-0.1)..",".. ypos..";3.3,0.4;#800000]"
+	else
+		return "box["..(xpos-0.1)..",".. ypos..";3.3,0.4;#202020]"
+	end
+end	
+
+local function formspec_state(meta, fs_data)
+	local number = meta:get_string("number")
+	local state = meta:get_int("state")
+	local tbl = {"size[15,10;true]"..
+		default.gui_bg..
+		default.gui_bg_img..
+		default.gui_slots..
+		"field[0,0;0,0;_type_;;state]"..
+		"label[0.8,0;label:]label[3.8,0;IF  cond 1:]label[7,0;and/or]label[8.3,0;cond 2:]label[11.7,0;THEN  action:]"}
+	
+	if state == tubelib.RUNNING and number then
+		local inputs = tubelib.get_data(number, "inputs") or {}
+		local act_gate = tubelib.get_data(number, "act_gate") or {}
+		local timers = tubelib.get_data(number, "timers") or {}
+		local flags = tubelib.get_data(number, "flags") or {}
+		local conds = tubelib.get_data(number, "conds") or {}
+		
+		for idx = 1,NUM_RULES do
+			local ypos = idx * 0.6 + 0.2
+			local s1 = fs_data["cond1"..idx] or "    ...    "
+			local s2 = fs_data["cond2"..idx] or "    ...    "
+			local sa = fs_data["actna"..idx] or "    ...    "
+			if conds[idx] == nil then
+				tbl[#tbl+1] = background(3.7,  ypos, nil)
+				tbl[#tbl+1] = background(8,    ypos, nil)
+			else
+				tbl[#tbl+1] = background(3.7,  ypos, conds[idx] == 1 or conds[idx] == 3)
+				tbl[#tbl+1] = background(8,    ypos, conds[idx] == 2 or conds[idx] == 3)
+			end
+			tbl[#tbl+1] = background(11.5, ypos, act_gate[idx])
+			tbl[#tbl+1] = "label[0,"..  ypos..";"..idx.."]"
+			tbl[#tbl+1] = "label[0.5,"..ypos..";"..(fs_data["label"..idx] or "    ...    ").."]"
+			tbl[#tbl+1] = "label[3.7,"..  ypos..";"..s1.."]"
+			tbl[#tbl+1] = "label[7.2,"..  ypos..";"..(fs_data["oprnd"..idx] or "or").."]"
+			tbl[#tbl+1] = "label[8,"..  ypos..";"..s2.."]"
+			tbl[#tbl+1] = "label[11.5,".. ypos..";"..sa.."]"
+		end
+		
+		tbl[#tbl+1] = "label[10,8.2; Seconds: "..(meta:get_int("runtime") or 1).."]"
+
+		tbl[#tbl+1] = "label[0,7;"..output("Inputs", "i(", ")", inputs).."]"
+		tbl[#tbl+1] = "label[0,7.6;"..output("Timers", "t", "", timers).."]"
+		tbl[#tbl+1] = "label[0,8.2;"..output("Flags", "f", "", flags).."]"
+		
+		tbl[#tbl+1] = "label[0,9;Hint:]"
+		tbl[#tbl+1] = "box[1.3,9;7,0.4;#008000]"
+		tbl[#tbl+1] = "label[1.4,9;condition is true / action was executed]"
+		tbl[#tbl+1] = "box[8.9,9;4,0.4;#800000]"
+		tbl[#tbl+1] = "label[9,9;condition is false]"
+		tbl[#tbl+1] = "box[1.3,9.6;7,0.4;#202020]"
+		tbl[#tbl+1] = "label[1.4,9.6;action was not executed]"
+
+	end
+	
+	tbl[#tbl+1] = "button[13.3,8;1.7,1;update;update]"
+	tbl[#tbl+1] = "button[13.3,9;1.7,1;close;close]"
+	return table.concat(tbl)
+end
+
+local function execute(meta, number, debug)
+	local rt_rules = tubelib.get_data(number, "rt_rules")
+	local inputs = tubelib.get_data(number, "inputs") or {}
+	local act_gate = tubelib.get_data(number, "act_gate") or {}
+	local timers = tubelib.get_data(number, "timers") or {}
+	local flags = tubelib.get_data(number, "flags") or {}
+	local conds = tubelib.get_data(number, "conds") or {}
+	local actions =  {}
+	decrement_timers(timers)
+	for i,item in ipairs(rt_rules) do
+		local c1 = eval_cond(item.cond1, flags, timers, inputs, actions)
+		local c2 = eval_cond(item.cond2, flags, timers, inputs, actions)
+		conds[i] = c1 + c2*2
+		if c1 + c2 >= item.cond_cnt then
+			if act_gate[i] == nil then
+				-- execute action
+				exec_action(item.actn, flags, timers, number)
+				actions[i] = true
+			end
+			act_gate[i] = true
+		else
+			act_gate[i] = nil
+		end
+	end
+	tubelib.set_data(number, "inputs", inputs)
+	tubelib.set_data(number, "act_gate", act_gate)
+	tubelib.set_data(number, "timers", timers)
+	tubelib.set_data(number, "flags", flags)
+	tubelib.set_data(number, "conds", conds)
+end
+
+local function check_rules(pos, elapsed)
+	--local t = minetest.get_us_time()
+	local meta = minetest.get_meta(pos)
+	meta:set_int("runtime", (meta:get_int("runtime") or 1) + 1)
+	local number = meta:get_string("number")
+	local state = meta:get_int("state")
+	if state == tubelib.RUNNING and number then
+		execute(meta, number, debug)
+	end
+	--print("time", minetest.get_us_time() - t)
+	return true
+end
+
+local function switch_state(pos, state, fs_data)
+	local meta = minetest.get_meta(pos)
+	local number = meta:get_string("number")
+	meta:set_int("state", state)
+	meta:set_string("formspec", formspec_main(state, fs_data, sOUTPUT))
+	if state == tubelib.RUNNING then
+		meta:set_string("infotext", "SmartLine Controller "..number..": running")
+		minetest.get_node_timer(pos):start(1)
+	else
+		meta:set_string("infotext", "SmartLine Controller "..number..": stopped")
+		minetest.get_node_timer(pos):stop()
+	end
+end
+
+local function start_controller(pos, number, fs_data)
+	tubelib.set_data(number, "timers",   {})  -- local timers
+	tubelib.set_data(number, "inputs",   {})  -- for rx commands
+	tubelib.set_data(number, "flags",    {})  -- to store flags
+	tubelib.set_data(number, "conds",    {})  -- to store conditions
+	tubelib.set_data(number, "act_gate", {})  -- for action states
+	switch_state(pos, tubelib.RUNNING, fs_data)
+end
+
+local function stop_controller(pos, fs_data)
+	switch_state(pos, tubelib.STOPPED, fs_data)
+end
+
+local function formspec2runtime_rule(number, owner, fs_data)
+	local rt_rules = {}
+	local num2inp = {}
+	for idx = 1,NUM_RULES do
+		-- valid rule?
+		if fs_data["subm1"..idx.."_cond"] and fs_data["subm2"..idx.."_cond"] 
+		and fs_data["subma"..idx.."_actn"] then
+			-- add to list of runtine rules
+			local rule = {
+				cond_cnt = fs_data["oprnd"..idx] == "and" and 2 or 1,
+				cond1 = runtime_data("1"..idx, "cond", fs_data),
+				cond2 = runtime_data("2"..idx, "cond", fs_data),
+				actn  = runtime_data("a"..idx, "actn", fs_data),
+			}
+			rule.actn.owner = owner
+			table.insert(rt_rules, rule)
+		end
+	end 
+	tubelib.set_data(number, "rt_rules", rt_rules)
+end
+
+
+local function get_keys(fs_data)
+	-- collect all keys and remove row information
+	local keys = {}
+	for k,v in pairs(fs_data) do
+		local key = string.sub(k,1,5).."*"..string.sub(k, 7)
+		if type(v) == 'number' then
+			keys[key] = 1  -- default value
+		else
+			keys[key] = "..."  -- default value
+		end
+	end
+	return keys
+end
+
+local function exchange_rules(fs_data, pos1, pos2)
+	-- exchange elem by elem
+	for k,v in pairs(get_keys(fs_data)) do
+		local k1 = string.gsub(k, "*", pos1)
+		local k2 = string.gsub(k, "*", pos2)
+		local temp = fs_data[k1] or v
+		fs_data[k1] = fs_data[k2] or v
+		fs_data[k2] = temp
+	end
+	return fs_data
+end
+
+local function copy_rule(fs_data, pos1, pos2)
+	-- copy elem by elem
+	for k,v in pairs(get_keys(fs_data)) do
+		local k1 = string.gsub(k, "*", pos1)
+		local k2 = string.gsub(k, "*", pos2)
+		fs_data[k2] = fs_data[k1] or v
+	end
+	return fs_data
+end
+
+local function delete_rule(fs_data, pos)
+	for k,v in pairs(get_keys(fs_data)) do
+		local k1 = string.gsub(k, "*", pos)
+		fs_data[k1] = nil
+	end
+	return fs_data
+end
+
+local function edit_command(fs_data, text)
+	local cmnd, pos1, pos2 = text:match('^(%S)%s(%d+)%s(%d+)$')
+	if pos2 == nil then
+		cmnd, pos1 = text:match('^(%S)%s(%d+)$')
+	end
+	if cmnd and pos1 and pos2 then
+		if cmnd == "x" then 
+			exchange_rules(fs_data, pos1, pos2) 
+			return "rows "..pos1.." and "..pos2.." exchanged"
+		end
+		if cmnd == "c" then
+			copy_rule(fs_data, pos1, pos2) 
+			return "row "..pos1.." copied to "..pos2
+		end
+	elseif cmnd == "d" and pos1 then
+		delete_rule(fs_data, pos1)
+		return "row "..pos1.." deleted"
+	end
+	return "Invalid command '"..text.."'"
+end
+
+local function on_receive_fields(pos, formname, fields, player)
+	local meta = minetest.get_meta(pos)
+	local owner = meta:get_string("owner")
+	local state = meta:get_int("state")
+	if not player or not player:is_player() then
+		return
+	end
+	local fs_data = minetest.deserialize(meta:get_string("fs_data")) or {}
+	local output = ""
+	local readonly = player:get_player_name() ~= owner
+	
+	-- FIRST: test if command entered?
+	if fields.ok then
+		if not readonly then	
+			output = edit_command(fs_data, fields.cmnd)
+			stop_controller(pos, fs_data)
+			meta:set_string("formspec", formspec_main(tubelib.STOPPED, fs_data, output))
+			meta:set_string("fs_data", minetest.serialize(fs_data))
+		end
+	-- SECOND: eval none edit events (events based in __type__)?
+	elseif fields.help then
+		meta:set_string("formspec", formspec_help(1))
+	elseif fields.state then
+		meta:set_string("formspec", formspec_state(meta, fs_data))
+	elseif fields.update then
+		meta:set_string("formspec", formspec_state(meta, fs_data))
+	elseif fields._cancel_ then
+		fs_data = minetest.deserialize(meta:get_string("fs_old"))
+		meta:set_string("formspec", formspec_main(state, fs_data, sOUTPUT))
+	elseif fields.close then
+		meta:set_string("formspec", formspec_main(state, fs_data, sOUTPUT))
+	elseif fields.sb_help then
+		local evt = minetest.explode_scrollbar_event(fields.sb_help)
+		if evt.type == "CHG" then
+			meta:set_string("formspec", formspec_help(evt.value))
+		end
+	elseif fields.button then
+		if not readonly then
+			local number = meta:get_string("number")
+			local state = meta:get_int("state")
+			if state == tubelib.RUNNING then
+				stop_controller(pos, fs_data)
+				meta:set_string("formspec", formspec_main(tubelib.STOPPED, fs_data, sOUTPUT))
+			else
+				formspec2runtime_rule(number, owner, fs_data)
+				start_controller(pos, number, fs_data)
+				meta:set_string("formspec", formspec_main(tubelib.RUNNING, fs_data, sOUTPUT))
+			end
+		end
+	-- THIRD: evaluate edit events from sub-menus
+	elseif fields._type_ == "main" then
+		fs_data = eval_formspec_main(meta, fs_data, fields, readonly)
+		meta:set_string("fs_data", minetest.serialize(fs_data))
+	elseif fields._type_ == "label" then
+		fs_data = eval_formspec_label(meta, fs_data, fields, readonly)
+		meta:set_string("fs_data", minetest.serialize(fs_data))
+	elseif fields._type_ == "cond" then
+		fs_data = eval_formspec_cond(meta, fs_data, fields, readonly)
+		meta:set_string("fs_data", minetest.serialize(fs_data))
+	elseif fields._type_ == "oprnd" then
+		fs_data = eval_formspec_oprnd(meta, fs_data, fields, readonly)
+		meta:set_string("fs_data", minetest.serialize(fs_data))
+	elseif fields._type_ == "actn" then
+		fs_data = eval_formspec_actn(meta, fs_data, fields, readonly)
+		meta:set_string("fs_data", minetest.serialize(fs_data))
+	elseif fields._type_ == "help" then
+		meta:set_string("formspec", formspec_main(state, fs_data, sOUTPUT))
+	elseif fields._type_ == "state" then
+		meta:set_string("formspec", formspec_main(state, fs_data, sOUTPUT))
+	end
+	-- FOURTH: back to main menu
+	if fields._exit_ then
+		meta:set_string("formspec", formspec_main(state, fs_data, sOUTPUT))
+--			stop_controller(pos, fs_data)
+--			meta:set_string("fs_data", minetest.serialize(fs_data))
+--		end
+	end
+end
+
+minetest.register_node("smartline:controller", {
+	description = "SmartLine Controller",
+	inventory_image = "smartline_controller_inventory.png",
+	wield_image = "smartline_controller_inventory.png",
+	stack_max = 1,
+	tiles = {
+		-- up, down, right, left, back, front
+		"smartline.png",
+		"smartline.png",
+		"smartline.png",
+		"smartline.png",
+		"smartline.png",
+		"smartline.png^smartline_controller.png",
+	},
+
+	drawtype = "nodebox",
+	node_box = {
+		type = "fixed",
+		fixed = {
+			{ -6/32, -6/32, 14/32,  6/32,  6/32, 16/32},
+		},
+	},
+	
+	after_place_node = function(pos, placer)
+		local meta = minetest.get_meta(pos)
+		local number = tubelib.add_node(pos, "smartline:controller")
+		local fs_data = {}
+		meta:set_string("fs_data", minetest.serialize(fs_data)) 
+		meta:set_string("owner", placer:get_player_name())
+		meta:set_string("number", number)
+		meta:set_int("state", tubelib.STOPPED)
+		meta:set_int("debug", 0)
+		meta:set_string("formspec", formspec_main(tubelib.STOPPED, fs_data, sOUTPUT))
+		meta:set_string("infotext", "SmartLine Controller "..number..": stopped")
+	end,
+
+	on_receive_fields = on_receive_fields,
+	
+	on_dig = function(pos, node, puncher, pointed_thing)
+		if minetest.is_protected(pos, puncher:get_player_name()) then
+			return
+		end
+		
+		minetest.node_dig(pos, node, puncher, pointed_thing)
+		tubelib.remove_node(pos)
+	end,
+	
+	on_timer = check_rules,
+	
+	paramtype = "light",
+	sunlight_propagates = true,
+	paramtype2 = "facedir",
+	groups = {choppy=1, cracky=1, crumbly=1},
+	is_ground_content = false,
+	sounds = default.node_sound_stone_defaults(),
+})
+
+
+minetest.register_craft({
+	output = "smartline:controller",
+	recipe = {
+		{"",         "default:mese_crystal", ""},
+		{"dye:blue", "default:copper_ingot", "tubelib:wlanchip"},
+		{"",         "default:mese_crystal", ""},
+	},
+})
+
+
+local function set_input(meta, payload, val)
+	if payload then 
+		local number = meta:get_string("number")
+		local inputs = tubelib.get_data(number, "inputs")
+		if inputs then
+			inputs[payload] = val
+			tubelib.set_data(number, "inputs", inputs)
+		end
+	end
+end	
+
+tubelib.register_node("smartline:controller", {}, {
+	on_recv_message = function(pos, topic, payload)
+		local meta = minetest.get_meta(pos)
+		if topic == "on" then
+			set_input(meta, payload, topic)
+		elseif topic == "off" then
+			set_input(meta, payload, topic)
+		elseif topic == "state" then
+			local state = meta:get_int("state")
+			return tubelib.statestring(state)
+		else
+			return "unsupported"
+		end
+	end,
+})		
+
+-- List of Controller actions and conditions is dependent on loaded mods.
+-- Therefore, the order of actions and conditions has to be re-assembled each time.
+-- last order from last run is stored as meta data 
+local storage = minetest.get_mod_storage()
+
+local function old_to_new(newTypes, oldTypes)
+	local res = {}
+	if #oldTypes == 0 then
+		return nil
+	end
+	local new = create_kv_list(newTypes)
+	for idx,key in ipairs(oldTypes) do
+		res[idx] = new[key] or 1
+	end
+	return res
+end
+
+local function update_node_database(meta)
+	local aOldCondTypes = minetest.deserialize(meta:get_string("aCondTypes")) or {}
+	local aOldActnTypes = minetest.deserialize(meta:get_string("aActnTypes")) or {}
+
+	local tOld2NewCond = old_to_new(aCondTypes, aOldCondTypes)
+	local tOld2NewActn = old_to_new(aActnTypes, aOldActnTypes)
+
+	meta:set_string("aCondTypes", minetest.serialize(aCondTypes))
+	meta:set_string("aActnTypes", minetest.serialize(aActnTypes))
+	
+	return tOld2NewCond, tOld2NewActn
+end
+
+minetest.register_lbm({
+	label = "[SmartLine] Controller update",
+	name = "smartline:update",
+	nodenames = {"smartline:controller"},
+	run_at_every_load = true,
+	action = function(pos, node)
+		local meta = minetest.get_meta(pos)
+		local fs_data = minetest.deserialize(meta:get_string("fs_data"))
+		
+		local tOld2NewCond, tOld2NewActn = update_node_database(meta)
+		
+		if tOld2NewCond and tOld2NewActn then
+			-- map from old to new indexes
+			for idx = 1,NUM_RULES do
+				fs_data["subm1"..idx.."_cond"] = tOld2NewCond[fs_data["subm1"..idx.."_cond"]]
+				fs_data["subm2"..idx.."_cond"] = tOld2NewCond[fs_data["subm2"..idx.."_cond"]]
+				fs_data["subma"..idx.."_actn"] = tOld2NewActn[fs_data["subma"..idx.."_actn"]]
+			end
+			
+			meta:set_string("fs_data", minetest.serialize(fs_data))
+		end
+		local number = meta:get_string("number")
+		local owner = meta:get_string("owner")
+		formspec2runtime_rule(number, owner, fs_data)
+	end
+})
+

