Add method for cleaning/replacing items

TODO.txt

@@ -1,4 +1,3 @@
 
 TODO:
 - allow nodes to be cleaned to be replaced by another node
-- methods for cleaning/replacing items

changelog.txt

@@ -3,6 +3,7 @@
 - changed license to MIT
 - "clean_entities" & "clean_nodes" files now use json format
 - nodes can be replaced with other nodes
+- items can be replaced with other items (<world_path>/clean_items.json file)
 
 
 0.4

init.lua

@@ -34,6 +34,7 @@ end
 local scripts = {
 	"entities",
 	"nodes",
+	"items",
 }
 
 for _, script in ipairs(scripts) do

items.lua

@@ -0,0 +1,55 @@
+
+local misc = dofile(cleaner.modpath .. "/misc_functions.lua")
+
+-- populate nodes list from file in world path
+local i_list = {replace={}}
+local i_path = core.get_worldpath() .. "/clean_items.json"
+local i_file = io.open(i_path, "r")
+
+if i_file then
+	local data_in = core.parse_json(i_file:read("*a"))
+	i_file:close()
+	if data_in then
+		i_list = data_in
+	end
+end
+
+-- update json file with any changes
+i_file = io.open(i_path, "w")
+if i_file then
+	local data_out = core.write_json(i_list, true)
+
+	data_out = data_out:gsub("\"replace\" : null", "\"replace\" : {}")
+
+	i_file:write(data_out)
+	i_file:close()
+end
+
+-- register actions for after server startup
+core.after(0, function()
+	for i_old, i_new in pairs(i_list.replace) do
+		cleaner.log("action", "replacing item \"" .. i_old .. "\" with \"" .. i_new .. "\"")
+
+		if not core.registered_items[i_old] then
+			cleaner.log("info", "\"" .. i_old .. "\" not registered, not unregistering")
+		else
+			cleaner.log("warning", "overriding registered item \"" .. i_old .. "\"")
+
+			core.unregister_item(i_old)
+			if core.registered_items[i_old] then
+				cleaner.log("error", "could not unregister \"" .. i_old .. "\"")
+			end
+		end
+
+		if not core.registered_items[i_new] then
+			cleaner.log("warning", "adding alias for unregistered item \"" .. i_new .. "\"")
+		end
+
+		core.register_alias(i_old, i_new)
+		if core.registered_aliases[i_old] == i_new then
+			cleaner.log("info", "registered alias \"" .. i_old .. "\" for \"" .. i_new .. "\"")
+		else
+			cleaner.log("error", "could not register alias \"" .. i_old .. "\" for \"" .. i_new .. "\"")
+		end
+	end
+end)