Throw Kohana exception if json function returns nothing

gistfile1.php

<?php
/**
 * Throw Kohana exception if json function returns nothing
 *
 * @example
 *    $en = json_encode("\xB1\x31");
 *
 *    check_json_error($en);
 *
 *    $de = json_decode("{'Organization': 'Kohana'}");
 *
 *    check_json_error($de);
 *
 * @param mixed $json_result
 */

function check_json_error($json_result)
{
	if($json_result == NULL OR $json_result == 'null')
	{
		$error = '';
		
		switch(json_last_error())
		{
			case JSON_ERROR_DEPTH:
				$error = 'Maximum stack depth exceeded';
				break;
			case JSON_ERROR_CTRL_CHAR:
				$error = 'Unexpected control character found';
				break;
			case JSON_ERROR_STATE_MISMATCH:
				$error = 'Invalid or malformed JSON';
				break;
			case JSON_ERROR_SYNTAX:
				$error = 'Syntax error';
				break;
			case JSON_ERROR_UTF8:
				$error = 'Malformed UTF-8 characters, possibly incorrectly encoded';
		}
		
		if ($error)
		{
			throw new Kohana_Exception('JSON error: :error', array(':error' => $error));
		}
	}
}