smartline/depends.txt

@@ -0,0 +1,7 @@
+default
+doors
+tubelib
+display_lib?
+font_lib?
+mail?
+

smartline/description.txt

@@ -0,0 +1,2 @@
+SmartLine is a Tubelib extension with small and smart sensors, actors and controllers.
+

smartline/display.lua

@@ -0,0 +1,139 @@
+--[[
+
+	SmartLine
+	=========
+
+	Copyright (C) 2018 Joachim Stolberg
+
+	LGPLv2.1+
+	See LICENSE.txt for more information
+
+	display.lua:
+
+]]--
+
+  
+  
+display_lib.register_display_entity("smartline:entity")
+
+function display_update(pos, objref) 
+	local meta = minetest.get_meta(pos)
+	local text = meta:get_string("text") or ""
+	text = string.gsub(text, "|", " \n")
+	local texture = font_lib.make_multiline_texture(
+		"default", text,
+		120, 120, 9, "top", "#000")
+	objref:set_properties({ textures = {texture},
+							visual_size = {x=0.94, y=0.94} })
+end
+
+
+local lcd_box = {
+	type = "wallmounted",
+	wall_top = {-8/16, 15/32, -8/16, 8/16, 8/16, 8/16}
+}
+
+minetest.register_node("smartline:display", {
+	description = "SmartLine Display",
+	inventory_image = 'smartline_display_inventory.png',
+	tiles = {"smartline_display.png"},
+	drawtype = "nodebox",
+	paramtype = "light",
+	sunlight_propagates = true,
+	paramtype2 = "wallmounted",
+	node_box = lcd_box,
+	selection_box = lcd_box,
+	light_source = 6,
+	
+	display_entities = {
+		["smartline:entity"] = { depth = 0.42,
+			on_display_update = display_update},
+	},
+
+	after_place_node = function(pos, placer)
+		local number = tubelib.add_node(pos, "smartline:display")
+		local meta = minetest.get_meta(pos)
+		meta:set_string("number", number)
+		meta:set_string("text", " \n \nMinetest\nSmartLine Tools\n \nDisplay\nNumber: "..number)
+		meta:set_int("startscreen", 1)
+		display_lib.update_entities(pos)
+	end,
+
+	on_place = display_lib.on_place,
+	on_construct = display_lib.on_construct,
+	on_destruct = display_lib.on_destruct,
+	on_rotate = display_lib.on_rotate,
+	groups = {cracky=2, crumbly=2},
+	is_ground_content = false,
+	sounds = default.node_sound_glass_defaults(),
+})
+
+
+minetest.register_craft({
+	output = "smartline:display",
+	recipe = {
+		{"", "", ""},
+		{"default:glass", "dye:green", "tubelib:wlanchip"},
+		{"", "default:copper_ingot", ""},
+	},
+})
+
+local function add_line(meta, payload)
+	local text = meta:get_string("text")
+	local rows
+	if meta:get_int("startscreen") == 1 then
+		rows = {}
+		meta:set_int("startscreen", 0)
+	else
+		rows = string.split(text, "|")
+	end
+	if #rows > 8 then
+		table.remove(rows, 1)
+	end
+	table.insert(rows, payload)
+	text = table.concat(rows, "|")
+	meta:set_string("text", text)
+end
+
+local function write_row(meta, payload)
+	local text = meta:get_string("text")
+	if type(payload) == "table" then
+		local row = tonumber(payload.row) or 1
+		local str = payload.str or "oops"
+		local rows
+		if meta:get_int("startscreen") == 1 then
+			rows = {}
+			meta:set_int("startscreen", 0)
+		else
+			rows = string.split(text, "|")
+		end
+		if #rows < 9 then
+			for i = #rows, 9 do
+				table.insert(rows, " ")
+			end
+		end
+		rows[row] = str
+		text = table.concat(rows, "|")
+		meta:set_string("text", text)
+	end
+end
+
+tubelib.register_node("smartline:display", {}, {
+	on_recv_message = function(pos, topic, payload)
+		local node = minetest.get_node(pos)
+		if topic == "text" then  -- add one line and scroll if necessary
+			local meta = minetest.get_meta(pos)
+			add_line(meta, payload)
+			display_lib.update_entities(pos)
+		elseif topic == "row" then  -- overwrite the given row
+			local meta = minetest.get_meta(pos)
+			write_row(meta, payload)
+			display_lib.update_entities(pos)
+		elseif topic == "clear" then  -- clear the screen
+			local meta = minetest.get_meta(pos)
+			meta:set_string("text", "")
+			display_lib.update_entities(pos)
+		end
+	end,
+})		
+

smartline/init.lua

@@ -0,0 +1,29 @@
+--[[
+
+	SmartLine
+	=========
+	
+	Copyright (C) 2018 Joachim Stolberg
+
+	LGPLv2.1+
+	See LICENSE.txt for more information
+
+	History:
+	2018-01-01  v0.01  first version
+	2018-01-26  v0.02  timer and sequencer added
+	2018-02-01  v0.03  further commands, hints and cancel button aded
+
+]]--
+
+if minetest.get_modpath("display_lib") and display_lib ~= nil and
+				minetest.get_modpath("font_lib") and font_lib ~= nil then
+	dofile(minetest.get_modpath("smartline") .. "/playerdetector.lua")
+end
+dofile(minetest.get_modpath("smartline") .. "/button.lua")
+dofile(minetest.get_modpath("smartline") .. "/signaltower.lua")
+dofile(minetest.get_modpath("smartline") .. "/display.lua")
+dofile(minetest.get_modpath("smartline") .. "/sequencer.lua")
+dofile(minetest.get_modpath("smartline") .. "/timer.lua")
+dofile(minetest.get_modpath("smartline") .. "/repeater.lua")
+dofile(minetest.get_modpath("smartline") .. "/controller.lua")
+dofile(minetest.get_modpath("smartline") .. "/commands.lua")

smartline/mod.conf

@@ -0,0 +1 @@
+name=smartline

smartline/playerdetector.lua

@@ -0,0 +1,224 @@
+--[[
+
+	SmartLine
+	=========
+
+	Copyright (C) 2018 Joachim Stolberg
+
+	LGPLv2.1+
+	See LICENSE.txt for more information
+
+	playerdetector.lua:
+	
+]]--
+
+local function switch_on(pos)
+	local meta = minetest.get_meta(pos)
+	local node = minetest.get_node(pos)
+	node.name = "smartline:playerdetector_active"
+	minetest.swap_node(pos, node)
+	local number = meta:get_string("number")
+	local numbers = meta:get_string("numbers")
+	local owner = meta:get_string("owner")
+	tubelib.send_message(numbers, owner, nil, "on", number)
+end
+
+local function switch_off(pos)
+	local meta = minetest.get_meta(pos)
+	local node = minetest.get_node(pos)
+	node.name = "smartline:playerdetector"
+	minetest.swap_node(pos, node)
+	local number = meta:get_string("number")
+	local numbers = meta:get_string("numbers")
+	local owner = meta:get_string("owner")
+	tubelib.send_message(numbers, owner, nil, "off", number)
+end
+
+local function scan_for_player(pos)
+	local meta = minetest.get_meta(pos)
+	local names = meta:get_string("names") or ""
+	for _, object in pairs(minetest.get_objects_inside_radius(pos, 4)) do
+		if object:is_player() then
+			if names == "" then 
+				meta:set_string("player_name", object:get_player_name())
+				return true 
+			end
+			for _,name in ipairs(string.split(names, " ")) do
+				if object:get_player_name() == name then 
+					meta:set_string("player_name", name)
+					return true 
+				end
+			end
+		end
+	end
+	meta:set_string("player_name", nil)
+	return false
+end
+
+local function formspec_help()
+	return "size[10,9]"..
+		default.gui_bg..
+		default.gui_bg_img..
+		default.gui_slots..
+		"label[3,0;Player Detector Help]"..
+		"label[0,1;Input the number(s) of the receiving node(s).\n"..
+		"Separate numbers via blanks, like '0123 0234'.\n\n"..
+		"Input the player name(s) separated by blanks,\nor empty for all players.]"..
+		"button_exit[4,8;2,1;exit;close]"
+end
+
+
+local function formspec(numbers, names)
+	return "size[8,5]"..
+		default.gui_bg..
+		default.gui_bg_img..
+		default.gui_slots..
+		"label[2,0;Player Detector]"..
+		"field[0.3,1;8,1;numbers;Receiver node numbers:;"..numbers.."]" ..
+		"field[0.3,2.5;8,1;names;Player name(s):;"..names.."]" ..
+		"button_exit[5,3.5;2,1;exit;Save]"..
+		"button[1,3.5;1,1;help;help]"
+end
+
+local function on_receive_fields(pos, formname, fields, player)
+	local meta = minetest.get_meta(pos)
+	local owner = meta:get_string("owner")
+	if player:get_player_name() == owner then
+		if fields.exit == "Save" then
+			if tubelib.check_numbers(fields.numbers) then
+				meta:set_string("numbers", fields.numbers)
+			end
+			meta:set_string("names", fields.names)
+			meta:set_string("formspec", formspec(fields.numbers, fields.names))
+		elseif fields.help ~= nil then
+			meta:set_string("formspec", formspec_help())
+		elseif fields.exit == "close" then
+			local numbers = meta:get_string("numbers")
+			local names = meta:get_string("names")
+			meta:set_string("formspec", formspec(numbers, names))
+		end
+	end
+end
+
+minetest.register_node("smartline:playerdetector", {
+	description = "SmartLine Player Detector",
+	inventory_image = "smartline_detector_inventory.png",
+	tiles = {
+		-- up, down, right, left, back, front
+		"smartline.png",
+		"smartline.png",
+		"smartline.png",
+		"smartline.png",
+		"smartline.png",
+		"smartline.png^smartline_detector.png",
+	},
+
+	drawtype = "nodebox",
+	node_box = {
+		type = "fixed",
+		fixed = {
+			{ -6/32, -6/32, 14/32,  6/32,  6/32, 16/32},
+		},
+	},
+	after_place_node = function(pos, placer)
+		local number = tubelib.add_node(pos, "smartline:playerdetector")
+		local meta = minetest.get_meta(pos)
+		meta:set_string("number", number)
+		local numbers = meta:get_string("numbers") or ""
+		local names = meta:get_string("names") or ""
+		meta:set_string("formspec", formspec(numbers, names))
+		meta:set_string("infotext", "SmartLine Player Detector "..number)
+		meta:set_string("owner", placer:get_player_name())
+		minetest.get_node_timer(pos):start(1)
+	end,
+
+	on_receive_fields = on_receive_fields,
+	
+	after_dig_node = function(pos)
+		tubelib.remove_node(pos)
+	end,
+	
+	on_timer = function (pos, elapsed)
+		if scan_for_player(pos) then
+			switch_on(pos)
+			minetest.get_node_timer(pos):start(1)
+			return false
+		end
+		return true
+	end,
+
+	paramtype = "light",
+	sunlight_propagates = true,
+	paramtype2 = "facedir",
+	groups = {cracky=2, crumbly=2},
+	is_ground_content = false,
+	sounds = default.node_sound_metal_defaults(),
+})
+
+minetest.register_node("smartline:playerdetector_active", {
+	description = "SmartLine Player Detector",
+	tiles = {
+		-- up, down, right, left, back, front
+		"smartline.png",
+		"smartline.png",
+		"smartline.png",
+		"smartline.png",
+		"smartline.png",
+		"smartline.png^smartline_detector_active.png",
+	},
+
+	drawtype = "nodebox",
+	node_box = {
+		type = "fixed",
+		fixed = {
+			{ -6/32, -6/32, 14/32,  6/32,  6/32, 16/32},
+		},
+	},
+	
+	on_receive_fields = on_receive_fields,
+	
+	after_dig_node = function(pos)
+		tubelib.remove_node(pos)
+	end,
+
+	on_timer = function (pos, elapsed)
+		if not scan_for_player(pos) then
+			switch_off(pos)
+			minetest.get_node_timer(pos):start(1)
+			return false
+		end
+		return true
+	end,
+	paramtype = "light",
+	sunlight_propagates = true,
+	paramtype2 = "facedir",
+	groups = {cracky=2, crumbly=2, not_in_creative_inventory=1},
+	is_ground_content = false,
+	sounds = default.node_sound_metal_defaults(),
+	drop = "smartline:playerdetector"
+})
+
+minetest.register_craft({
+	output = "smartline:playerdetector",
+	recipe = {
+		{"", "default:copper_ingot", ""},
+		{"dye:blue", "default:copper_ingot", "tubelib:wlanchip"},
+		{"", "", ""},
+	},
+})
+
+tubelib.register_node("smartline:playerdetector", {"smartline:playerdetector_active"}, {
+	on_recv_message = function(pos, topic, payload)
+		if topic == "set_numbers" then
+			local meta = minetest.get_meta(pos)
+			meta:set_string("numbers", payload)
+			local names = meta:get_string("names") or ""
+			meta:set_string("formspec", formspec(payload, names))
+			return true
+		elseif topic == "name" then
+			local meta = minetest.get_meta(pos)
+			return meta:get_string("player_name")
+		end
+	end,
+})		
+

