<?php

/**

 * WordPress Error API.

 *

 * Contains the WP_Error class and the is_wp_error() function.

 *

 * @package WordPress

 */

/**

 * WordPress Error class.

 *

 * Container for checking for WordPress errors and error messages. Return

 * WP_Error and use {@link is_wp_error()} to check if this class is returned.

 * Many core WordPress functions pass this class in the event of an error and

 * if not handled properly will result in code errors.

 *

 * @package WordPress

 * @since 2.1.0

 */

class WP_Error {

	/**

	 * Stores the list of errors.

	 *

	 * @since 2.1.0

	 * @var array

	 * @access private

	 */

	var $errors = array();

	/**

	 * Stores the list of data for error codes.

	 *

	 * @since 2.1.0

	 * @var array

	 * @access private

	 */

	var $error_data = array();

	/**

	 * Constructor - Sets up error message.

	 *

	 * If code parameter is empty then nothing will be done. It is possible to

	 * add multiple messages to the same code, but with other methods in the

	 * class.

	 *

	 * All parameters are optional, but if the code parameter is set, then the

	 * data parameter is optional.

	 *

	 * @since 2.1.0

	 *

	 * @param string|int $code Error code

	 * @param string $message Error message

	 * @param mixed $data Optional. Error data.

	 * @return WP_Error

	 */

	function __construct($code = '', $message = '', $data = '') {

		if ( empty($code) )

			return;

		$this->errors[$code][] = $message;

		if ( ! empty($data) )

			$this->error_data[$code] = $data;

	}

	/**

	 * Retrieve all error codes.

	 *

	 * @since 2.1.0

	 * @access public

	 *

	 * @return array List of error codes, if available.

	 */

	function get_error_codes() {

		if ( empty($this->errors) )

			return array();

		return array_keys($this->errors);

	}

	/**

	 * Retrieve first error code available.

	 *

	 * @since 2.1.0

	 * @access public

	 *

	 * @return string|int Empty string, if no error codes.

	 */

	function get_error_code() {

		$codes = $this->get_error_codes();

		if ( empty($codes) )

			return '';

		return $codes[0];

	}

	/**

	 * Retrieve all error messages or error messages matching code.

	 *

	 * @since 2.1.0

	 *

	 * @param string|int $code Optional. Retrieve messages matching code, if exists.

	 * @return array Error strings on success, or empty array on failure (if using code parameter).

	 */

	function get_error_messages($code = '') {

		// Return all messages if no code specified.

		if ( empty($code) ) {

			$all_messages = array();

			foreach ( (array) $this->errors as $code => $messages )

				$all_messages = array_merge($all_messages, $messages);

			return $all_messages;

		}

		if ( isset($this->errors[$code]) )

			return $this->errors[$code];

		else

			return array();

	}

	/**

	 * Get single error message.

	 *

	 * This will get the first message available for the code. If no code is

	 * given then the first code available will be used.

	 *

	 * @since 2.1.0

	 *

	 * @param string|int $code Optional. Error code to retrieve message.

	 * @return string

	 */

	function get_error_message($code = '') {

		if ( empty($code) )

			$code = $this->get_error_code();

		$messages = $this->get_error_messages($code);

		if ( empty($messages) )

			return '';

		return $messages[0];

	}

	/**

	 * Retrieve error data for error code.

	 *

	 * @since 2.1.0

	 *

	 * @param string|int $code Optional. Error code.

	 * @return mixed Null, if no errors.

	 */

	function get_error_data($code = '') {

		if ( empty($code) )

			$code = $this->get_error_code();

		if ( isset($this->error_data[$code]) )

			return $this->error_data[$code];

		return null;

	}

	/**

	 * Append more error messages to list of error messages.

	 *

	 * @since 2.1.0

	 * @access public

	 *

	 * @param string|int $code Error code.

	 * @param string $message Error message.

	 * @param mixed $data Optional. Error data.

	 */

	function add($code, $message, $data = '') {

		$this->errors[$code][] = $message;

		if ( ! empty($data) )

			$this->error_data[$code] = $data;

	}

	/**

	 * Add data for error code.

	 *

	 * The error code can only contain one error data.

	 *

	 * @since 2.1.0

	 *

	 * @param mixed $data Error data.

	 * @param string|int $code Error code.

	 */

	function add_data($data, $code = '') {

		if ( empty($code) )

			$code = $this->get_error_code();

		$this->error_data[$code] = $data;

	}

}

/**

 * Check whether variable is a WordPress Error.

 *

 * Returns true if $thing is an object of the WP_Error class.

 *

 * @since 2.1.0

 *

 * @param mixed $thing Check if unknown variable is a WP_Error object.

 * @return bool True, if WP_Error. False, if not WP_Error.

 */

function is_wp_error($thing) {

	if ( is_object($thing) && is_a($thing, 'WP_Error') )

		return true;

	return false;

}