Add node on_construct, on_destruct callbacks and update lua_api.txt

doc/lua_api.txt

@@ -775,18 +775,13 @@ methods:
 - get_owner()
 - set_owner(string)
 Generic node metadata specific:
-- set_infotext(infotext)
-- get_inventory() -> InvRef
-- set_inventory_draw_spec(string)
-- set_allow_text_input(bool)
-- set_allow_removal(bool)
-- set_enforce_owner(bool)
-- is_inventory_modified()
-- reset_inventory_modified()
-- is_text_modified()
-- reset_text_modified()
 - set_string(name, value)
 - get_string(name)
+- set_int(name, value)
+- get_int(name)
+- set_float(name, value)
+- get_float(name)
+- get_inventory() -> InvRef
 
 ObjectRef: Moving things in the game are generally these
 (basically reference to a C++ ServerActiveObject)
@@ -983,9 +978,13 @@ Item definition (register_node, register_craftitem, register_tool)
             choppy={times={[3]=0.90}, maxwear=0.05, maxlevel=0}
         }
     }
-    on_drop = func(itemstack, dropper, pos),
+
     on_place = func(itemstack, placer, pointed_thing),
+    ^ default: minetest.item_place
+    on_drop = func(itemstack, dropper, pos),
+    ^ default: minetest.item_drop
     on_use = func(itemstack, user, pointed_thing),
+    ^  default: nil
     ^ Function must return either nil if no item shall be removed from
       inventory, or an itemstack to replace the original itemstack.
         eg. itemstack:take_item(); return itemstack
@@ -1032,6 +1031,19 @@ Node definition (register_node)
         dig = <SimpleSoundSpec>, -- "__group" = group-based sound (default)
         dug = <SimpleSoundSpec>,
     },
+
+    on_construct = func(pos),
+    ^ Node constructor; always called after adding node
+    ^ Can set up metadata and stuff like that
+    on_destruct = func(pos),
+    ^ Node destructor; always called before removing node
+	
+    on_punch = func(pos, node, puncher),
+    ^ default: minetest.node_punch
+    ^ By default: does nothing
+	on_dig = func(pos, node, digger),
+    ^ default: minetest.node_dig
+    ^ By default: checks privileges, wears out tool and removes node
 }
 
 Recipe: (register_craft)

src/scriptapi.cpp

@@ -2978,8 +2978,15 @@ private:
 		// content
 		MapNode n = readnode(L, 3, env->getGameDef()->ndef());
 		// Do it
+		// Call destructor
+		MapNode n_old = env->getMap().getNodeNoEx(pos);
+		scriptapi_node_on_destruct(L, pos, n_old);
+		// Replace node
 		bool succeeded = env->getMap().addNodeWithEvent(pos, n);
 		lua_pushboolean(L, succeeded);
+		// Call constructor
+		if(succeeded)
+			scriptapi_node_on_construct(L, pos, n);
 		return 1;
 	}
 
@@ -2999,8 +3006,13 @@ private:
 		// pos
 		v3s16 pos = read_v3s16(L, 2);
 		// Do it
+		// Call destructor
+		MapNode n = env->getMap().getNodeNoEx(pos);
+		scriptapi_node_on_destruct(L, pos, n);
+		// Replace with air
 		bool succeeded = env->getMap().removeNodeWithEvent(pos);
 		lua_pushboolean(L, succeeded);
+		// Air doesn't require constructor
 		return 1;
 	}
 
@@ -4881,7 +4893,7 @@ bool scriptapi_item_on_use(lua_State *L, ItemStack &item,
 	return true;
 }
 
-bool scriptapi_node_on_punch(lua_State *L, v3s16 pos, MapNode node,
+bool scriptapi_node_on_punch(lua_State *L, v3s16 p, MapNode node,
 		ServerActiveObject *puncher)
 {
 	realitycheck(L);
@@ -4895,7 +4907,7 @@ bool scriptapi_node_on_punch(lua_State *L, v3s16 pos, MapNode node,
 		return false;
 
 	// Call function
-	push_v3s16(L, pos);
+	push_v3s16(L, p);
 	pushnode(L, node, ndef);
 	objectref_get_or_create(L, puncher);
 	if(lua_pcall(L, 3, 0, 0))
@@ -4903,7 +4915,7 @@ bool scriptapi_node_on_punch(lua_State *L, v3s16 pos, MapNode node,
 	return true;
 }
 
-bool scriptapi_node_on_dig(lua_State *L, v3s16 pos, MapNode node,
+bool scriptapi_node_on_dig(lua_State *L, v3s16 p, MapNode node,
 		ServerActiveObject *digger)
 {
 	realitycheck(L);
@@ -4917,7 +4929,7 @@ bool scriptapi_node_on_dig(lua_State *L, v3s16 pos, MapNode node,
 		return false;
 
 	// Call function
-	push_v3s16(L, pos);
+	push_v3s16(L, p);
 	pushnode(L, node, ndef);
 	objectref_get_or_create(L, digger);
 	if(lua_pcall(L, 3, 0, 0))
@@ -4925,6 +4937,42 @@ bool scriptapi_node_on_dig(lua_State *L, v3s16 pos, MapNode node,
 	return true;
 }
 
+void scriptapi_node_on_construct(lua_State *L, v3s16 p, MapNode node)
+{
+	realitycheck(L);
+	assert(lua_checkstack(L, 20));
+	StackUnroller stack_unroller(L);
+
+	INodeDefManager *ndef = get_server(L)->ndef();
+
+	// Push callback function on stack
+	if(!get_item_callback(L, ndef->get(node).name.c_str(), "on_construct"))
+		return;
+
+	// Call function
+	push_v3s16(L, p);
+	if(lua_pcall(L, 1, 0, 0))
+		script_error(L, "error: %s", lua_tostring(L, -1));
+}
+
+void scriptapi_node_on_destruct(lua_State *L, v3s16 p, MapNode node)
+{
+	realitycheck(L);
+	assert(lua_checkstack(L, 20));
+	StackUnroller stack_unroller(L);
+
+	INodeDefManager *ndef = get_server(L)->ndef();
+
+	// Push callback function on stack
+	if(!get_item_callback(L, ndef->get(node).name.c_str(), "on_destruct"))
+		return;
+
+	// Call function
+	push_v3s16(L, p);
+	if(lua_pcall(L, 1, 0, 0))
+		script_error(L, "error: %s", lua_tostring(L, -1));
+}
+
 /*
 	environment
 */

src/scriptapi.h

@@ -81,6 +81,8 @@ bool scriptapi_node_on_punch(lua_State *L, v3s16 p, MapNode node,
 		ServerActiveObject *puncher);
 bool scriptapi_node_on_dig(lua_State *L, v3s16 p, MapNode node,
 		ServerActiveObject *digger);
+void scriptapi_node_on_construct(lua_State *L, v3s16 p, MapNode node);
+void scriptapi_node_on_destruct(lua_State *L, v3s16 p, MapNode node);
 
 /* luaentity */
 // Returns true if succesfully added into Lua; false otherwise.