smartline/repeater.lua

@@ -0,0 +1,127 @@
+--[[
+
+	SmartLine
+	=========
+
+	Copyright (C) 2018 Joachim Stolberg
+
+	LGPLv2.1+
+	See LICENSE.txt for more information
+
+	repeater.lua:
+	Derived from Tubelib repeater
+
+]]--
+
+local OVER_LOAD_MAX = 5
+
+local function formspec(meta)
+	local numbers = meta:get_string("numbers")
+	return "size[7,5]"..
+		"field[0.5,2;6,1;number;Destination node numbers;"..numbers.."]" ..
+		"button_exit[1,3;2,1;exit;Save]"
+end	
+
+minetest.register_node("smartline:repeater", {
+	description = "SmartLine Repeater",
+	inventory_image = "smartline_repeater_inventory.png",
+	tiles = {
+		-- up, down, right, left, back, front
+		"smartline.png",
+		"smartline.png",
+		"smartline.png",
+		"smartline.png",
+		"smartline.png",
+		"smartline.png^smartline_repeater.png",
+	},
+
+	drawtype = "nodebox",
+	node_box = {
+		type = "fixed",
+		fixed = {
+			{ -6/32, -6/32, 14/32,  6/32,  6/32, 16/32},
+		},
+	},
+
+	after_place_node = function(pos, placer)
+		local meta = minetest.get_meta(pos)
+		local own_number = tubelib.add_node(pos, "smartline:repeater")
+		meta:set_string("own_number", own_number)
+		meta:set_string("formspec", formspec(meta))
+		meta:set_string("infotext", "SmartLine Repeater "..own_number..": not connected")
+		meta:set_string("owner", placer:get_player_name())
+		meta:set_int("overload_cnt", 0)
+		minetest.get_node_timer(pos):start(1)
+	end,
+
+	on_receive_fields = function(pos, formname, fields, player)
+		local meta = minetest.get_meta(pos)
+		local owner = meta:get_string("owner")
+		if owner ~= player:get_player_name() then
+			return
+		end
+		
+		if tubelib.check_numbers(fields.number) then
+			meta:set_string("numbers", fields.number)
+			local own_number = meta:get_string("own_number")
+			meta:set_string("infotext", "SmartLine Repeater "..own_number..": connected with "..fields.number)
+			meta:set_string("formspec", formspec(meta))
+		end
+		
+		local timer = minetest.get_node_timer(pos)
+		if not timer:is_started() then
+			timer:start(1)
+		end
+	end,
+	
+	on_timer = function(pos,elapsed)
+		local meta = minetest.get_meta(pos)
+		meta:set_int("overload_cnt", 0)
+		return true
+	end,
+	
+	after_dig_node = function(pos)
+		tubelib.remove_node(pos)
+	end,
+
+	paramtype = "light",
+	sunlight_propagates = true,
+	paramtype2 = "facedir",
+	groups = {choppy=2, cracky=2, crumbly=2},
+	is_ground_content = false,
+	sounds = default.node_sound_stone_defaults(),
+})
+
+
+minetest.register_craft({
+	output = "smartline:repeater",
+	recipe = {
+		{"default:copper_ingot", "", "default:copper_ingot"},
+		{"tubelib:wlanchip", "", "tubelib:wlanchip"},
+		{"", "", ""},
+	},
+})
+
+tubelib.register_node("smartline:repeater", {}, {
+	on_recv_message = function(pos, topic, payload)
+		local meta = minetest.get_meta(pos)
+		local owner = meta:get_string("owner")
+		local numbers = meta:get_string("numbers")
+		local overload_cnt = meta:get_int("overload_cnt") + 1
+		meta:set_int("overload_cnt", overload_cnt)
+		if overload_cnt > OVER_LOAD_MAX then
+			local own_number = meta:get_string("own_number")
+			meta:set_string("infotext", "SmartLine Repeater "..own_number..": fault (overloaded)")
+			minetest.get_node_timer(pos):stop()
+			return false
+		elseif topic == "set_numbers" then
+			local own_number = meta:get_string("own_number")
+			meta:set_string("infotext", "SmartLine Repeater "..own_number..": connected with "..payload)
+			meta:set_string("numbers", payload)
+			meta:set_string("formspec", formspec(meta))
+			return true
+		else
+			return tubelib.send_message(numbers, owner, nil, topic, payload)
+		end
+	end,
+})		

smartline/sequencer.lua

@@ -0,0 +1,281 @@
+--[[
+
+	SmartLine
+	=========
+	
+	Copyright (C) 2018 Joachim Stolberg
+
+	LGPLv2.1+
+	See LICENSE.txt for more information
+
+	sequencer.lua:
+	Derived from Tubelib sequencer
+	
+]]--
+
+local RUNNING_STATE = 1
+local STOP_STATE = 0
+local NUM_SLOTS = 8
+
+local sHELP = [[label[0,0;SmartLine Sequencer Help
+
+Define a sequence of commands to control other machines.
+Numbers(s) are the node numbers, the command shall sent to.
+The commands 'on'/'off' are used for machines and other nodes.
+Offset is the time to the next line in seconds (0..999).
+If endless is set, the Sequencer restarts again and again.
+The command '  ' does nothing, only consuming the offset time.
+]
+]]
+
+
+local sAction = ",on,off"
+local kvAction = {[""]=1, ["on"]=2, ["off"]=3}
+local tAction = {nil, "on", "off"}
+
+local function formspec(state, rules, endless)
+	endless = endless == 1 and "true" or "false"
+	local tbl = {"size[8,9.2]"..
+		default.gui_bg..
+		default.gui_bg_img..
+		default.gui_slots..
+		"label[0,0;Number(s)]label[2.1,0;Command]label[6.4,0;Offset/s]"}
+		
+	for idx, rule in ipairs(rules) do
+		tbl[#tbl+1] = "field[0.2,"..(-0.2+idx)..";2,1;num"..idx..";;"..(rule.num or "").."]"
+		tbl[#tbl+1] = "dropdown[2,"..(-0.4+idx)..";3.9,1;act"..idx..";"..sAction..";"..(rule.act or "").."]"
+		tbl[#tbl+1] = "field[6.2,"..(-0.2+idx)..";2,1;offs"..idx..";;"..(rule.offs or "").."]"
+	end
+	tbl[#tbl+1] = "checkbox[0,8.5;endless;Run endless;"..endless.."]"
+	tbl[#tbl+1] = "button[4.5,8.5;1.5,1;help;help]"
+	tbl[#tbl+1] = "image_button[6.5,8.5;1,1;".. tubelib.state_button(state) ..";button;]"
+	
+	return table.concat(tbl)
+end
+
+local function formspec_help()
+	return "size[13,10]"..
+		default.gui_bg..
+		default.gui_bg_img..
+		default.gui_slots..
+		"field[0,0;0,0;_type_;;help]"..
+		sHELP..
+		--"label[0.2,0;test]"..
+		"button[11.5,9;1.5,1;close;close]"
+end
+
+local function stop_the_sequencer(pos)
+	local node = minetest.get_node(pos)
+	local meta = minetest.get_meta(pos)
+	local number = meta:get_string("number")
+	meta:set_int("running", STOP_STATE)
+	meta:set_string("infotext", "Tubelib Sequencer "..number..": stopped")
+	local rules = minetest.deserialize(meta:get_string("rules"))
+	local endless = meta:get_int("endless") or 0
+	meta:set_string("formspec", formspec(tubelib.STOPPED, rules, endless))
+	minetest.get_node_timer(pos):stop()
+	return false
+end
+
+local function get_next_slot(idx, rules, endless)
+	idx = idx + 1
+	if idx <= #rules and rules[idx].offs ~= "" and rules[idx].num ~= "" then
+		return idx
+	elseif endless == 1 then
+		return 1
+	end
+	return nil
+end
+
+local function restart_timer(pos, time)
+	local timer = minetest.get_node_timer(pos)
+	if timer:is_started() then
+		timer:stop()
+	end
+	if type(time) == "number" then
+		timer:start(time)
+	end
+end	
+
+local function check_rules(pos, elapsed)
+	local meta = minetest.get_meta(pos)
+	local rules = minetest.deserialize(meta:get_string("rules"))
+	if rules then
+		local running = meta:get_int("running")
+		local index = meta:get_int("index") or 1
+		local number = meta:get_string("number")
+		local endless = meta:get_int("endless") or 0
+		local placer_name = meta:get_string("placer_name")
+		while true do -- process all rules as long as offs == 0
+			local rule = rules[index]
+			local offs = rules[index].offs
+			tubelib.send_message(rule.num, placer_name, nil, tAction[rule.act], number)
+			index = get_next_slot(index, rules, endless)
+			if index ~= nil and offs ~= nil and running == 1 then
+				-- after the last rule a pause with 2 or more sec is required
+				if index == 1 and offs < 2 then
+					offs = 2
+				end
+				meta:set_string("infotext", "Tubelib Sequencer "..number..": running ("..index.."/"..NUM_SLOTS..")")
+				meta:set_int("index", index)
+				if offs > 0 then
+					minetest.after(0, restart_timer, pos, offs)
+					return false
+				end
+			else
+				return stop_the_sequencer(pos)
+			end
+		end
+	end
+	return false
+end
+
+local function start_the_sequencer(pos)
+	local node = minetest.get_node(pos)
+	local meta = minetest.get_meta(pos)
+	local number = meta:get_string("number")
+	meta:set_int("running", 1)
+	meta:set_int("index", 1)
+	meta:set_string("infotext", "SmartLine Sequencer "..number..": running (1/"..NUM_SLOTS..")")
+	local rules = minetest.deserialize(meta:get_string("rules"))
+	local endless = meta:get_int("endless") or 0
+	meta:set_string("formspec", formspec(tubelib.RUNNING, rules, endless))
+	minetest.get_node_timer(pos):start(0.1)
+	return false
+end
+
+local function 	on_receive_fields(pos, formname, fields, player)
+	local meta = minetest.get_meta(pos)
+	local running = meta:get_int("running")
+	if minetest.is_protected(pos, player:get_player_name()) then
+		return
+	end
+	if fields.help ~= nil then
+		meta:set_string("formspec", formspec_help())
+		return
+	end
+	
+	local endless = meta:get_int("endless") or 0
+	if fields.endless ~= nil then
+		endless = fields.endless == "true" and 1 or 0
+		meta:set_int("index", 1)
+	end
+	meta:set_int("endless", endless)
+	
+	local rules = minetest.deserialize(meta:get_string("rules"))
+	if fields.exit ~= nil then
+		meta:set_string("formspec", formspec(tubelib.state(running), rules, endless))
+		return
+	end
+
+	for idx = 1,NUM_SLOTS do
+		if fields["offs"..idx] ~= nil then
+			rules[idx].offs = tonumber(fields["offs"..idx]) or ""
+		end
+		if fields["num"..idx] ~= nil and tubelib.check_numbers(fields["num"..idx]) then
+			rules[idx].num = fields["num"..idx]
+		end
+		if fields["act"..idx] ~= nil then
+			rules[idx].act = kvAction[fields["act"..idx]]
+		end
+	end
+	meta:set_string("rules", minetest.serialize(rules))
+
+	if fields.button ~= nil then
+		if running > STOP_STATE then
+			stop_the_sequencer(pos)
+		else
+			start_the_sequencer(pos)
+		end
+	elseif fields.num1 ~= nil then  -- any other change?
+		stop_the_sequencer(pos)
+	else
+		local endless = meta:get_int("endless") or 0
+		meta:set_string("formspec", formspec(tubelib.state(running), rules, endless))
+	end
+end
+
+minetest.register_node("smartline:sequencer", {
+	description = "SmartLine Sequencer",
+	inventory_image = "smartline_sequencer_inventory.png",
+	wield_image = "smartline_sequencer_inventory.png",
+	stack_max = 1,
+	tiles = {
+		-- up, down, right, left, back, front
+		"smartline.png",
+		"smartline.png",
+		"smartline.png",
+		"smartline.png",
+		"smartline.png",
+		"smartline.png^smartline_sequencer.png",
+	},
+	
+	drawtype = "nodebox",
+	node_box = {
+		type = "fixed",
+		fixed = {
+			{ -6/32, -6/32, 14/32,  6/32,  6/32, 16/32},
+		},
+	},
+	after_place_node = function(pos, placer)
+		local meta = minetest.get_meta(pos)
+		local number = tubelib.add_node(pos, "smartline:sequencer")
+		local rules = {}
+		for idx = 1,NUM_SLOTS do
+			rules[idx] = {offs = "", num = "", act = 1}
+		end
+		meta:set_string("placer_name", placer:get_player_name())
+		meta:set_string("rules", minetest.serialize(rules))
+		meta:set_string("number", number)
+		meta:set_int("index", 1)
+		meta:set_int("endless", 0)
+		meta:get_int("running", STOP_STATE)
+		meta:set_string("formspec", formspec(tubelib.STOPPED, rules, 0))
+	end,
+
+	on_receive_fields = on_receive_fields,
+	
+	on_dig = function(pos, node, puncher, pointed_thing)
+		if minetest.is_protected(pos, puncher:get_player_name()) then
+			return
+		end
+		local meta = minetest.get_meta(pos)
+		local running = meta:get_int("running")
+		if running ~= 1 then
+			minetest.node_dig(pos, node, puncher, pointed_thing)
+			tubelib.remove_node(pos)
+		end
+	end,
+	
+	on_timer = check_rules,
+	
+	paramtype = "light",
+	sunlight_propagates = true,
+	paramtype2 = "facedir",
+	groups = {choppy=2, cracky=2, crumbly=2},
+	is_ground_content = false,
+	sounds = default.node_sound_stone_defaults(),
+})
+
+
+minetest.register_craft({
+	output = "smartline:sequencer",
+	recipe = {
+		{"",         "default:mese_crystal", ""},
+		{"dye:blue", "default:copper_ingot", "tubelib:wlanchip"},
+		{"",         "", ""},
+	},
+})
+
+tubelib.register_node("smartline:sequencer", {}, {
+	on_recv_message = function(pos, topic, payload)
+		local node = minetest.get_node(pos)
+		if topic == "on" then
+			start_the_sequencer(pos)
+		elseif topic == "off" then
+			-- do not stop immediately
+			local meta = minetest.get_meta(pos)
+			meta:set_int("endless", 0)
+		end
+	end,
+})		

smartline/signaltower.lua

@@ -0,0 +1,133 @@
+--[[
+
+	SmartLine
+	=========
+
+	Copyright (C) 2018 Joachim Stolberg
+
+	LGPLv2.1+
+	See LICENSE.txt for more information
+
+	signaltower.lua:
+
+]]--
+
+
+local function switch_on(pos, node, color)
+	local meta = minetest.get_meta(pos)
+	meta:set_string("state", color)
+	node.name = "smartline:signaltower_"..color
+	minetest.swap_node(pos, node)
+end	
+
+local function switch_off(pos, node)
+	local meta = minetest.get_meta(pos)
+	meta:set_string("state", "off")
+	node.name = "smartline:signaltower"
+	minetest.swap_node(pos, node)
+end	
+
+minetest.register_node("smartline:signaltower", {
+	description = "SmartLine Signal Tower",
+	tiles = {
+		'smartline_signaltower_top.png',
+		'smartline_signaltower_top.png',
+		'smartline_signaltower.png',
+	},
+
+	drawtype = "nodebox",
+	node_box = {
+		type = "fixed",
+		fixed = {
+			{ -5/32, -16/32, -5/32,  5/32,  16/32, 5/32},
+		},
+	},
+	
+	after_place_node = function(pos, placer)
+		local number = tubelib.add_node(pos, "smartline:signaltower")
+		local meta = minetest.get_meta(pos)
+		meta:set_string("state", "off")
+		meta:set_string("infotext", "SmartLine Signal Tower "..number)
+	end,
+
+	on_rightclick = function(pos, node, clicker)
+		if not minetest.is_protected(pos, clicker:get_player_name()) then
+			switch_on(pos, node, "green")
+		end
+	end,
+
+	after_dig_node = function(pos)
+		tubelib.remove_node(pos)
+	end,
+
+	paramtype = "light",
+	light_source = 0,	
+	sunlight_propagates = true,
+	paramtype2 = "facedir",
+	groups = {cracky=2, crumbly=2},
+	is_ground_content = false,
+	sounds = default.node_sound_glass_defaults(),
+})
+
+for _,color in ipairs({"green", "amber", "red"}) do
+	minetest.register_node("smartline:signaltower_"..color, {
+		description = "SmartLine Signal Tower",
+		tiles = {
+			'smartline_signaltower_top.png',
+			'smartline_signaltower_top.png',
+			'smartline_signaltower_'..color..'.png',
+		},
+
+		drawtype = "nodebox",
+		node_box = {
+			type = "fixed",
+			fixed = {
+				{ -5/32, -16/32, -5/32,  5/32,  16/32, 5/32},
+			},
+		},
+		on_rightclick = function(pos, node, clicker)
+			if not minetest.is_protected(pos, clicker:get_player_name()) then
+				switch_off(pos, node)
+			end
+		end,
+
+		paramtype = "light",
+		light_source = LIGHT_MAX,	
+		sunlight_propagates = true,
+		paramtype2 = "facedir",
+		groups = {crumbly=0, not_in_creative_inventory=1},
+		is_ground_content = false,
+		sounds = default.node_sound_glass_defaults(),
+		drop = "smartline:signaltower",
+	})
+end
+
+minetest.register_craft({
+	output = "smartline:signaltower",
+	recipe = {
+		{"dye:red",    "default:copper_ingot", ""},
+		{"dye:orange", "default:glass", ""},
+		{"dye:green",  "tubelib:wlanchip", ""},
+	},
+})
+
+tubelib.register_node("smartline:signaltower", {
+	"smartline:signaltower_green", 
+	"smartline:signaltower_amber", 
+	"smartline:signaltower_red"}, {
+	on_recv_message = function(pos, topic, payload)
+		local node = minetest.get_node(pos)
+		if topic == "green" then
+			switch_on(pos, node, "green")
+		elseif topic == "amber" then
+			switch_on(pos, node, "amber")
+		elseif topic == "red" then
+			switch_on(pos, node, "red")
+		elseif topic == "off" then
+			switch_off(pos, node)
+		elseif topic == "state" then
+			local meta = minetest.get_meta(pos)
+			return meta:get_string("state")
+		end
+	end,
+})		

