Added command based mob spawner node, tidied code

README.txt

@@ -28,6 +28,7 @@ This mod contains the following additions:
 
 Changelog:
 
+1.23- Added mob spawner block for admin to setup spawners in-game (place and right click to enter settings)
 1.22- Added ability to name tamed animals and npc using nametags, also npc will attack anyone who punches them apart from owner
 1.21- Added some more error checking to reduce serialize.h error and added height checks for falling off cliffs (thanks cmdskp)
 1.20- Error checking added to remove bad mobs, out of map limit mobs and stop serialize.h error

api.lua

@@ -1,4 +1,4 @@
--- Mobs Api (31st December 2015)
+-- Mobs Api (4th January 2016)
 mobs = {}
 mobs.mod = "redo"
 
@@ -1833,13 +1833,13 @@ function mobs:spawn_specific(name, nodes, neighbors, min_light, max_light,
 			local mob = minetest.add_entity(pos, name)
 			--local ent = mob:get_luaentity()
 
-			if mob == false then
+			if mob and mob:get_luaentity() then
-				print ("[mobs]" .. name .. " failed to spawn at "
-				.. minetest.pos_to_string(pos))
-			else
 --				print ("[mobs] Spawned " .. name .. " at "
 --				.. minetest.pos_to_string(pos) .. " on "
 --				.. node.name .. " near " .. neighbors[1])
+			else
+				print ("[mobs]" .. name .. " failed to spawn at "
+				.. minetest.pos_to_string(pos))
 			end
 
 		end
@@ -2265,7 +2265,7 @@ function mobs:feed_tame(self, clicker, feed_count, breed, tame)
 
 		local name = clicker:get_player_name()
 
-		-- store mob and nametag stack in external variable
+		-- store mob and nametag stack in external variables
 		mob_obj[name] = self
 		mob_sta[name] = item
 

init.lua

@@ -33,4 +33,7 @@ dofile(path.."/npc.lua") -- TenPlus1
 -- Mob Items
 dofile(path.."/crafts.lua")
 
+-- Spawner
+dofile(path.."/spawner.lua")
+
 print ("[MOD] Mobs Redo loaded")

spawner.lua

@@ -0,0 +1,125 @@
+-- mob spawner
+
+local spawner_default = "mobs:pumba 10 15 0"
+
+minetest.register_node("mobs:spawner", {
+	tiles = {"mob_spawner.png"},
+	drawtype = "glasslike",
+	paramtype = "light",
+	walkable = true,
+	description = "Mob Spawner",
+	groups = {cracky = 1},
+
+	on_construct = function(pos)
+
+		local meta = minetest.get_meta(pos)
+
+		-- text entry formspec
+		meta:set_string("formspec", "field[text;mob_name   min_light   max_light   amount;${command}]")
+		meta:set_string("infotext", "Spawner Not Active (enter settings)")
+		meta:set_string("command", spawner_default)
+	end,
+
+	on_right_click = function(pos, placer)
+		local meta = minetest.get_meta(pos)
+	end,
+
+	on_receive_fields = function(pos, formname, fields, sender)
+
+		if not fields.text or fields.text == "" then
+			return
+		end
+
+		local meta = minetest.get_meta(pos)
+		local comm = fields.text:split(" ")
+		local name = sender:get_player_name()
+
+		if minetest.is_protected(pos, name) then
+			minetest.record_protection_violation(pos, name)
+			return
+		end
+
+		local mob = comm[1]
+		local mlig = tonumber(comm[2])
+		local xlig = tonumber(comm[3])
+		local num = tonumber(comm[4])
+
+		if mob and mob ~= ""
+		and num and num >= 0 and num <= 10
+		and mlig and mlig >= 0 and mlig <= 15
+		and xlig and xlig >= 0 and xlig <= 15 then
+
+			meta:set_string("command", fields.text)
+			meta:set_string("infotext", "Spawner Active (" .. mob .. ")")
+
+		else
+			minetest.chat_send_player(name, "Mob Spawner settings failed!")
+		end
+	end,
+})
+
+-- spawner abm
+minetest.register_abm({
+	nodenames = {"mobs:spawner"},
+	interval = 10,
+	chance = 4,
+	catch_up = false,
+
+	action = function(pos, node, active_object_count, active_object_count_wider)
+
+		-- check objects inside 9x9 area around spawner
+		local objs = minetest.get_objects_inside_radius(pos, 9)
+
+		-- get meta and command
+		local meta = minetest.get_meta(pos)
+		local comm = meta:get_string("command"):split(" ")
+
+		-- get settings from command
+		local mob = comm[1]
+		local mlig = tonumber(comm[2])
+		local xlig = tonumber(comm[3])
+		local num = tonumber(comm[4])
+
+		-- if amount is 0 then do nothing
+		if num == 0 then
+			return
+		end
+
+		local count = 0
+		local ent = nil
+
+		-- count objects of same type in area
+		for k, obj in pairs(objs) do
+
+			ent = obj:get_luaentity()
+
+			if ent and ent.name == mob then
+				count = count + 1
+			end
+		end
+
+		-- is there too many of same type?
+		if count >= num then
+			return
+		end
+
+		-- find air blocks within 5 nodes of spawner
+		local air = minetest.find_nodes_in_area(
+			{x = pos.x - 5, y = pos.y, z = pos.z - 5},
+			{x = pos.x + 5, y = pos.y, z = pos.z + 5},
+			{"air"})
+
+		-- spawn in random air block
+		if air and #air > 0 then
+
+			local pos2 = air[math.random(#air)]
+			local lig = minetest.get_node_light(pos2)
+
+			-- only if light levels are within range
+			if lig and lig >= mlig and lig <= xlig then
+				minetest.add_entity(pos2, mob)
+			end
+		end
+
+	end
+})