NodeMetaRef:{to,from}_table and lua_api.txt additions

doc/lua_api.txt

@@ -278,6 +278,8 @@ param2 is reserved for the engine when any of these are used:
   ^ The rotation of the node is stored in param2. Furnaces and chests are
     rotated this way. Can be made by using minetest.dir_to_facedir().
 
+Nodes can also contain extra data. See "Node Metadata".
+
 Representations of simple things
 --------------------------------
 Position/vector:
@@ -548,6 +550,91 @@ time_from_last_punch, tool_capabilities, direction)''.
   * If ''direction'' is nil and ''puncher'' is not nil, ''direction'' will be
     automatically filled in based on the location of ''puncher''.
 
+Node Metadata
+-------------
+The instance of a node in the world normally only contains the three values
+mentioned in "Nodes". However, it is possible to insert extra data into a
+node. It is called "node metadata"; See "NodeMetaRef".
+
+Metadata contains two things:
+- A key-value store
+- An inventory
+
+Some of the values in the key-value store are handled specially:
+- formspec: Defines a right-click inventory menu. See "Formspec".
+- infotext: Text shown on the screen when the node is pointed at
+
+Example stuff:
+
+local meta = minetest.env:get_meta(pos)
+meta:set_string("formspec",
+        "invsize[8,9;]"..
+        "list[current_name;main;0,0;8,4;]"..
+        "list[current_player;main;0,5;8,4;]")
+meta:set_string("infotext", "Chest");
+local inv = meta:get_inventory()
+inv:set_size("main", 8*4)
+print(dump(meta:to_table()))
+meta:from_table({
+    inventory = {
+        main = {[1] = "default:dirt", [2] = "", [3] = "", [4] = "", [5] = "", [6] = "", [7] = "", [8] = "", [9] = "", [10] = "", [11] = "", [12] = "", [13] = "", [14] = "default:cobble", [15] = "", [16] = "", [17] = "", [18] = "", [19] = "", [20] = "default:cobble", [21] = "", [22] = "", [23] = "", [24] = "", [25] = "", [26] = "", [27] = "", [28] = "", [29] = "", [30] = "", [31] = "", [32] = ""}
+    },
+    fields = {
+        formspec = "invsize[8,9;]list[current_name;main;0,0;8,4;]list[current_player;main;0,5;8,4;]",
+        infotext = "Chest"
+    }
+})
+
+Formspec
+--------
+Formspec defines a menu. Currently not much else than inventories are
+supported. It is a string, with a somewhat strange format.
+
+Spaces and newlines can be inserted between the blocks, as is used in the
+examples.
+
+Examples:
+- Chest:
+    invsize[8,9;]
+    list[current_name;main;0,0;8,4;]
+    list[current_player;main;0,5;8,4;]
+- Furnace:
+    invsize[8,9;]
+    list[current_name;fuel;2,3;1,1;]
+    list[current_name;src;2,1;1,1;]
+    list[current_name;dst;5,1;2,2;]
+    list[current_player;main;0,5;8,4;]
+
+Elements:
+
+invsize[<W>,<H>;]
+^ Define the size of the menu in inventory slots
+
+list[<inventory location>;<list name>;<X>,<Y>;<W>,<H>;]
+^ Show an inventory list
+
+image[<X>,<Y>;<W>,<H>;<texture name>]
+^ Show an image
+^ Position and size units are inventory slots
+^ Not implemented
+
+field[<X>,<Y>;<W>,<H>;<name>;<label>;<default>]
+^ Textual field; will be sent to server when a button is clicked
+^ Position and size units are inventory slots
+^ Not implemented
+
+button[<X>,<Y>;<W>,<H>;<name>;<label>]
+^ Clickable button. When clicked, fields will be sent.
+^ Button will be visible as a field, with the value "active".
+^ Position and size units are inventory slots
+^ Not implemented
+
+Inventory location:
+- "current_name": Selected node metadata
+- "current_player": Player to whom the menu is shown
+- "player:<name>": Any player
+- "nodemeta:<X>,<Y>,<Z>": Any node metadata
+
 Helper functions
 -----------------
 dump2(obj, name="_", dumped={})
@@ -766,7 +853,9 @@ Deprecated:
 - add_rat(pos): Add C++ rat object (no-op)
 - add_firefly(pos): Add C++ firefly object (no-op)
 
-NodeMetaRef (this stuff is subject to change in a future version)
+NodeMetaRef: Node metadata - reference extra data and functionality stored
+             in a node
+- Can be gotten via minetest.env:get_nodemeta(pos)
 methods:
 - set_string(name, value)
 - get_string(name)
@@ -775,6 +864,9 @@ methods:
 - set_float(name, value)
 - get_float(name)
 - get_inventory() -> InvRef
+- to_table() -> nil or {fields = {...}, inventory = {list1 = {}, ...}}
+- from_table(nil or {})
+  ^ See "Node Metadata"
 