smartline/timer.lua

@@ -0,0 +1,245 @@
+--[[
+
+	SmartLine
+	=========
+	
+	Copyright (C) 2018 Joachim Stolberg
+
+	LGPLv2.1+
+	See LICENSE.txt for more information
+
+	timer.lua:
+	Derived from Tubelib timer
+	
+]]--
+
+local CYCLE_TIME = 8
+
+local sHELP = [[label[0,0;SmartLine Timer Help
+
+tbd
+]
+]]
+
+
+local tTime = {
+	["00:00"] = 1, ["02:00"] = 2, ["04:00"] = 3, 
+	["06:00"] = 4, ["08:00"] = 5, ["10:00"] = 6,
+	["12:00"] = 7, ["14:00"] = 8, ["16:00"] = 9, 
+	["18:00"] =10, ["20:00"] =11, ["22:00"] =12,
+}
+
+local sTime = "00:00,02:00,04:00,06:00,08:00,10:00,12:00,14:00,16:00,18:00,20:00,22:00"
+
+local tAction = {
+	[""] = 1,
+	["on"] = 2,
+	["off"] = 3,
+}
+
+local sAction = ",on,off"
+
+local function formspec(events, numbers, actions)
+	return "size[8,8]"..
+		default.gui_bg..
+		default.gui_bg_img..
+		default.gui_slots..
+			
+		"label[0,0;Time]label[2.3,0;Number(s)]label[4.5,0;Command]"..
+		"dropdown[0,1;2,1;e1;"..sTime..";"..events[1].."]".. 
+		"field[2.3,1.2;2,1;n1;;"..numbers[1].."]" ..
+		"dropdown[4.5,1;3,1;a1;"..sAction..";"..tAction[actions[1]].."]".. 
+		
+		"dropdown[0,2;2,1;e2;"..sTime..";"..events[2].."]".. 
+		"field[2.3,2.2;2,1;n2;;"..numbers[2].."]" ..
+		"dropdown[4.5,2;3,1;a2;"..sAction..";"..tAction[actions[2]].."]".. 
+		
+		"dropdown[0,3;2,1;e3;"..sTime..";"..events[3].."]".. 
+		"field[2.3,3.2;2,1;n3;;"..numbers[3].."]" ..
+		"dropdown[4.5,3;3,1;a3;"..sAction..";"..tAction[actions[3]].."]".. 
+		
+		"dropdown[0,4;2,1;e4;"..sTime..";"..events[4].."]".. 
+		"field[2.3,4.2;2,1;n4;;"..numbers[4].."]" ..
+		"dropdown[4.5,4;3,1;a4;"..sAction..";"..tAction[actions[4]].."]".. 
+		
+		"dropdown[0,5;2,1;e5;"..sTime..";"..events[5].."]".. 
+		"field[2.3,5.2;2,1;n5;;"..numbers[5].."]" ..
+		"dropdown[4.5,5;3,1;a5;"..sAction..";"..tAction[actions[5]].."]".. 
+		
+		"dropdown[0,6;2,1;e6;"..sTime..";"..events[6].."]".. 
+		"field[2.3,6.2;2,1;n6;;"..numbers[6].."]" ..
+		"dropdown[4.5,6;3,1;a6;"..sAction..";"..tAction[actions[6]].."]".. 
+		
+		"button[4.5,7;1.5,1;help;help]"..
+		"button_exit[6.5,7;1.5,1;exit;close]"
+end
+
+local function formspec_help()
+	return "size[13,10]"..
+		default.gui_bg..
+		default.gui_bg_img..
+		default.gui_slots..
+		"field[0,0;0,0;_type_;;help]"..
+		sHELP..
+		--"label[0.2,0;test]"..
+		"button[11.5,9;1.5,1;close;close]"
+end
+
+local function check_rules(pos,elapsed)
+	local hour = math.floor(minetest.get_timeofday() * 24)
+	local meta = minetest.get_meta(pos)
+	local events = minetest.deserialize(meta:get_string("events"))
+	local numbers = minetest.deserialize(meta:get_string("numbers"))
+	local actions = minetest.deserialize(meta:get_string("actions"))
+	local done = minetest.deserialize(meta:get_string("done"))
+	local placer_name = meta:get_string("placer_name")
+	local own_num = meta:get_string("own_num")
+	
+	-- check all rules
+	for idx,act in ipairs(actions) do
+		if act ~= "" and numbers[idx] ~= "" then
+			local hr = (events[idx] - 1) * 2
+			if hour == hr and done[idx] == false then
+				tubelib.send_message(numbers[idx], placer_name, nil, act, own_num)
+				done[idx] = true
+			end
+		end
+	end
+	
+	-- prepare for the next day
+	if hour == 23 then
+		done = {false,false,false,false,false,false}
+	end
+	meta:set_string("done",  minetest.serialize(done))
+	meta:set_string("infotext","SmartLine Timer ("..own_num..")"..hour..":00")
+	return true
+end
+
+
+minetest.register_node("smartline:timer", {
+	description = "SmartLine Timer",
+	inventory_image = "smartline_timer_inventory.png",
+	wield_image = "smartline_timer_inventory.png",
+	stack_max = 1,
+	tiles = {
+		-- up, down, right, left, back, front
+		"smartline.png",
+		"smartline.png",
+		"smartline.png",
+		"smartline.png",
+		"smartline.png",
+		"smartline.png^smartline_timer.png",
+	},
+
+	drawtype = "nodebox",
+	node_box = {
+		type = "fixed",
+		fixed = {
+			{ -6/32, -6/32, 14/32,  6/32,  6/32, 16/32},
+		},
+	},
+	after_place_node = function(pos, placer)
+		local meta = minetest.get_meta(pos)
+		local events = {1,1,1,1,1,1}
+		local numbers = {"0000","","","","",""}
+		local actions = {"","","","","",""}
+		local done = {false,false,false,false,false,false}
+		local own_num = tubelib.add_node(pos, "smartline:timer")
+		meta:set_string("own_num", own_num)
+		meta:set_string("placer_name", placer:get_player_name())
+		meta:set_string("events",  minetest.serialize(events))
+		meta:set_string("numbers", minetest.serialize(numbers))
+		meta:set_string("actions", minetest.serialize(actions))
+		meta:set_string("done",  minetest.serialize(done))
+		meta:set_string("formspec", formspec(events, numbers, actions))
+		minetest.get_node_timer(pos):start(CYCLE_TIME)
+	end,
+
+	on_receive_fields = function(pos, formname, fields, player)
+		local meta = minetest.get_meta(pos)
+		if minetest.is_protected(pos, player:get_player_name()) then
+			return
+		end
+		if fields.help ~= nil then
+			meta:set_string("formspec", formspec_help())
+			return
+		end
+		local events = minetest.deserialize(meta:get_string("events"))
+		for idx, evt in ipairs({fields.e1, fields.e2, fields.e3, fields.e4, fields.e5, fields.e6}) do
+			if evt ~= nil then
+				events[idx] = tTime[evt]
+			end
+		end
+		meta:set_string("events", minetest.serialize(events))
+
+		local numbers = minetest.deserialize(meta:get_string("numbers"))
+		for idx, num in ipairs({fields.n1, fields.n2, fields.n3, fields.n4, fields.n5, fields.n6}) do
+			if num ~= nil and tubelib.check_numbers(num)then
+				numbers[idx] = num
+			end
+		end
+		meta:set_string("numbers", minetest.serialize(numbers))
+
+		local actions = minetest.deserialize(meta:get_string("actions"))
+		for idx, act in ipairs({fields.a1, fields.a2, fields.a3, fields.a4, fields.a5, fields.a6}) do
+			if act ~= nil then
+				actions[idx] = act
+			end
+		end
+		meta:set_string("actions", minetest.serialize(actions))
+	
+		meta:set_string("formspec", formspec(events, numbers, actions))
+		local done = {false,false,false,false,false,false}
+		meta:set_string("done",  minetest.serialize(done))
+	end,
+	
+	on_timer = check_rules,
+
+	after_dig_node = function(pos)
+		tubelib.remove_node(pos)
+	end,
+
+	paramtype = "light",
+	paramtype2 = "facedir",
+	sunlight_propagates = true,
+	sounds = default.node_sound_stone_defaults(),
+	groups = {choppy=2, cracky=2, crumbly=2},
+	is_ground_content = false,
+})
+
+
+minetest.register_craft({
+	output = "smartline:timer",
+	recipe = {
+		{"",         "", ""},
+		{"dye:blue", "default:copper_ingot", "tubelib:wlanchip"},
+		{"",         "default:mese_crystal", ""},
+	},
+})
+
+minetest.register_lbm({
+	label = "[Tubelib] Timer update",
+	name = "smartline:update",
+	nodenames = {"smartline:timer"},
+	run_at_every_load = false,
+	action = function(pos, node)
+		local meta = minetest.get_meta(pos)
+		local events = minetest.deserialize(meta:get_string("events"))
+		local numbers = minetest.deserialize(meta:get_string("numbers"))
+		local actions = {}
+		for _,a in ipairs(minetest.deserialize(meta:get_string("actions"))) do
+			if a == "start" then
+				actions[#actions+1] = "on"
+			elseif a == "stop" then
+				actions[#actions+1] = "off"
+			else
+				actions[#actions+1] = a
+			end
+		end
+		meta:set_string("actions", minetest.serialize(actions))
+		meta:set_string("formspec", formspec(events, numbers, actions))
+	end
+})
+
+
+

tubelib/README.md

@@ -0,0 +1,24 @@
+# Tube Library
+
+Minetest Tube Mod for item exchange via lumber tubes and wireless message communication between nodes.
+
+The focus for this Mod are:
+- minimized server load and thus minimized server lags
+- simple and intuitive usage for players
+- simple API for programmers
+
+The mod provides:
+- lumber tubes to connect 2 nodes
+- a Pusher node to pull/push items through tubes
+- a Distributor node with 4 output channels to sort incoming items
+- a Blackhole node which lets all items disappear (example/template for programmers)
+- a Button/switch node to send "switch on/off" messages
+- a Lamp node as receiving example for message communication
+- support for default node: furnace and chests
+
+Hints for Admins: ![manual.md](https://github.com/joe7575/techpack/blob/master/tubelib/manual.md)  
+Programmers Manual: ![api.md](https://github.com/joe7575/techpack/blob/master/tubelib/api.md)
+
+## Dependencies
+default  
+

tubelib/api.md

@@ -0,0 +1,288 @@
+# Tubelib Programmers Interface
+
+
+Tubelib supports:
+- StackItem exchange via tubes and
+- wireless data communication between nodes.
+
+  
+
+## 1. StackItem Exchange 
+
+Tubes represent connections between two nodes, so that it is irrelevant
+if the receiving node is nearby, or far away connected via tubes.
+The length of the tube is limited to 100 nodes.
+
+For StackItem exchange we have to distinguish the following roles:
+- client: An active node calling push/pull functions
+- server: A passive node typically with inventory, which will be called
+
+Client and server API use the following special parameters:
+
+- `side` the contact side where the items shall be pulled out or pushed in.
+  This is one of B(ack), R(ight), F(ront), L(eft), D(own), U(p) according to the
+  following diagram (view onto the placed node). It can be used to separate
+  incoming items for different inventories.
+
+```
+                        Up    Back
+                        |    /
+                        |   /
+                     +--|-----+
+                    /   o    /|
+                   +--------+ |
+          Left ----|        |o---- Right
+                   |    o   | |
+                   |   /    | +
+                   |  /     |/
+                   +-/------+
+                    /   |
+                 Front  |
+                        |
+                      Down
+```
+
+- `player_name`: Normally the name of the player, who placed the pushing node.
+  But this could also be used to identify the player interacting with the
+  pushing node.
+
+The use of both parameters on server side is not required. See chap. 4 for an example
+of an inventory node.
+
+  
+  
+## 2. Data communication
+
+For the data communication an addressing method based on node numbers is used. 
+Each registered node gets a unique node number with 4 figures (or more if needed).
+The numbers are stored in a storage list. That means, a new node, placed on 
+the same position gets the same node number as the previously placed node on that 
+position.
+
+The communication supports two services:
+- `send_message`: Send a message to one or more nodes without response
+- `send_request`: Send a messages to exactly one node and return the response
+
+It is up to the programmer, which messages shall be supported.
+But if a node can be switched on/off or started/stopped, use "on" and "off" as commands
+for both cases.
+
+  
+  
+## 3. API Functions
+
+
+### Register, Add, Remove Nodes
+
+Before a node can take part on the item exchange via tubes or data communication,
+it has to be registered once.
+
+```LUA
+    tubelib.register_node(name, add_names, node_definition)
+```
+Call this function only at load time!
+Parameters:
+- name: The node name like "tubelib:pusher"
+- add_names: A table with additional node names if needed, e.g.: "tubelib:pusher_active"
+- node_definition: A table with the server callback functions according to:
+
+```LUA
+    {
+        on_pull_item = func(pos, side, player_name),
+        -- Pull an item from the node inventory.
+        -- The function shall return an item stack with one element
+        -- like ItemStack("default:cobble") or nil.
+        -- Param side: The node contact side, where the item shall be pulled out.
+        -- Param player_name: Can be used to check access rights.
+
+        on_push_item = func(pos, side, item, player_name),
+        -- Push the given item into the node inventory.
+        -- Param side: The node contact side, where the item shall be pushed in.
+        -- Param player_name: Can be used to check access rights.
+        -- The function shall return true if successful, or false if not.
+
+        on_unpull_item = func(pos, side, item, player_name),
+        -- Undo the previous pull and place the given item back into the inventory.
+        -- Param side: The node contact side, where the item shall be unpulled.
+        -- Param player_name: Can be used to check access rights.
+        -- The function shall return true if successful, or false if not.
+
+        on_recv_message = func(pos, topic, payload),
+        -- Execute the requested message
+        -- Param topic: A topic string like "on"
+        -- Param payload: Additional data for more come complex commands, 
+        --                payload can be a number, string, or table.
+        -- The function shall return true/false for commands like on/off 
+        -- or return the requested data for commands like a "state" request.
+    }
+```
+
+**Each node has to call:**
+
+```LUA
+    tubelib.add_node(pos, name)
+```
+`add_node` shall be called when the node is placed. 
+The function is used to register the nodes position for the communication node 
+number and to update the tube surrounding.
+`pos` the node position, `name` is the node name.
+
+  
+
+```LUA
+    tubelib.remove_node(pos)
+```
+'remove_node' shall be called then the node is dig.
+The function is used to remove the node number from the internal list.
+
+  
+
+### Item Exchange via Tubes
+
+For item exchange as a pushing/pulling node the following functions exist:
+
+```LUA
+    tubelib.pull_items(pos, side, player_name)
+```
+Pull one item from the given position specified by `pos` and `side`.
+Parameters:
+- `pos` is the own node position
+- `side` is the contact side, where the item shall be pulled in 
+- `player_name` can be used to check access rights.
+- The function returns an item stack with one element like ItemStack("default:cobble") or nil.
+  
+
+```LUA
+    tubelib.push_items(pos, side, items, player_name)
+```
+Push one item to the given position specified by `pos` and `side`.
+Parameters:
+- `pos` is the own node position
+- `side` is the contact side, where the item shall be pushed out 
+- `item` is an item stack with one element like ItemStack("default:cobble")
+- `player_name` can be used to check access rights.
+The function returns true if successful, or false if not.
+
+  
+
+```LUA
+    tubelib.unpull_items(pos, side, items, player_name)`
+```
+Undo the previous pull and place the item back into the inventory.
+Parameters:
+- `pos` is the own node position
+- `side` id the node contact side, where the item shall be unpulled
+- `player_name` can be used to check access rights.
+The function returns true if successful, or false if not.
+
+  
+  
+### Wireless Data Communication
+
+For data communication the following functions exist:
+
+```LUA
+    tubelib.send_message(numbers, placer_name, clicker_name, topic, payload)
+```
+Send a message to all nodes referenced by `numbers`, a string with
+one or more destination node numbers separated by blanks. 
+The message is based on a topic string (e.g. "start") and
+a topic related payload.
+The placer and clicker names are needed to check the protection rights. 
+`placer_name` is the name of the player, who places the node.
+`clicker_name` is the name of the player, who uses the node.
+`placer_name` of sending and receiving nodes have to be the same.
+If every player should be able to send a message, use nil for `clicker_name`.
+Because several nodes could be addressed, the function don't return any response.
+
+
+```LUA
+    tubelib.send_request(number, placer_name, clicker_name, topic, payload)
+```
+In contrast to `send_message` this functions send a message to exactly one node 
+referenced by `number` and returns the node response. 
+The message is based on the topic string (e.g. "state") and
+topic related payload.
+The placer and clicker names are needed to check the protection rights. 
+`placer_name` is the name of the player, who places the node.
+`clicker_name` is the name of the player, who uses the node.
+`placer_name` of sending and receiving nodes have to be the same.
+If every player should be able to send a message, use nil for clicker_name.
+
+  
+
+## 4. Code Snippets
+
+### Register Node (from 'legacy_nodes.lua')
+
+```LUA
+    tubelib.register_node("default:chest", {"default:chest_open"}, {
+    	on_pull_item = function(pos, side, player_name)
+    		local meta = minetest.get_meta(pos)
+    		return tubelib.get_item(meta, "main")
+    	end,
+    	on_push_item = function(pos, side, item, player_name)
+    		local meta = minetest.get_meta(pos)
+    		return tubelib.put_item(meta, "main", item)
+    	end,
+    	on_unpull_item = function(pos, side, item, player_name)
+    		local meta = minetest.get_meta(pos)
+    		return tubelib.put_item(meta, "main", item)
+    	end,
+    })	
+```
+
+
+### Add/remove node (from 'lamp.lua')
+
+```LUA
+	after_place_node = function(pos, placer)
+		local number = tubelib.add_node(pos, "tubelib:lamp")
+		...
+	end,
+
+	after_dig_node = function(pos)
+		tubelib.remove_node(pos)
+	end,
+```
+
+### Item exchange via tubes (from 'pusher.lua')
+
+```LUA
+	local items = tubelib.pull_items(pos, "L", player_name)
+	if items ~= nil then
+		if tubelib.push_items(pos, "R", items, player_name) == false then
+    		tubelib.unpull_items(pos, "L", items, player_name)
+    	end
+    end
+```
+
+### Message communication (from 'button.lua')
+
+```LUA
+	local number = meta:get_string("number")
+	local placer_name = meta:get_string("placer_name")
+	tubelib.send_message(number, placer_name, nil, "stop", nil)
+```
+
+### 5. Example Code
+
+Tubelib includes the following example nodes which can be used for study
+and as templates for own projects:
+
+- pusher.lua:    a simple client pushing/pulling items
+- blackhole.lua: a simple server client, makes all items disappear
+- button.lua:    a simple communication node, only sending messages
+- lamp.lua:      a simple communication node, only receiving messages
+
+
+## 6. Further information
+
+The complete functionality is implemented in the file 
+![command.lua](https://github.com/joe7575/Minetest-Tubelib/blob/master/command.lua). 
+This file has further helper functions and is recommended for deeper study.
+
+## 7. History
+
+2017-10-02  First draft  
+2017-10-29  Commands start/stop replaced by on/off

