redef fun []=(key, value)
	do
		var nsobject: NSString

		if value == null then
			nsobject = new NSString.nil
		else
			var serialized_string = new StringWriter
			var serializer = new JsonSerializer(serialized_string)
			serializer.serialize(value)

			# TODO report errors
			nsobject = serialized_string.to_s.to_nsstring
		end

		user_defaults.set_object(nsobject, key.to_nsstring)
	end

	redef fun []=(key, value)
	do
		# Get DB
		var db = self.db
		if db == null then return

		# Serialize
		var stream = new StringWriter
		var serializer = new JsonSerializer(stream)
		serializer.serialize value
		var serialized = stream.to_s

		# Save in DB
		db.execute "BEGIN TRANSACTION"
		db.insert "OR REPLACE INTO {db_table} VALUES({key.to_sql_string}, {serialized.to_sql_string})"
		db.execute "COMMIT"
	end

	redef fun []=(key, value) do shared_preferences[key] = value