Add API for reading/writing json configs in world path

api.lua

@@ -0,0 +1,89 @@
+
+-- store formatted world path
+local world_path = core.get_worldpath():gsub("\\", "/")
+
+--- Retrieves directory path where file is located.
+--
+--  @local
+--  @get_dir
+--  @tparam string fpath Full path to file.
+--  @treturn string Full path to directory.
+local function get_dir(fpath)
+	-- format to make working with easier
+	fpath = fpath:gsub("\\", "/")
+	local idx = fpath:find("/[^/]*$")
+
+	-- use world directory by default
+	if not idx or idx == 0 then
+		return world_path
+	end
+
+	return fpath:sub(1, idx-1)
+end
+
+
+--- Reads config file from world directory.
+--
+--  @function wconfig.read
+--  @tparam string fname Base filename with optional directory structure (e.g. "my_mod/my_config")
+--  @treturn table Table with contents read from json file or `nil`.
+function wconfig.read(fname)
+	local fpath = world_path .. "/" .. fname .. ".json"
+
+	-- check if file exists
+	local fopen = io.open(fpath, "r")
+	if not fopen then
+		wconfig.log("error", "file not found: " .. fpath)
+		return
+	end
+
+	local table_data = core.parse_json(fopen:read("*a"))
+	io.close(fopen)
+
+	if not table_data then
+		wconfig.log("error", "cannot read json data from file: " .. fpath)
+		return
+	end
+
+	return table_data
+end
+
+
+--- Writes to config file in world directory.
+--
+--  @function wconfig.write
+--  @tparam string fname Base filename with optional directory structure (e.g. "my_mod/my_config").
+--  @tparam table data Table data to be written to config file.
+--  @tparam bool styled Outputs in a human-readable format if this is set (default: `true`).
+--  @treturn bool `true` if succeeded, `false` if not.
+function wconfig.write(fname, data, styled)
+	styled = styled ~= false
+
+	local json_data = core.write_json(data, styled)
+	if not json_data then
+		wconfig.log("error", "cannot convert data to json format")
+		return false
+	end
+
+	local fpath = world_path .. "/" .. fname .. ".json"
+
+	-- create directory tree if necessary
+	local dirname = get_dir(fpath)
+	if dirname ~= world_path then
+		if not core.mkdir(dirname) then
+			wconfig.log("error", "cannot create directory: " .. dirname)
+			return false
+		end
+	end
+
+	return core.safe_file_write(fpath, json_data)
+end
+
+
+-- aliases
+if not core.read_world_config then
+	core.read_world_config = wconfig.read
+end
+if not core.write_world_config then
+	core.write_world_config = wconfig.write
+end

init.lua

@@ -16,3 +16,6 @@ function wconfig.log(lvl, msg)
 		core.log(lvl, msg)
 	end
 end
+
+
+dofile(wconfig.modpath .. "/api.lua")