tubelib/blackhole.lua

@@ -0,0 +1,96 @@
+--[[
+
+	Tube Library
+	============
+
+	Copyright (C) 2017 Joachim Stolberg
+
+	LGPLv2.1+
+	See LICENSE.txt for more information
+
+	blackhole.lua:
+	
+	Simple node which lets all items disappear.
+	The blackhole supports the following message:
+	- topic = "status", payload  = nil, 
+	  response is the number of disappeared items (0..n)
+]]--
+
+--                 +--------+
+--                /        /|
+--               +--------+ |
+--     IN (L) -->|  BLACK | |          
+--               |  HOLE  | +
+--               |        |/
+--               +--------+
+
+
+minetest.register_node("tubelib:blackhole", {
+	description = "Tubelib Black Hole",
+	tiles = {
+		-- up, down, right, left, back, front
+		'tubelib_front.png',
+		'tubelib_front.png',
+		'tubelib_black_hole.png',
+		'tubelib_black_hole_inp.png',
+		"tubelib_black_hole.png",
+		"tubelib_black_hole.png",
+	},
+
+	after_place_node = function(pos, placer)
+		local meta = minetest.get_meta(pos)
+		local number = tubelib.add_node(pos, "tubelib:blackhole") -- <<=== tubelib
+		meta:set_string("number", number)
+		meta:set_int("disappeared", 0)
+		meta:set_string("infotext","0 items disappeared")
+	end,
+
+	after_dig_node = function(pos)
+		tubelib.remove_node(pos) -- <<=== tubelib
+	end,
+
+	paramtype = "light",
+	sunlight_propagates = true,
+	paramtype2 = "facedir",
+	groups = {choppy=2, cracky=2, crumbly=2},
+	is_ground_content = false,
+	sounds = default.node_sound_wood_defaults(),
+})
+
+
+
+minetest.register_craft({
+	output = "tubelib:blackhole 2",
+	recipe = {
+		{"group:wood",    "",                   "group:wood"},
+		{"tubelib:tube1", "default:coal_lump",  "default:coal_lump"},
+		{"group:wood",    "",                   "group:wood"},
+	},
+})
+
+--------------------------------------------------------------- tubelib
+tubelib.register_node("tubelib:blackhole", {}, {
+	on_pull_item = nil,  		-- not needed
+	on_unpull_item = nil,		-- not needed
+	
+	on_push_item = function(pos, side, item)
+		if side == "L" then
+			local meta = minetest.get_meta(pos)
+			local disappeared = meta:get_int("disappeared") + 1
+			meta:set_int("disappeared", disappeared)
+			meta:set_string("infotext", disappeared.." items disappeared")
+			return true		
+		end
+		return false
+	end,
+	
+	on_recv_message = function(pos, topic, payload)
+		local node = minetest.get_node(pos)
+		if topic == "state" then
+			return meta:get_int("disappeared")
+		else
+			return "not supported"
+		end
+	end,
+})	
+--------------------------------------------------------------- tubelib

tubelib/button.lua

@@ -0,0 +1,173 @@
+--[[
+
+	Tube Library
+	============
+
+	Copyright (C) 2017 Joachim Stolberg
+
+	LGPLv2.1+
+	See LICENSE.txt for more information
+
+	button.lua:
+	
+	Example of a simple communication node, only sending messages to other nodes.
+
+]]--
+
+
+local function switch_on(pos, node)
+	node.name = "tubelib:button_active"
+	minetest.swap_node(pos, node)
+	minetest.sound_play("button", {
+			pos = pos,
+			gain = 0.5,
+			max_hear_distance = 5,
+		})
+	local meta = minetest.get_meta(pos)
+	local own_num = meta:get_string("own_num")
+	local numbers = meta:get_string("numbers")
+	local cycle_time = meta:get_int("cycle_time")
+	if cycle_time > 0 then 	-- button mode?
+		minetest.get_node_timer(pos):start(cycle_time)
+	end
+	local placer_name = meta:get_string("placer_name")
+	local clicker_name = nil
+	if meta:get_string("public") == "false" then
+		clicker_name = meta:get_string("clicker_name")
+	end
+	tubelib.send_message(numbers, placer_name, clicker_name, "on", own_num)  -- <<=== tubelib
+end
+
+local function switch_off(pos)
+	local node = minetest.get_node(pos)
+	node.name = "tubelib:button"
+	minetest.swap_node(pos, node)
+	minetest.get_node_timer(pos):stop()
+	minetest.sound_play("button", {
+			pos = pos,
+			gain = 0.5,
+			max_hear_distance = 5,
+		})
+	local meta = minetest.get_meta(pos)
+	local own_num = meta:get_string("own_num")
+	local numbers = meta:get_string("numbers")
+	local placer_name = meta:get_string("placer_name")
+	tubelib.send_message(numbers, placer_name, nil, "off", own_num)  -- <<=== tubelib
+end
+
+
+minetest.register_node("tubelib:button", {
+	description = "Tubelib Button/Switch",
+	tiles = {
+		-- up, down, right, left, back, front
+		'tubelib_front.png',
+		'tubelib_button.png',
+		'tubelib_button.png',
+		'tubelib_button.png',
+		'tubelib_button.png',
+		"tubelib_button_off.png",
+	},
+
+	after_place_node = function(pos, placer)
+		local meta = minetest.get_meta(pos)
+		local own_num = tubelib.add_node(pos, "tubelib:button")
+		meta:set_string("own_num", own_num)
+		meta:set_string("formspec", "size[5,6]"..
+		"dropdown[0.2,0;3;type;switch,button 2s,button 4s,button 8s,button 16s;1]".. 
+		"field[0.5,2;3,1;numbers;Insert destination block number(s);]" ..
+		"checkbox[1,3;public;public;false]"..
+		"button_exit[1,4;2,1;exit;Save]")
+		meta:set_string("placer_name", placer:get_player_name())
+		meta:set_string("public", "false")
+		meta:set_int("cycle_time", 0)
+		meta:set_string("infotext", "Tubelib Button "..own_num)
+	end,
+
+	on_receive_fields = function(pos, formname, fields, player)
+		local meta = minetest.get_meta(pos)
+		if tubelib.check_numbers(fields.numbers) then  -- <<=== tubelib
+			meta:set_string("numbers", fields.numbers)
+			local own_num = meta:get_string("own_num")
+			meta:set_string("infotext", "Tubelib Button "..own_num..", connected with block "..fields.numbers)
+		else
+			return
+		end
+		if fields.public then
+			meta:set_string("public", fields.public)
+		end
+		local cycle_time = nil
+		if fields.type == "switch" then
+			cycle_time = 0
+		elseif fields.type == "button 2s" then
+			cycle_time = 2
+		elseif fields.type == "button 4s" then
+			cycle_time = 4
+		elseif fields.type == "button 8s" then
+			cycle_time = 8
+		elseif fields.type == "button 16s" then
+			cycle_time = 16
+		end
+		if cycle_time ~= nil then
+			meta:set_int("cycle_time", cycle_time)
+		end
+		if fields.exit then
+			meta:set_string("formspec", nil)
+		end
+	end,
+	
+	on_rightclick = function(pos, node, clicker)
+		local meta = minetest.get_meta(pos)
+		if meta:get_string("numbers") then
+			meta:set_string("clicker_name", clicker:get_player_name())
+			switch_on(pos, node)
+		end
+	end,
+
+	paramtype = "light",
+	sunlight_propagates = true,
+	paramtype2 = "facedir",
+	groups = {choppy=2, cracky=2, crumbly=2},
+	is_ground_content = false,
+	sounds = default.node_sound_wood_defaults(),
+})
+
+
+minetest.register_node("tubelib:button_active", {
+	description = "Tubelib Button/Switch",
+	tiles = {
+		-- up, down, right, left, back, front
+		'tubelib_front.png',
+		'tubelib_button.png',
+		'tubelib_button.png',
+		'tubelib_button.png',
+		'tubelib_button.png',
+		"tubelib_button_on.png",
+	},
+
+	on_rightclick = function(pos, node, clicker)
+		local meta = minetest.get_meta(pos)
+		meta:set_string("clicker_name", clicker:get_player_name())
+		if meta:get_int("cycle_time") == nil or meta:get_int("cycle_time") == 0 then
+			switch_off(pos, node)
+		end
+	end,
+
+	on_timer = switch_off,
+
+	paramtype = "light",
+	sunlight_propagates = true,
+	paramtype2 = "facedir",
+	groups = {crumbly=0, not_in_creative_inventory=1},
+	is_ground_content = false,
+	sounds = default.node_sound_wood_defaults(),
+})
+
+minetest.register_craft({
+	output = "tubelib:button",
+	recipe = {
+		{"",              "group:wood",  	    ""},
+		{"default:glass", "tubelib:wlanchip",	""},
+		{"",              "group:wood",  	    ""},
+	},
+})
+