 ObjectRef: Moving things in the game are generally these
 (basically reference to a C++ ServerActiveObject)

src/inventory.cpp

@@ -915,6 +915,17 @@ InventoryList * Inventory::getList(const std::string &name)
 	return m_lists[i];
 }
 
+std::vector<const InventoryList*> Inventory::getLists()
+{
+	std::vector<const InventoryList*> lists;
+	for(u32 i=0; i<m_lists.size(); i++)
+	{
+		InventoryList *list = m_lists[i];
+		lists.push_back(list);
+	}
+	return lists;
+}
+
 bool Inventory::deleteList(const std::string &name)
 {
 	s32 i = getListIndex(name);

src/inventory.h

@@ -262,6 +262,7 @@ public:
 	InventoryList * addList(const std::string &name, u32 size);
 	InventoryList * getList(const std::string &name);
 	const InventoryList * getList(const std::string &name) const;
+	std::vector<const InventoryList*> getLists();
 	bool deleteList(const std::string &name);
 	// A shorthand for adding items. Returns leftover item (possibly empty).
 	ItemStack addItem(const std::string &listname, const ItemStack &newitem)

src/map.cpp

@@ -1009,6 +1009,12 @@ void Map::addNodeAndUpdate(v3s16 p, MapNode n,
 		n.setLight(LIGHTBANK_DAY, LIGHT_SUN, nodemgr);
 	}
 
+	/*
+		Remove node metadata
+	*/
+
+	removeNodeMetadata(p);
+
 	/*
 		Set the node on the map
 	*/
@@ -3451,15 +3457,15 @@ MapBlock* ServerMap::loadBlock(v3s16 blockpos)
 		}
 		catch(InvalidFilenameException &e)
 		{
-			return false;
+			return NULL;
 		}
 		catch(FileNotGoodException &e)
 		{
-			return false;
+			return NULL;
 		}
 		catch(std::exception &e)
 		{
-			return false;
+			return NULL;
 		}
 	}
 	

src/nodemetadata.h

@@ -64,6 +64,10 @@ public:
 		else
 			m_stringvars[name] = var;
 	}
+	std::map<std::string, std::string> getStrings() const
+	{
+		return m_stringvars;
+	}
 
 	// The inventory
 	Inventory* getInventory()

src/scriptapi.cpp

@@ -1233,6 +1233,8 @@ static void inventory_get_list_to_lua(Inventory *inv, const char *name,
 		if(lua_pcall(L, 2, 0, 0))
 			script_error(L, "error: %s", lua_tostring(L, -1));
 	}
+	lua_remove(L, -2); // Remove table
+	lua_remove(L, -2); // Remove insert
 }
 
 /*
@@ -2088,97 +2090,90 @@ private:
 		return 1;
 	}
 	
-	// get_inventory_draw_spec(self)
+	// to_table(self)
-	static int l_get_inventory_draw_spec(lua_State *L)
+	static int l_to_table(lua_State *L)
 	{
 		NodeMetaRef *ref = checkobject(L, 1);
 
-		NodeMetadata *meta = getmeta(ref, false);
+		NodeMetadata *meta = getmeta(ref, true);
 		if(meta == NULL){
-			lua_pushlstring(L, "", 0);
+			lua_pushnil(L);
 			return 1;
 		}
-		std::string str = meta->getString("formspec");
+		lua_newtable(L);
-		lua_pushlstring(L, str.c_str(), str.size());
+		// fields
+		lua_newtable(L);
+		{
+			std::map<std::string, std::string> fields = meta->getStrings();
+			for(std::map<std::string, std::string>::const_iterator
+					i = fields.begin(); i != fields.end(); i++){
+				const std::string &name = i->first;
+				const std::string &value = i->second;
+				lua_pushlstring(L, name.c_str(), name.size());
+				lua_pushlstring(L, value.c_str(), value.size());
+				lua_settable(L, -3);
+			}
+		}
+		lua_setfield(L, -2, "fields");
+		// inventory
+		lua_newtable(L);
+		Inventory *inv = meta->getInventory();
+		if(inv){
+			std::vector<const InventoryList*> lists = inv->getLists();
+			for(std::vector<const InventoryList*>::const_iterator
+					i = lists.begin(); i != lists.end(); i++){
+				inventory_get_list_to_lua(inv, (*i)->getName().c_str(), L);
+				lua_setfield(L, -2, (*i)->getName().c_str());
+			}
+		}
+		lua_setfield(L, -2, "inventory");
 		return 1;
 	}
 
