Wagon iterator, lookup by id, and use them in code

advtrains/trainlogic.lua

@@ -142,15 +142,10 @@ minetest.register_on_joinplayer(function(player)
 		local pname = player:get_player_name()
 		local id=advtrains.player_to_train_mapping[pname]
 		if id then
-			for _,wagon in pairs(minetest.luaentities) do
-				if wagon.is_wagon and wagon.initialized and wagon.id then
-					local wdata = advtrains.wagons[wagon.id]
-					if wdata and wdata.train_id == id then
+			for _, wagon in advtrains.wagon_entity_pairs_in_train(id) do
 				wagon:reattach_all()
 			end
 		end
-			end
-		end
 end)
 
 
@@ -160,13 +155,11 @@ minetest.register_on_dieplayer(function(player)
 		if id then
 			local train=advtrains.trains[id]
 			if not train then advtrains.player_to_train_mapping[pname]=nil return end
-			for _,wagon in pairs(minetest.luaentities) do
-				if wagon.is_wagon and wagon.initialized and wagon.train_id==id then
+			for _, wagon in advtrains.wagon_entity_pairs_in_train(id) do
 				--when player dies, detach him from the train
 				--call get_off_plr on every wagon since we don't know which one he's on.
 				wagon:get_off_plr(pname)
 			end
-			end
 			-- just in case no wagon felt responsible for this player: clear train mapping
 			advtrains.player_to_train_mapping[pname] = nil
 		end

advtrains/wagons.lua

@@ -1103,15 +1103,14 @@ function wagon:handle_bordcom_fields(pname, formname, fields)
 	for i, tpid in ipairs(train.trainparts) do
 		if fields["dcpl_"..i] then
 			advtrains.safe_decouple_wagon(tpid, pname)
-		elseif fields["wgprp"..i] then
-			for _,wagon in pairs(minetest.luaentities) do
-				if wagon.is_wagon and wagon.initialized and wagon.id==tpid and data.owner==pname then
+		elseif fields["wgprp"..i] and data.owner==pname then
+			local wagon = advtrains.get_wagon_entity(tpid)
+			if wagon then
 				wagon:show_wagon_properties(pname)
 				return
 			end
 		end
 	end
-	end
 	--check cpl_eid_front and _back of train
 	local couple_front = checkcouple(train.cpl_front)
 	local couple_back = checkcouple(train.cpl_back)
@@ -1154,8 +1153,8 @@ end
 minetest.register_on_player_receive_fields(function(player, formname, fields)
 		local uid=string.match(formname, "^advtrains_geton_(.+)$")
 		if uid then
-			for _,wagon in pairs(minetest.luaentities) do
-				if wagon.is_wagon and wagon.initialized and wagon.id==uid then
+			local wagon = advtrains.get_wagon_entity(uid)
+			if wagon then
 				local data = advtrains.wagons[wagon.id]
 				if fields.inv then
 					if wagon.has_inventory and wagon.get_inventory_formspec then
@@ -1171,12 +1170,13 @@ minetest.register_on_player_receive_fields(function(player, formname, fields)
 					end
 				end
 			end
+			return true
 		end
-		end
+
 		uid=string.match(formname, "^advtrains_seating_(.+)$")
 		if uid then
-			for _,wagon in pairs(minetest.luaentities) do
-				if wagon.is_wagon and wagon.initialized and wagon.id==uid then
+			local wagon = advtrains.get_wagon_entity(uid)
+			if wagon then
 				local pname=player:get_player_name()
 				local no=wagon:get_seatno(pname)
 				if no then
@@ -1185,13 +1185,16 @@ minetest.register_on_player_receive_fields(function(player, formname, fields)
 					end
 				end
 			end
+			return true
 		end
-		end
+
 		uid=string.match(formname, "^advtrains_prop_(.+)$")
 		if uid then
 			local pname=player:get_player_name()
 			local data = advtrains.wagons[uid]
-			if pname~=data.owner and not minetest.check_player_privs(pname, {train_admin = true}) then
+			if not data then
+				return true
+			elseif pname~=data.owner and not minetest.check_player_privs(pname, {train_admin = true}) then
 				return true
 			end
 			if fields.save or not fields.quit then
@@ -1213,29 +1216,32 @@ minetest.register_on_player_receive_fields(function(player, formname, fields)
 					wagon.show_wagon_properties({id=uid}, pname)
 				end
 			end
+			return true
 		end
 		uid=string.match(formname, "^advtrains_bordcom_(.+)$")
 		if uid then
-			for _,wagon in pairs(minetest.luaentities) do
-				if wagon.is_wagon and wagon.initialized and wagon.id==uid then
+			local wagon = advtrains.get_wagon_entity(uid)
+			if wagon then
 				wagon:handle_bordcom_fields(player:get_player_name(), formname, fields)
 			end
+			return true
 		end
-		end
+
 		uid=string.match(formname, "^advtrains_inv_(.+)$")
 		if uid then
 			local pname=player:get_player_name()
 			local data = advtrains.wagons[uid]
 			if fields.prop and data.owner==pname then
-				for _,wagon in pairs(minetest.luaentities) do
-					if wagon.is_wagon and wagon.initialized and wagon.id==uid and data.owner==pname then
+				local wagon = advtrains.get_wagon_entity(uid)
+				if wagon then
 					wagon:show_wagon_properties(pname)
 					--wagon:handle_bordcom_fields(player:get_player_name(), formname, fields)
 				end
 			end
-			end
+			return true
 		end
 end)
+
 function wagon:seating_from_key_helper(pname, fields, no)
 	local data = advtrains.wagons[self.id]
 	local sgr=self.seats[no].group
@@ -1507,3 +1513,27 @@ function advtrains.get_wagon_at_index(train_id, w_index)
 	-- nothing found, dist must be further back
 	return nil
 end
+
+function advtrains.get_wagon_entity(wagon_id)
+	if not advtrains.wagons[wagon_id] then return end
+	local object = advtrains.wagon_objects[wagon_id]
+	if object then
+		return object:get_luaentity()
+	end
+end
+
+function advtrains.next_wagon_entity_in_train(train, i)
+	local wagon_id = train.trainparts[i + 1]
+	if wagon_id then
+		local wagon = advtrains.get_wagon_entity(wagon_id)
+		if wagon then
+			return i + 1, wagon
+		end
+	end
+end
+
+function advtrains.wagon_entity_pairs_in_train(train_id)
+	local train = advtrains.trains[train_id]
+	if not train then return function() end end
+	return advtrains.next_wagon_entity_in_train, train, 0
+end