tubelib/command.lua

@@ -0,0 +1,423 @@
+--[[
+
+	Tube Library
+	============
+
+	Copyright (C) 2017 Joachim Stolberg
+
+	LGPLv2.1+
+	See LICENSE.txt for more information
+
+	command.lua:
+
+  See [api.md] for the interface documentation
+
+]]--
+
+-------------------------------------------------------------------
+-- Data base storage
+-------------------------------------------------------------------
+local storage = minetest.get_mod_storage()
+local NextNumber = minetest.deserialize(storage:get_string("NextNumber")) or 1
+local Version = minetest.deserialize(storage:get_string("Version")) or 1
+local Number2Pos = minetest.deserialize(storage:get_string("Number2Pos")) or {}
+
+local function update_mod_storage()
+	storage:set_string("NextNumber", minetest.serialize(NextNumber))
+	storage:set_string("Version", minetest.serialize(Version))
+	storage:set_string("Number2Pos", minetest.serialize(Number2Pos))
+	storage:set_string("Key2Number", nil) -- not used any more 
+	-- store data each hour
+	minetest.after(60*60, update_mod_storage)
+	print("[Tubelib] Data stored")
+end
+
+minetest.register_on_shutdown(function()
+	update_mod_storage()
+end)
+
+-- store data after one hour
+minetest.after(60*60, update_mod_storage)
+
+-- Key2Number will be generated at runtine
+local Key2Number = {} 
+
+local Name2Name = {}		-- translation table
+
+-------------------------------------------------------------------
+-- Local helper functions
+-------------------------------------------------------------------
+
+-- Localize functions to avoid table lookups (better performance).
+local string_find = string.find
+local string_split = string.split
+local tubelib_NodeDef = tubelib.NodeDef
+local get_neighbor_pos = tubelib.get_neighbor_pos
+local read_node_with_vm = tubelib.read_node_with_vm
+
+-- Translate from facedir to contact side of the other node
+-- (left for one is right for the other node)
+local FacedirToSide = {[0] = "F", "L", "B", "R", "U", "D"}
+
+-- Generate a key string based on the given pos table,
+-- Used internaly as table key,
+local function get_key_str(pos)
+	pos = minetest.pos_to_string(pos)
+	return string.sub(pos, 2, -2)
+end
+
+-- Determine position related node number for addressing purposes
+local function get_number(pos)
+	local key = get_key_str(pos)
+	if not Key2Number[key] then
+		Key2Number[key] = NextNumber
+		NextNumber = NextNumber + 1
+	end
+	return string.format("%.04u", Key2Number[key])
+end
+
+-- Determine the contact side of the node at the given pos
+-- param facedir: facedir to the node
+local function get_node_side(npos, facedir)	
+	local node = minetest.get_node_or_nil(npos) or read_node_with_vm(npos)
+	if facedir < 4 then
+		facedir = (facedir - node.param2 + 4) % 4
+	end
+	return FacedirToSide[facedir], node
+end
+
+local function generate_Key2Number()
+	local key
+	for num,item in pairs(Number2Pos) do
+		key = get_key_str(item.pos)
+		Key2Number[key] = num
+	end
+end
+
+-------------------------------------------------------------------
+-- API helper functions
+-------------------------------------------------------------------
+	
+-- Check the given list of numbers.
+-- Returns true if number(s) is/are valid and point to real nodes.
+function tubelib.check_numbers(numbers)
+	if numbers then
+		for _,num in ipairs(string_split(numbers, " ")) do
+			if Number2Pos[num] == nil then
+				return false
+			end
+		end
+		return true
+	end
+	return false
+end	
+
+-- Function returns { pos, name } for the node on the given position number.
+function tubelib.get_node_info(dest_num)
+	if Number2Pos[dest_num] then
+		return Number2Pos[dest_num]
+	end
+	return nil
+end	
+
+-- Function returns the node number from the given position or
+-- nil, if no node number for this position is assigned.
+function tubelib.get_node_number(pos)
+	local key = get_key_str(pos)
+	local num = Key2Number[key]
+	if num then
+		num = string.format("%.04u", num)
+		if Number2Pos[num] and Number2Pos[num].name then
+			return num
+		end
+	end
+	return nil
+end	
+
+-- Store any node number related, additional data
+-- param number: node number, returned by tubelib.add_node
+-- param name: name of the data (string)
+-- param data: any data (number, string, table)
+function tubelib.set_data(number, name, data)
+	if Number2Pos[number] and type(name) == "string" then
+		Number2Pos[number]["u_"..name] = data
+	end
+end
+
+-- Read node number related data
+-- param number: node number, returned by tubelib.add_node
+-- param name: name of the data (string)
+function tubelib.get_data(number, name)
+	if Number2Pos[number] and type(name) == "string" then
+		return Number2Pos[number]["u_"..name]
+	end
+	return nil
+end
+
+-------------------------------------------------------------------
+-- Node construction/destruction functions
+-------------------------------------------------------------------
+	
+-- Add node to the tubelib lists and update the tube surrounding.
+-- Function determines and returns the node position number,
+-- needed for message communication.
+function tubelib.add_node(pos, name)
+	-- store position 
+	local number = get_number(pos)
+	Number2Pos[number] = {
+		pos = pos, 
+		name = name,
+	}
+	-- update surrounding tubes
+	tubelib.update_tubes(pos)
+	return number
+end
+
+-- Function removes the node from the tubelib lists.
+function tubelib.remove_node(pos)
+	local number = get_number(pos)
+	if Number2Pos[number] then
+		Number2Pos[number] = {
+			pos = pos, 
+			name = nil,
+			time = minetest.get_day_count() -- used for aging
+		}
+	end
+end
+
+
+-------------------------------------------------------------------
+-- Node register function
+-------------------------------------------------------------------
+
+-- Register node for tubelib communication
+-- Call this function only at load time!
+-- Param name: The node name like "tubelib:pusher"
+-- Param add_names: Alternativ node names if needded, e.g.: "tubelib:pusher_active"
+-- Param node_definition: A table according to:
+--    {
+--        on_pull_item = func(pos, side, player_name),
+--        on_push_item = func(pos, side, item, player_name),
+--        on_unpull_item = func(pos, side, item, player_name),
+--        on_recv_message = func(pos, topic, payload),
+--    }
+function tubelib.register_node(name, add_names, node_definition)
+	tubelib_NodeDef[name] = node_definition
+	-- store facedir table for all known node names
+	tubelib.knownNodes[name] = true
+	Name2Name[name] = name
+	for _,n in ipairs(add_names) do
+		tubelib.knownNodes[n] = true
+		Name2Name[n] = name
+	end
+end
+
+-------------------------------------------------------------------
+-- Send message functions
+-------------------------------------------------------------------
+
+function tubelib.send_message(numbers, placer_name, clicker_name, topic, payload)
+	for _,num in ipairs(string_split(numbers, " ")) do
+		if Number2Pos[num] and Number2Pos[num].name then
+			local data = Number2Pos[num]
+			if placer_name and not minetest.is_protected(data.pos, placer_name) then
+				if clicker_name == nil or not minetest.is_protected(data.pos, clicker_name) then
+					if data and data.name then
+						if tubelib_NodeDef[data.name] and tubelib_NodeDef[data.name].on_recv_message then
+							tubelib_NodeDef[data.name].on_recv_message(data.pos, topic, payload)
+						end
+					end
+				end
+			end
+		end
+	end
+end		
+
+function tubelib.send_request(number, topic, payload)
+	if Number2Pos[number] and Number2Pos[number].name then
+		local data = Number2Pos[number]
+		if data and data.name then
+			if tubelib_NodeDef[data.name] and tubelib_NodeDef[data.name].on_recv_message then
+				return tubelib_NodeDef[data.name].on_recv_message(data.pos, topic, payload)
+			end
+		end
+	end
+	return false
+end		
+
+-------------------------------------------------------------------
+-- Client side Push/Pull item functions
+-------------------------------------------------------------------
+
+function tubelib.pull_items(pos, side, player_name)
+	local npos, facedir = get_neighbor_pos(pos, side)
+	local nside, node = get_node_side(npos, facedir)
+	local name = Name2Name[node.name]
+	if tubelib_NodeDef[name] and tubelib_NodeDef[name].on_pull_item then
+		return tubelib_NodeDef[name].on_pull_item(npos, nside, player_name)
+	end
+	return nil
+end
+
+function tubelib.push_items(pos, side, items, player_name)
+	local npos, facedir = get_neighbor_pos(pos, side)
+	local nside, node = get_node_side(npos, facedir)
+	local name = Name2Name[node.name]
+	if tubelib_NodeDef[name] and tubelib_NodeDef[name].on_push_item then
+		return tubelib_NodeDef[name].on_push_item(npos, nside, items, player_name)	
+	elseif node.name == "air" then
+		minetest.add_item(npos, items)
+		return true 
+	end
+	return false
+end
+
+function tubelib.unpull_items(pos, side, items, player_name)
+	local npos, facedir = get_neighbor_pos(pos, side)
+	local nside, node = get_node_side(npos, facedir)
+	local name = Name2Name[node.name]
+	if tubelib_NodeDef[name] and tubelib_NodeDef[name].on_unpull_item then
+		return tubelib_NodeDef[name].on_unpull_item(npos, nside, items, player_name)
+	end
+	return false
+end
+	
+
+-------------------------------------------------------------------
+-- Server side helper functions
+-------------------------------------------------------------------
+
+-- Get one item from the given ItemList. The position within the list
+-- is incremented each time so that different item stacks will be considered.
+-- Returns nil if ItemList is empty.
+function tubelib.get_item(meta, listname)
+	if meta == nil or meta.get_inventory == nil then return nil end
+	local inv = meta:get_inventory()
+	if inv:is_empty(listname) then
+		return nil
+	end
+	local size = inv:get_size(listname)
+	local startpos = meta:get_int("tubelib_startpos") or 0
+	for idx = startpos, startpos+size do
+		idx = (idx % size) + 1
+		local items = inv:get_stack(listname, idx)
+		if items:get_count() > 0 then
+			local taken = items:take_item(1)
+			inv:set_stack(listname, idx, items)
+			meta:set_int("tubelib_startpos", idx)
+			return taken
+		end
+	end
+	meta:set_int("tubelib_startpos", 0)
+	return nil
+end
+
+-- Get one item from the given ItemList, specified by stack number (1..n).
+-- Returns nil if ItemList is empty.
+function tubelib.get_this_item(meta, listname, number)
+	if meta == nil or meta.get_inventory == nil then return nil end
+	local inv = meta:get_inventory()
+	if inv:is_empty(listname) then
+		return nil
+	end
+	
+	local items = inv:get_stack(listname, number)
+	if items:get_count() > 0 then
+		local taken = items:take_item(1)
+		inv:set_stack(listname, number, items)
+		return taken
+	end
+	return nil
+end
+
+
+-- Put the given item into the given ItemList.
+-- Function returns false if ItemList is full.
+function tubelib.put_item(meta, listname, item)
+	if meta == nil or meta.get_inventory == nil then return false end
+	local inv = meta:get_inventory()
+	if inv:room_for_item(listname, item) then
+		inv:add_item(listname, item)
+		return true
+	end
+	return false
+end
+
+-- Take the number of items from the given ItemList.
+-- Returns nil if the requested number is not available.
+function tubelib.get_num_items(meta, listname, num)
+	if meta == nil or meta.get_inventory == nil then return nil end
+	local inv = meta:get_inventory()
+	if inv:is_empty(listname) then
+		return nil
+	end
+	local size = inv:get_size(listname)
+	for idx = 1, size do
+		local items = inv:get_stack(listname, idx)
+		if items:get_count() >= num then
+			local taken = items:take_item(num)
+			inv:set_stack(listname, idx, items)
+			return taken
+		end
+	end
+	return nil
+end
+
+-- Return "full", "loaded", or "empty" depending
+-- on the number of fuel stack items.
+-- Function only works on fuel inventories with one stacks/99 items
+function tubelib.fuelstate(meta, listname, item)
+	if meta == nil or meta.get_inventory == nil then return nil end
+	local inv = meta:get_inventory()
+	if inv:is_empty(listname) then
+		return "empty"
+	end
+	local list = inv:get_list(listname)
+	if #list == 1 and list[1]:get_count() == 99 then
+		return "full"
+	else
+		return "loaded"
+	end
+end
+	
+
+
+-------------------------------------------------------------------------------
+-- Data Maintenance
+-------------------------------------------------------------------------------
+local function data_maintenance()
+	print("[Tubelib] Data maintenance started")
+	if Version == 1 then
+		-- Add day_count for aging of unused positions
+		for num,item in pairs(Number2Pos) do
+			if Number2Pos[num].name == nil then
+				Number2Pos[num].time = minetest.get_day_count()
+			end
+		end
+		Version = 2
+	else
+		-- Remove old unused positions
+		local Tbl = table.copy(Number2Pos)
+		Number2Pos = {}
+		local day_cnt = minetest.get_day_count()
+		for num,item in pairs(Tbl) do
+			if item.name then
+				Number2Pos[num] = item
+			-- data not older than 5 real days
+			elseif item.time and (item.time + 360) > day_cnt then
+				Number2Pos[num] = item
+			else
+				print("Position deleted", num)
+			end
+		end
+	end
+	print("[Tubelib] Data maintenance finished")
+end	
+	
+generate_Key2Number()
+
+-- maintain data after one minute
+-- (minetest.get_day_count() will not be valid at start time)
+minetest.after(60, data_maintenance)
+
+

tubelib/depends.txt

@@ -0,0 +1 @@
+default

tubelib/description.txt

@@ -0,0 +1,2 @@
+Tubes Mod with message communication interface as basis for further technique Mods.
+