-	// set_inventory_draw_spec(self, text)
+	// from_table(self, table)
-	static int l_set_inventory_draw_spec(lua_State *L)
+	static int l_from_table(lua_State *L)
 	{
 		NodeMetaRef *ref = checkobject(L, 1);
-		size_t len = 0;
+		int base = 2;
-		const char *s = lua_tolstring(L, 2, &len);
-		std::string str(s, len);
 		
-		NodeMetadata *meta = getmeta(ref, !str.empty());
+		if(lua_isnil(L, base)){
-		if(meta == NULL || str == meta->getString("formspec"))
+			// No metadata
-			return 0;
+			ref->m_env->getMap().removeNodeMetadata(ref->m_p);
-		meta->setString("formspec",str);
+			lua_pushboolean(L, true);
-		reportMetadataChange(ref);
-		return 0;
-	}
-
-	// get_form_spec(self)
-	static int l_get_form_spec(lua_State *L)
-	{
-		NodeMetaRef *ref = checkobject(L, 1);
-
-		NodeMetadata *meta = getmeta(ref, false);
-		if(meta == NULL){
-			lua_pushlstring(L, "", 0);
 			return 1;
 		}
-		std::string str = meta->getString("formspec");
-		lua_pushlstring(L, str.c_str(), str.size());
-		return 1;
-	}
 
-	// set_form_spec(self, text)
+		// Has metadata; clear old one first
-	static int l_set_form_spec(lua_State *L)
+		ref->m_env->getMap().removeNodeMetadata(ref->m_p);
-	{
+		// Create new metadata
-		NodeMetaRef *ref = checkobject(L, 1);
+		NodeMetadata *meta = getmeta(ref, true);
-		size_t len = 0;
+		// Set fields
-		const char *s = lua_tolstring(L, 2, &len);
+		lua_getfield(L, base, "fields");
-		std::string str(s, len);
+		int fieldstable = lua_gettop(L);
-
+		lua_pushnil(L);
-		NodeMetadata *meta = getmeta(ref, !str.empty());
+		while(lua_next(L, fieldstable) != 0){
-		if(meta == NULL || str == meta->getString("formspec"))
+			// key at index -2 and value at index -1
-			return 0;
+			std::string name = lua_tostring(L, -2);
-		meta->setString("formspec",str);
+			size_t cl;
-		reportMetadataChange(ref);
+			const char *cs = lua_tolstring(L, -1, &cl);
-		return 0;
+			std::string value(cs, cl);
-	}
+			meta->setString(name, value);
-
+			lua_pop(L, 1); // removes value, keeps key for next iteration
-	// get_infotext(self)
+		}
-	static int l_get_infotext(lua_State *L)
+		// Set inventory
-	{
+		Inventory *inv = meta->getInventory();
-		NodeMetaRef *ref = checkobject(L, 1);
+		lua_getfield(L, base, "inventory");
-
+		int inventorytable = lua_gettop(L);
-		NodeMetadata *meta = getmeta(ref, false);
+		lua_pushnil(L);
-		if(meta == NULL){
+		while(lua_next(L, inventorytable) != 0){
-			lua_pushlstring(L, "", 0);
+			// key at index -2 and value at index -1
-			return 1;
+			std::string name = lua_tostring(L, -2);
+			inventory_set_list_from_lua(inv, name.c_str(), L, -1);
+			lua_pop(L, 1); // removes value, keeps key for next iteration
 		}
-		std::string str = meta->getString("infotext");
-		lua_pushlstring(L, str.c_str(), str.size());
-		return 1;
-	}
-
-	// set_infotext(self, text)
-	static int l_set_infotext(lua_State *L)
-	{
-		NodeMetaRef *ref = checkobject(L, 1);
-		size_t len = 0;
-		const char *s = lua_tolstring(L, 2, &len);
-		std::string str(s, len);
-
-		NodeMetadata *meta = getmeta(ref, !str.empty());
-		if(meta == NULL || str == meta->getString("infotext"))
-			return 0;
-		meta->setString("infotext",str);
 		reportMetadataChange(ref);
-		return 0;
+		lua_pushboolean(L, true);
+		return 1;
 	}
 
 public:
@@ -2240,12 +2235,8 @@ const luaL_reg NodeMetaRef::methods[] = {
 	method(NodeMetaRef, get_float),
 	method(NodeMetaRef, set_float),
 	method(NodeMetaRef, get_inventory),
-	method(NodeMetaRef, get_inventory_draw_spec),
+	method(NodeMetaRef, to_table),
-	method(NodeMetaRef, set_inventory_draw_spec),
+	method(NodeMetaRef, from_table),
-	method(NodeMetaRef, get_form_spec),
-	method(NodeMetaRef, set_form_spec),
-	method(NodeMetaRef, get_infotext),
-	method(NodeMetaRef, set_infotext),
 	{0,0}
 };