tubelib/distributor.lua

@@ -0,0 +1,449 @@
+--[[
+
+	Tube Library
+	============
+
+	Copyright (C) 2017 Joachim Stolberg
+
+	LGPLv2.1+
+	See LICENSE.txt for more information
+
+	distributor.lua:
+	
+	A more complex node acting as server and client.
+	This node claims a position number and registers its message and items interface.
+	The Distributor supports the following messages:
+	 - topic = "on", payload  = nil
+	 - topic = "off" , payload  = nil
+	 - topic = "state", payload  = nil, 
+	   response is "running", "stopped", "standby", or "not supported"
+]]--
+
+local NUM_FILTER_ELEM = 6
+local NUM_FILTER_SLOTS = 4
+local TICKS_TO_SLEEP = 5
+local CYCLE_TIME = 2
+local STOP_STATE = 0
+local STANDBY_STATE = -1
+local FAULT_STATE = -2
+
+-- Return a key/value table with all items and the corresponding stack numbers
+local function invlist_content_as_kvlist(list)
+	local res = {}
+	for idx,items in ipairs(list) do
+		local name = items:get_name()
+		if name ~= "" then
+			res[name] = idx
+		end
+	end
+	return res
+end
+
+-- Return the total number of list entries
+local function invlist_num_entries(list)
+	local res = 0
+	for _,items in ipairs(list) do
+		local name = items:get_name()
+		if name ~= "" then
+			res = res + items:get_count()
+		end
+	end
+	return res
+end
+
+-- Return a flat table with all items
+local function invlist_entries_as_list(list)
+	local res = {}
+	for _,items in ipairs(list) do
+		local name = items:get_name()
+		local count = items:get_count()
+		if name ~= "" then
+			for i = 1,count do
+				res[#res+1] = name
+			end
+		end
+	end
+	return res
+end
+
+
+local function AddToTbl(kvTbl, new_items)
+	for _, l in ipairs(new_items) do 
+		kvTbl[l] = true 
+	end
+	return kvTbl
+end
+
+
+local function distributor_formspec(state, filter)
+	return "size[10,8.5]"..
+	default.gui_bg..
+	default.gui_bg_img..
+	default.gui_slots..
+	"list[context;src;0,0;2,4;]"..
+	"image[2,1.5;1,1;tubelib_gui_arrow.png]"..
+	"image_button[2,3;1,1;".. tubelib.state_button(state) ..";button;]"..
+	"checkbox[3,0;filter1;On;"..dump(filter[1]).."]"..
+	"checkbox[3,1;filter2;On;"..dump(filter[2]).."]"..
+	"checkbox[3,2;filter3;On;"..dump(filter[3]).."]"..
+	"checkbox[3,3;filter4;On;"..dump(filter[4]).."]"..
+	"image[3.6,0;0.3,1;tubelib_red.png]"..
+	"image[3.6,1;0.3,1;tubelib_green.png]"..
+	"image[3.6,2;0.3,1;tubelib_blue.png]"..
+	"image[3.6,3;0.3,1;tubelib_yellow.png]"..
+	"list[context;red;4,0;6,1;]"..
+	"list[context;green;4,1;6,1;]"..
+	"list[context;blue;4,2;6,1;]"..
+	"list[context;yellow;4,3;6,1;]"..
+	"list[current_player;main;1,4.5;8,4;]"..
+	"listring[context;src]"..
+	"listring[current_player;main]"
+end
+
+local function allow_metadata_inventory_put(pos, listname, index, stack, player)
+	local meta = minetest.get_meta(pos)
+	local inv = meta:get_inventory()
+	local list = inv:get_list(listname)
+	
+	if minetest.is_protected(pos, player:get_player_name()) then
+		return 0
+	end
+	if listname == "src" then
+		return stack:get_count()
+	elseif invlist_num_entries(list) < NUM_FILTER_ELEM then
+		return 1
+	end
+	return 0
+end
+
+local function allow_metadata_inventory_take(pos, listname, index, stack, player)
+	if minetest.is_protected(pos, player:get_player_name()) then
+		return 0
+	end
+	return stack:get_count()
+end
+
+local function allow_metadata_inventory_move(pos, from_list, from_index, to_list, to_index, count, player)
+	local meta = minetest.get_meta(pos)
+	local inv = meta:get_inventory()
+	local stack = inv:get_stack(from_list, from_index)
+	return allow_metadata_inventory_put(pos, to_list, to_index, stack, player)
+end
+
+local SlotColors = {"red", "green", "blue", "yellow"}
+local Num2Ascii = {"B", "L", "F", "R"} -- color to side translation
+local FilterCache = {} -- local cache for filter settings
+
+local function filter_settings(pos)
+	local hash = minetest.hash_node_position(pos)
+	local meta = minetest.get_meta(pos)
+	local inv = meta:get_inventory()
+	local filter = minetest.deserialize(meta:get_string("filter")) or {false,false,false,false}
+	local kvFilterItemNames = {} -- {<item:name> = true,...}
+	local kvSide2ItemNames = {} -- {"F" = {<item:name>,...},...}
+	
+	-- collect all filter settings
+	for idx,slot in ipairs(SlotColors) do
+		local side = Num2Ascii[idx]
+		if filter[idx] == true then
+			local list = inv:get_list(slot)
+			local filter = invlist_entries_as_list(list)
+			AddToTbl(kvFilterItemNames, filter)
+			kvSide2ItemNames[side] = filter
+		end
+	end
+	
+	FilterCache[hash] = {
+		kvFilterItemNames = kvFilterItemNames, 
+		kvSide2ItemNames = kvSide2ItemNames
+	}
+end
+
+local function start_the_machine(pos)
+	local node = minetest.get_node(pos)
+	local meta = minetest.get_meta(pos)
+	local number = meta:get_string("number")
+	meta:set_int("running", TICKS_TO_SLEEP)
+	node.name = "tubelib:distributor_active"
+	minetest.swap_node(pos, node)
+	meta:set_string("infotext", "Tubelib Distributor "..number..": running")
+	local filter = minetest.deserialize(meta:get_string("filter"))
+	meta:set_string("formspec", distributor_formspec(tubelib.RUNNING, filter))
+	minetest.get_node_timer(pos):start(CYCLE_TIME)
+	return false
+end
+
+local function stop_the_machine(pos)
+	local node = minetest.get_node(pos)
+	local meta = minetest.get_meta(pos)
+	local number = meta:get_string("number")
+	meta:set_int("running", STOP_STATE)
+	node.name = "tubelib:distributor"
+	minetest.swap_node(pos, node)
+	meta:set_string("infotext", "Tubelib Distributor "..number..": stopped")
+	local filter = minetest.deserialize(meta:get_string("filter"))
+	meta:set_string("formspec", distributor_formspec(tubelib.STOPPED, filter))
+	minetest.get_node_timer(pos):stop()
+	return false
+end
+
+local function goto_sleep(pos)
+	local node = minetest.get_node(pos)
+	local meta = minetest.get_meta(pos)
+	local number = meta:get_string("number")
+	meta:set_int("running", STANDBY_STATE)
+	node.name = "tubelib:distributor"
+	minetest.swap_node(pos, node)
+	meta:set_string("infotext", "Tubelib Distributor "..number..": standby")
+	local filter = minetest.deserialize(meta:get_string("filter"))
+	meta:set_string("formspec", distributor_formspec(tubelib.STANDBY, filter))
+	minetest.get_node_timer(pos):start(CYCLE_TIME * TICKS_TO_SLEEP)
+	return false
+end	
+
+-- move items to the output slots
+local function keep_running(pos, elapsed)
+	local meta = minetest.get_meta(pos)
+	local running = meta:get_int("running") - 1
+	local player_name = meta:get_string("player_name")
+	--print("running", running)
+	local slot_idx = meta:get_int("slot_idx") or 1
+	meta:set_int("slot_idx", (slot_idx + 1) % NUM_FILTER_SLOTS)
+	local side = Num2Ascii[slot_idx+1]
+	local listname = SlotColors[slot_idx+1]
+	local inv = meta:get_inventory()
+	local list = inv:get_list("src")
+	local kvSrc = invlist_content_as_kvlist(list)
+	
+	-- calculate the filter settings only once
+	local hash = minetest.hash_node_position(pos)
+	if FilterCache[hash] == nil then
+		filter_settings(pos)
+	end
+	
+	-- read data from Cache 
+	-- all filter items as key/value  {<item:name> = true,...}
+	local kvFilterItemNames = FilterCache[hash].kvFilterItemNames
+	-- filter items of one slot as list  {<item:name>,...}
+	local names = FilterCache[hash].kvSide2ItemNames[side]
+	
+	if names == nil then
+		-- this slot is empty
+		return true
+	end
+	
+	local busy = false
+	-- move items from configured filters to the output
+	if next(names) then
+		for _,name in ipairs(names) do
+			if kvSrc[name] then
+				local item = tubelib.get_this_item(meta, "src", kvSrc[name]) -- <<=== tubelib
+				if item then
+					if not tubelib.push_items(pos, side, item, player_name) then -- <<=== tubelib
+						tubelib.put_item(meta, "src", item)
+					else
+						busy = true
+					end
+				end
+			end
+		end
+	end
+	
+	-- move additional items from unconfigured filters to the output
+	if next(names) == nil then
+		for name,_ in pairs(kvSrc) do
+			if kvFilterItemNames[name] == nil then  -- not in the filter so far?
+				local item = tubelib.get_this_item(meta, "src", kvSrc[name]) -- <<=== tubelib
+				if item then
+					if not tubelib.push_items(pos, side, item, player_name) then -- <<=== tubelib
+						tubelib.put_item(meta, "src", item)
+					else
+						busy = true
+					end
+				end
+			end
+		end
+	end
+	
+	if busy == true then 
+		if running <= 0 then
+			return start_the_machine(pos)
+		else
+			running = TICKS_TO_SLEEP
+		end
+	else
+		if running <= 0 then
+			return goto_sleep(pos)
+		end
+	end
+	
+	meta:set_int("running", running)
+	return true
+end
+
+local function on_receive_fields(pos, formname, fields, player)
+	if minetest.is_protected(pos, player:get_player_name()) then
+		return
+	end
+	local meta = minetest.get_meta(pos)
+	local running = meta:get_int("running")
+	local filter = minetest.deserialize(meta:get_string("filter"))
+	if fields.filter1 ~= nil then
+		filter[1] = fields.filter1 == "true"
+	elseif fields.filter2 ~= nil then
+		filter[2] = fields.filter2 == "true"
+	elseif fields.filter3 ~= nil then
+		filter[3] = fields.filter3 == "true"
+	elseif fields.filter4 ~= nil then
+		filter[4] = fields.filter4 == "true"
+	end
+	meta:set_string("filter", minetest.serialize(filter))
+	
+	filter_settings(pos)
+	
+	if fields.button ~= nil then
+		if running > STOP_STATE or running == FAULT_STATE then
+			stop_the_machine(pos)
+		else
+			start_the_machine(pos)
+		end
+	else
+		meta:set_string("formspec", distributor_formspec(tubelib.state(running), filter))
+	end
+end
+
+minetest.register_node("tubelib:distributor", {
+	description = "Tubelib Distributor",
+	tiles = {
+		-- up, down, right, left, back, front
+		'tubelib_distributor.png',
+		'tubelib_distributor.png',
+		'tubelib_distributor_yellow.png',
+		'tubelib_distributor_green.png',
+		"tubelib_distributor_red.png",
+		"tubelib_distributor_blue.png",
+	},
+
+	after_place_node = function(pos, placer)
+		local number = tubelib.add_node(pos, "tubelib:distributor") -- <<=== tubelib
+		local meta = minetest.get_meta(pos)
+		meta:set_string("player_name", placer:get_player_name())
+
+		local filter = {false,false,false,false}
+		meta:set_string("formspec", distributor_formspec(tubelib.STOPPED, filter))
+		meta:set_string("filter", minetest.serialize(filter))
+		meta:set_string("number", number)
+		meta:set_string("infotext", "Tubelib Distributor "..number..": stopped")
+		local inv = meta:get_inventory()
+		inv:set_size('src', 8)
+		inv:set_size('yellow', 6)
+		inv:set_size('green', 6)
+		inv:set_size('red', 6)
+		inv:set_size('blue', 6)
+	end,
+
+	on_receive_fields = on_receive_fields,
+
+	on_dig = function(pos, node, puncher, pointed_thing)
+		if minetest.is_protected(pos, puncher:get_player_name()) then
+			return
+		end
+		local meta = minetest.get_meta(pos)
+		local inv = meta:get_inventory()
+		if inv:is_empty("src") then
+			minetest.node_dig(pos, node, puncher, pointed_thing)
+			tubelib.remove_node(pos) -- <<=== tubelib
+		end
+	end,
+
+	allow_metadata_inventory_put = allow_metadata_inventory_put,
+	allow_metadata_inventory_take = allow_metadata_inventory_take,
+	allow_metadata_inventory_move = allow_metadata_inventory_move,
+
+	on_timer = keep_running,
+	
+	paramtype = "light",
+	sunlight_propagates = true,
+	paramtype2 = "facedir",
+	groups = {choppy=2, cracky=2, crumbly=2},
+	is_ground_content = false,
+	sounds = default.node_sound_wood_defaults(),
+})
+
+
+minetest.register_node("tubelib:distributor_active", {
+	description = "Tubelib Distributor",
+	tiles = {
+		-- up, down, right, left, back, front
+		{
+			image = "tubelib_distributor_active.png",
+			backface_culling = false,
+			animation = {
+				type = "vertical_frames",
+				aspect_w = 32,
+				aspect_h = 32,
+				length = 2.0,
+			},
+		},
+		'tubelib_distributor.png',
+		'tubelib_distributor_yellow.png',
+		'tubelib_distributor_green.png',
+		"tubelib_distributor_red.png",
+		"tubelib_distributor_blue.png",
+	},
+
+	on_receive_fields = on_receive_fields,
+	
+	allow_metadata_inventory_put = allow_metadata_inventory_put,
+	allow_metadata_inventory_take = allow_metadata_inventory_take,
+	allow_metadata_inventory_move = allow_metadata_inventory_move,
+
+	on_timer = keep_running,
+
+	paramtype = "light",
+	sunlight_propagates = true,
+	paramtype2 = "facedir",
+	groups = {crumbly=0, not_in_creative_inventory=1},
+	is_ground_content = false,
+	sounds = default.node_sound_wood_defaults(),
+})
+
+minetest.register_craft({
+	output = "tubelib:distributor 2",
+	recipe = {
+		{"group:wood", 		"default:steel_ingot",  "group:wood"},
+		{"tubelib:tube1", 	"default:mese_crystal",	"tubelib:tube1"},
+		{"group:wood", 		"default:steel_ingot",  "group:wood"},
+	},
+})
+
+
+--------------------------------------------------------------- tubelib
+tubelib.register_node("tubelib:distributor", {"tubelib:distributor_active"}, {
+	on_pull_item = function(pos, side)
+		local meta = minetest.get_meta(pos)
+		return tubelib.get_item(meta, "src")
+	end,
+	on_push_item = function(pos, side, item)
+		local meta = minetest.get_meta(pos)
+		return tubelib.put_item(meta, "src", item)
+	end,
+	on_unpull_item = function(pos, side, item)
+		local meta = minetest.get_meta(pos)
+		return tubelib.put_item(meta, "src", item)
+	end,
+	on_recv_message = function(pos, topic, payload)
+		if topic == "on" then
+			return start_the_machine(pos)
+		elseif topic == "off" then
+			return stop_the_machine(pos)
+		elseif topic == "state" then
+			local meta = minetest.get_meta(pos)
+			local running = meta:get_int("running")
+			return tubelib.statestring(running)
+		else
+			return "unsupported"
+		end
+	end,
+})	
+--------------------------------------------------------------- tubelib

tubelib/init.lua

@@ -0,0 +1,95 @@
+--[[
+
+	Tube Library
+	============
+
+	Copyright (C) 2017 Joachim Stolberg
+
+	LGPLv2.1+
+	See LICENSE.txt for more information
+
+	History:
+	2017-09-08  v0.01  first version
+	2017-09-12  v0.02  bugfix in tubelib.get_pos() and others
+	2017-09-21  v0.03  function get_num_items added
+	2017-09-26  v0.04  param side added, node blackhole added
+	2017-10-06  v0.05  Parameter 'player_name' added, furnace fuel detection changed
+	2017-10-08  v0.06  tubelib.get_node_number() added, tubelib.version added
+	2017-10-29  v0.07  Pusher bugfix, commands start/stop replaced by on/off
+	2017-11-02  v0.08  Data base changed, aging of node positions added
+	2017-11-04  v0.09  functions set_data/get_data added
+	2018-01-27  v0.10  WLAN Chip added, recipes reviced, Pusher state 'blocked' added, 
+                     function send_request changed
+	
+]]--
+
+
+tubelib = {
+	NodeDef = {},		-- node registration info
+}
+
+tubelib.version = 0.10
+
+
+--------------------------- conversion to v0.04
+minetest.register_lbm({
+	label = "[Tubelib] Distributor update",
+	name = "tubelib:update",
+	nodenames = {"tubelib:distributor", "tubelib:distributor_active"},
+	run_at_every_load = false,
+	action = function(pos, node)
+		local meta = minetest.get_meta(pos)
+		if minetest.deserialize(meta:get_string("filter")) == nil then
+			local filter = {false,false,false,false}
+			meta:set_string("filter", minetest.serialize(filter))
+		end
+		local inv = meta:get_inventory()
+		inv:set_size('yellow', 6)
+		inv:set_size('green', 6)
+		inv:set_size('red', 6)
+		inv:set_size('blue', 6)
+	end
+})
+
+--------------------------- conversion to v0.10
+minetest.register_lbm({
+	label = "[Tubelib] Button update",
+	name = "tubelib:update2",
+	nodenames = {"tubelib:button", "tubelib:button_active"},
+	run_at_every_load = false,
+	action = function(pos, node)
+		local meta = minetest.get_meta(pos)
+		local number = meta:get_string("number")
+		if number ~= "" then
+			meta:set_string("numbers", number)
+			meta:set_string("number", nil)
+		end
+	end
+})
+
+minetest.register_craftitem("tubelib:wlanchip", {
+	description = "Tubelib WLAN Chip",
+	inventory_image = "tubelib_wlanchip.png",
+})
+
+
+minetest.register_craft({
+	output = "tubelib:wlanchip 8",
+	recipe = {
+		{"default:mese_crystal", "default:copper_ingot", ""},
+		{"default:gold_ingot",   "default:glass",	""},
+		{"", "", ""},
+	},
+})
+
+
+dofile(minetest.get_modpath("tubelib") .. "/tubes.lua")
+dofile(minetest.get_modpath("tubelib") .. "/command.lua")
+dofile(minetest.get_modpath("tubelib") .. "/states.lua")
+dofile(minetest.get_modpath("tubelib") .. "/pusher.lua")
+dofile(minetest.get_modpath("tubelib") .. "/blackhole.lua")
+dofile(minetest.get_modpath("tubelib") .. "/button.lua")
+dofile(minetest.get_modpath("tubelib") .. "/lamp.lua")
+dofile(minetest.get_modpath("tubelib") .. "/distributor.lua")
+dofile(minetest.get_modpath("tubelib") .. "/legacy_nodes.lua")
+

tubelib/lamp.lua

@@ -0,0 +1,106 @@
+--[[
+
+	Tube Library
+	============
+
+	Copyright (C) 2017 Joachim Stolberg
+
+	LGPLv2.1+
+	See LICENSE.txt for more information
+
+	lamp.lua:
+	
+	Example of a simple communication node, only receiving messages from others.
+	This node claims a position number and registers its message interface.
+	The Lamp supports the following messages:
+	 - topic = "on", payload  = nil
+	 - topic = "off" , payload  = nil
+
+]]--
+
+local function switch_on(pos, node)
+	node.name = "tubelib:lamp_on"
+	minetest.swap_node(pos, node)
+end	
+
+local function switch_off(pos, node)
+	node.name = "tubelib:lamp"
+	minetest.swap_node(pos, node)
+end	
+
+minetest.register_node("tubelib:lamp", {
+	description = "Tubelib Lamp",
+	tiles = {
+		'tubelib_lamp.png',
+	},
+
+	after_place_node = function(pos, placer)
+		local number = tubelib.add_node(pos, "tubelib:lamp")  -- <<=== tubelib
+		local meta = minetest.get_meta(pos)
+		meta:set_string("infotext", "Tubelib Lamp "..number)
+	end,
+
+	on_rightclick = function(pos, node, clicker)
+		if not minetest.is_protected(pos, clicker:get_player_name()) then
+			switch_on(pos, node)
+		end
+	end,
+
+	after_dig_node = function(pos)
+		tubelib.remove_node(pos)  -- <<=== tubelib
+	end,
+
+	paramtype = "light",
+	light_source = 0,	
+	sunlight_propagates = true,
+	paramtype2 = "facedir",
+	groups = {choppy=2, cracky=2, crumbly=2},
+	is_ground_content = false,
+	sounds = default.node_sound_wood_defaults(),
+})
+
+minetest.register_node("tubelib:lamp_on", {
+	description = "Tubelib Lamp",
+	tiles = {
+		'tubelib_lamp.png',
+	},
+
+	on_rightclick = function(pos, node, clicker)
+		if not minetest.is_protected(pos, clicker:get_player_name()) then
+			switch_off(pos, node)
+		end
+	end,
+
+	paramtype = "light",
+	light_source = LIGHT_MAX,	
+	sunlight_propagates = true,
+	paramtype2 = "facedir",
+	groups = {crumbly=0, not_in_creative_inventory=1},
+	is_ground_content = false,
+	sounds = default.node_sound_wood_defaults(),
+})
+
+minetest.register_craft({
+	output = "tubelib:lamp 4",
+	recipe = {
+		{"wool:white",       "wool:white",        "wool:white"},
+		{"tubelib:wlanchip", "default:coal_lump", ""},
+		{"group:wood",       "",                  "group:wood"},
+	},
+})
+
+--------------------------------------------------------------- tubelib
+tubelib.register_node("tubelib:lamp", {"tubelib:lamp_on"}, {
+	on_pull_item = nil,			-- lamp has no inventory
+	on_push_item = nil,			-- lamp has no inventory
+	on_unpull_item = nil,		-- lamp has no inventory
+	on_recv_message = function(pos, topic, payload)
+		local node = minetest.get_node(pos)
+		if topic == "on" then
+			switch_on(pos, node)
+		elseif topic == "off" then
+			switch_off(pos, node)
+		end
+	end,
+})		
+--------------------------------------------------------------- tubelib

tubelib/legacy_nodes.lua

@@ -0,0 +1,107 @@
+--[[
+
+	Tube Library
+	============
+
+	Copyright (C) 2017 Joachim Stolberg
+
+	LGPLv2.1+
+	See LICENSE.txt for more information
+
+	legacy_nodes.lua:
+	
+	Tubelib support for chests and furnace
+	
+]]--
+
+tubelib.register_node("default:chest", {"default:chest_open"}, {
+	on_pull_item = function(pos, side)
+		local meta = minetest.get_meta(pos)
+		return tubelib.get_item(meta, "main")
+	end,
+	on_push_item = function(pos, side, item)
+		local meta = minetest.get_meta(pos)
+		return tubelib.put_item(meta, "main", item)
+	end,
+	on_unpull_item = function(pos, side, item)
+		local meta = minetest.get_meta(pos)
+		return tubelib.put_item(meta, "main", item)
+	end,
+})	
+
+
+tubelib.register_node("default:chest_locked", {"default:chest_locked_open"}, {
+	on_pull_item = function(pos, side, player_name)
+		local meta = minetest.get_meta(pos)
+		local owner = meta:get_string("owner")
+		if player_name == owner or player_name == "" then
+			return tubelib.get_item(meta, "main")
+		end
+		return nil
+	end,
+	on_push_item = function(pos, side, item, player_name)
+		local meta = minetest.get_meta(pos)
+		local owner = meta:get_string("owner")
+		if player_name == owner or player_name == "" then
+			return tubelib.put_item(meta, "main", item)
+		end
+		return false
+	end,
+	on_unpull_item = function(pos, side, item, player_name)
+		local meta = minetest.get_meta(pos)
+		local owner = meta:get_string("owner")
+		if player_name == owner or player_name == "" then
+			return tubelib.put_item(meta, "main", item)
+		end
+		return nil
+	end,
+})	
+
+tubelib.register_node("default:furnace", {"default:furnace_active"}, {
+	on_pull_item = function(pos, side)
+		local meta = minetest.get_meta(pos)
+		return tubelib.get_item(meta, "dst")
+	end,
+	on_push_item = function(pos, side, item)
+		local meta = minetest.get_meta(pos)
+		minetest.get_node_timer(pos):start(1.0)
+		if minetest.get_craft_result({method="fuel", width=1, items={item}}).time ~= 0 then
+			return tubelib.put_item(meta, "fuel", item)
+		else
+			return tubelib.put_item(meta, "src", item)
+		end
+	end,
+	on_unpull_item = function(pos, side, item)
+		local meta = minetest.get_meta(pos)
+		return tubelib.put_item(meta, "dst", item)
+	end,
+})	
+
+tubelib.register_node("shop:shop", {}, {
+	on_pull_item = function(pos, side, player_name)
+		local meta = minetest.get_meta(pos)
+		local owner = meta:get_string("owner")
+		if player_name == owner or player_name == "" then
+			return tubelib.get_item(meta, "register")
+		end
+		return nil
+	end,
+	on_push_item = function(pos, side, item, player_name)
+		local meta = minetest.get_meta(pos)
+		local owner = meta:get_string("owner")
+		if player_name == owner or player_name == "" then
+			return tubelib.put_item(meta, "stock", item)
+		end
+		return false
+	end,
+	on_unpull_item = function(pos, side, item, player_name)
+		local meta = minetest.get_meta(pos)
+		local owner = meta:get_string("owner")
+		if player_name == owner or player_name == "" then
+			return tubelib.put_item(meta, "register", item)
+		end
+		return nil
+	end,
+})	
+
+

tubelib/manual.md

@@ -0,0 +1,39 @@
+# Tubelib Library
+
+## Hints for Admins and Players
+
+Tubelib is little useful for itself, it makes only sense with extensions such as:  
+- ![tubelib_addons1](https://github.com/joe7575/tubelib_addons1) with farming nodes like Harvester, Quarry, Grinder, Autocrafter, Fermenter and Reformer.
+- ![tubelib_addons2](https://github.com/joe7575/tubelib_addons2) with control task nodes like Timer, Sequencer, Repeater, Gate, Door, Access Lock and Color Lamp.
+
+However Tubelib provides the following basic nodes:
+
+### Tubes
+Tubes allow the item exchange between two nodes. Tube forks are not possible. You have to use chests 
+or other inventory nodes as hubs to build more complex structures.
+Tubes for itself are passive. For item exchange you have to use pulling/pushing nodes in addition.
+The maximum tube length is limited to 100 nodes.
+
+### Pusher
+The Pusher is able to pull one item out of one inventory node and pushing it into another inventory node directly or by means of tubes.
+It the source node is empty or the destination node full, the Pusher goes into STANDBY state for some seconds.
+
+### Distributor
+The Distributor works as filter and pusher. It allows to divide and distribute incoming items into 4 tube channels.
+The channels can be switched on/off and individually configured with up to 6 items. The filter passes the configured
+items and restrains all others. To increase the throughput, one item can be added several times to a filter.
+An unconfigured but activated filter allows to pass up to 6 remaining items.
+
+### Button/Switch
+The Button/Switch is a simple communication node for the Tubelib wireless communication.
+This node can be configured as button and switch. For the button configuration different switching
+times from 2 to 16 seconds are possible. The Button/Switch node has to be configured with the destination
+number of the receiving node (e.g. Lamp). This node allows to address several receivers by means or their numbers.
+All numbers of the receiving nodes have to be added a configuration time.
+
+### Lamp
+The Lamp is a receiving node, showing its destination/communication number via "infotext".
+The Lamp can be switched on/off by means of the right mouse button (use function) or by means of messages commands
+from a Button/Switch or any other command sending node.
+
+

tubelib/mod.conf

@@ -0,0 +1 @@
+name=tubelib

tubelib/pusher.lua

@@ -0,0 +1,243 @@
+--[[
+
+	Tube Library
+	============
+
+	Copyright (C) 2017 Joachim Stolberg
+
+	LGPLv2.1+
+	See LICENSE.txt for more information
+
+	pusher.lua:
+	
+	Simple node for push/pull operation of StackItems from chests or other
+	inventory/server nodes to tubes or other inventory/server nodes.
+	
+	The Pusher supports the following messages:
+	 - topic = "on", payload  = nil
+	 - topic = "off", payload  = nil
+	 - topic = "state", payload  = nil, 
+	   response is "running", "stopped", "standby", "blocked", or "not supported"
+
+]]--
+
+--                 +--------+
+--                /        /|
+--               +--------+ |
+--     IN (L) -->|        |x--> OUT (R)
+--               | PUSHER | +
+--               |        |/
+--               +--------+
+
+local RUNNING_STATE = 10 
+
+local function switch_on(pos, node)
+	local meta = minetest.get_meta(pos)
+	local number = meta:get_string("number")
+	meta:set_int("running", RUNNING_STATE)
+	meta:set_string("infotext", "Pusher "..number..": running")
+	node.name = "tubelib:pusher_active"
+	minetest.swap_node(pos, node)
+	minetest.get_node_timer(pos):start(2)
+	return false
+end	
+
+local function switch_off(pos, node)
+	local meta = minetest.get_meta(pos)
+	local number = meta:get_string("number")
+	meta:set_int("running", tubelib.STATE_STOPPED)
+	meta:set_string("infotext", "Pusher "..number..": stopped")
+	node.name = "tubelib:pusher"
+	minetest.swap_node(pos, node)
+	minetest.get_node_timer(pos):stop()
+	return false
+end	
+
+local function goto_standby(pos, node)
+	local meta = minetest.get_meta(pos)
+	local number = meta:get_string("number")
+	meta:set_int("running", tubelib.STATE_STANDBY)
+	meta:set_string("infotext", "Pusher "..number..": standby")
+	node.name = "tubelib:pusher"
+	minetest.swap_node(pos, node)
+	minetest.get_node_timer(pos):start(20)
+	return false
+end	
+
+local function goto_blocked(pos, node)
+	local meta = minetest.get_meta(pos)
+	local number = meta:get_string("number")
+	meta:set_int("running", tubelib.STATE_BLOCKED)
+	meta:set_string("infotext", "Pusher "..number..": blocked")
+	node.name = "tubelib:pusher"
+	minetest.swap_node(pos, node)
+	minetest.get_node_timer(pos):start(20)
+	return false
+end	
+
+local function keep_running(pos, elapsed)
+	local meta = minetest.get_meta(pos)
+	local number = meta:get_string("number")
+	local running = meta:get_int("running") - 1
+	local player_name = meta:get_string("player_name")
+	local items = tubelib.pull_items(pos, "L", player_name) -- <<=== tubelib
+	if items ~= nil then
+		if tubelib.push_items(pos, "R", items, player_name) == false then -- <<=== tubelib
+			-- place item back
+			tubelib.unpull_items(pos, "L", items, player_name) -- <<=== tubelib
+			local node = minetest.get_node(pos)
+			return goto_blocked(pos, node)
+		end
+		if running <= 0 then
+			local node = minetest.get_node(pos)
+			return switch_on(pos, node)
+		else
+			-- reload running state
+			running = RUNNING_STATE
+		end
+	else
+		if running <= 0 then
+			local node = minetest.get_node(pos)
+			return goto_standby(pos, node)
+		end
+	end
+	meta:set_int("running", running)
+	return true
+end
+
+minetest.register_node("tubelib:pusher", {
+	description = "Tubelib Pusher",
+	tiles = {
+		-- up, down, right, left, back, front
+		'tubelib_pusher1.png',
+		'tubelib_pusher1.png',
+		'tubelib_outp.png',
+		'tubelib_inp.png',
+		"tubelib_pusher1.png^[transformR180]",
+		"tubelib_pusher1.png",
+	},
+
+	after_place_node = function(pos, placer)
+		local meta = minetest.get_meta(pos)
+		meta:set_string("player_name", placer:get_player_name())
+		local number = tubelib.add_node(pos, "tubelib:pusher") -- <<=== tubelib
+		meta:set_string("number", number)
+		meta:set_string("infotext", "Pusher "..number..": stopped")
+	end,
+
+	on_rightclick = function(pos, node, clicker)
+		if not minetest.is_protected(pos, clicker:get_player_name()) then
+			switch_on(pos, node)
+		end
+	end,
+
+	after_dig_node = function(pos)
+		tubelib.remove_node(pos) -- <<=== tubelib
+	end,
+	
+	on_timer = keep_running,
+
+	paramtype = "light",
+	sunlight_propagates = true,
+	paramtype2 = "facedir",
+	groups = {choppy=2, cracky=2, crumbly=2},
+	is_ground_content = false,
+	sounds = default.node_sound_wood_defaults(),
+})
+
+
+minetest.register_node("tubelib:pusher_active", {
+	description = "Tubelib Pusher",
+	tiles = {
+		-- up, down, right, left, back, front
+		{
+			image = "tubelib_pusher.png",
+			backface_culling = false,
+			animation = {
+				type = "vertical_frames",
+				aspect_w = 32,
+				aspect_h = 32,
+				length = 2.0,
+			},
+		},
+		{
+			image = "tubelib_pusher.png",
+			backface_culling = false,
+			animation = {
+				type = "vertical_frames",
+				aspect_w = 32,
+				aspect_h = 32,
+				length = 2.0,
+			},
+		},
+		'tubelib_outp.png',
+		'tubelib_inp.png',
+		{
+			image = "tubelib_pusher.png^[transformR180]",
+			backface_culling = false,
+			animation = {
+				type = "vertical_frames",
+				aspect_w = 32,
+				aspect_h = 32,
+				length = 2.0,
+			},
+		},
+		{
+			image = "tubelib_pusher.png",
+			backface_culling = false,
+			animation = {
+				type = "vertical_frames",
+				aspect_w = 32,
+				aspect_h = 32,
+				length = 2.0,
+			},
+		},
+	},
+
+	on_rightclick = function(pos, node, clicker)
+		if not minetest.is_protected(pos, clicker:get_player_name()) then
+			switch_off(pos, node)
+		end
+	end,
+	
+	on_timer = keep_running,
+	
+	paramtype = "light",
+	sunlight_propagates = true,
+	paramtype2 = "facedir",
+	groups = {crumbly=0, not_in_creative_inventory=1},
+	is_ground_content = false,
+	sounds = default.node_sound_wood_defaults(),
+})
+
+minetest.register_craft({
+	output = "tubelib:pusher 2",
+	recipe = {
+		{"group:wood", 		"wool:dark_green",   	"group:wood"},
+		{"tubelib:tube1", 	"default:mese_crystal",	"tubelib:tube1"},
+		{"group:wood", 		"wool:dark_green",   	"group:wood"},
+	},
+})
+
+--------------------------------------------------------------- tubelib
+tubelib.register_node("tubelib:pusher", {"tubelib:pusher_active"}, {
+	on_pull_item = nil,  		-- pusher has no inventory
+	on_push_item = nil,			-- pusher has no inventory
+	on_unpull_item = nil,		-- pusher has no inventory
+	
+	on_recv_message = function(pos, topic, payload)
+		local node = minetest.get_node(pos)
+		if topic == "on" then
+			return switch_on(pos, node)
+		elseif topic == "off" then
+			return switch_off(pos, node)
+		elseif topic == "state" then
+			local meta = minetest.get_meta(pos)
+			local running = meta:get_int("running") or tubelib.STATE_STOPPED
+			return tubelib.statestring(running)
+		else
+			return "not supported"
+		end
+	end,
+})	
+--------------------------------------------------------------- tubelib

tubelib/states.lua

@@ -0,0 +1,80 @@
+--[[
+
+	Tube Library
+	============
+
+	Copyright (C) 2017 Joachim Stolberg
+
+	LGPLv2.1+
+	See LICENSE.txt for more information
+
+	states.lua:
+
+	A state model for tubelib nodes.
+
+]]--
+
+--
+-- Inventory Button States
+--
+
+tubelib.STOPPED = 1		-- not operational
+tubelib.RUNNING = 2		-- in normal operation
+tubelib.STANDBY = 3		-- nothing to do or blocked anyhow
+tubelib.FAULT   = 4		-- any fault state, which has to be fixed by the player
+
+tubelib.StatesImg = {
+	"tubelib_inv_button_off.png", 
+	"tubelib_inv_button_on.png", 
+	"tubelib_inv_button_standby.png", 
+	"tubelib_inv_button_error.png"
+}
+			
+-- Return state button image for the node inventory
+function tubelib.state_button(state)
+	if state and state < 5 and state > 0 then
+		return tubelib.StatesImg[state]
+	end
+	return tubelib.StatesImg[tubelib.FAULT]
+end
+			
+
+--
+-- 'running' variable States
+--
+
+tubelib.STATE_RUNNING = 1		-- in normal operation
+tubelib.STATE_STOPPED = 0		-- not operational
+tubelib.STATE_STANDBY = -1		-- nothing to do
+tubelib.STATE_BLOCKED = -2		-- pushing node is blocked due to a full inventory
+tubelib.STATE_FAULT   = -3		-- any fault state, which has to be fixed by the player
+
+-- Return machine state based on the running counter
+function tubelib.state(running)
+	if running > 0 then
+		return tubelib.RUNNING
+	elseif running == 0 then
+		return tubelib.STOPPED
+	elseif running == -1 then
+		return tubelib.STANDBY
+	elseif running == -2 then
+		return tubelib.BLOCKED
+	else
+		return tubelib.FAULT
+	end
+end
+
+-- Return state string based on the running counter
+function tubelib.statestring(running)
+	if running > 0 then
+		return "running"
+	elseif running == 0 then
+		return "stopped"
+	elseif running == -1 then
+		return "standby"
+	elseif running == -2 then
+		return "blocked"
+	else
+		return "fault"
+	end
+end