Elep

<?php

/**
 * Base class for link checking algorithms.
 *
 * All link checkering algorithms should extend this class.
 *
 * @package Broken Link Checker
 * @access public
 */
class blcChecker extends blcModule {

/**
	 * Priority determines the order in which the plugin will try all registered checkers
	 * when looking for one that can check a particular URL. Registered checkers will be
	 * tried in order, from highest to lowest priority, and the first one that returns
	 * true when its can_check() method is called will be used.
	 *
	 * Checker implementations should set their priority depending on how specific they are
	 * in choosing the URLs that they check.
	 *
	 * -10 .. 10  : checks all URLs that have a certain protocol, e.g. all HTTP URLs.
	 * 11  .. 100 : checks only URLs from a restricted number of domains, e.g. video site URLs.
	 * 100+       : checks only certain URLs from a certain domain, e.g. YouTube video links.
	 *
	 */
	var $priority = -100;

/**
	 * Check if this checker knows how to check a particular URL.
	 *
	 * @param string $url
	 * @param array|bool $parsed_url The result of parsing $url with parse_url(). See PHP docs for details.
	 * @return bool
	 */
	function can_check( $url, $parsed_url ) {
		return false;
	}

/**
	 * Check an URL.
	 *
	 * This method returns an associative array containing results of
	 * the check. The following array keys are recognized by the plugin and
	 * their values will be stored in the link's DB record :
	 *    'broken' (bool) - True if the URL points to a missing/broken page. Required.
	 *    'http_code' (int) - HTTP code returned when requesting the URL. Defaults to 0.
	 *    'redirect_count' (int) - The number of redirects. Defaults to 0.
	 *    'final_url' (string) - The redirected-to URL. Assumed to be equal to the checked URL by default.
	 *    'request_duration' (float) - How long it took for the server to respond. Defaults to 0 seconds.
	 *    'timeout' (bool) - True if checking the URL resulted in a timeout. Defaults to false.
	 *    'may_recheck' (bool) - Allow the plugin to re-check the URL after 'recheck_threshold' seconds (see broken-link-checker.php).
	 *    'log' (string) - Free-form log of the performed check. It will be displayed in the "Details" section of the checked link.
	 *    'result_hash' (string) - A free-form hash or code uniquely identifying the detected link status. See sub-classes for examples. Max 200 characters.
	 *
	 * @see blcLink:check()
	 *
	 * @param string $url
	 * @return array
	 */
	function check( $url ) {
		trigger_error( 'Function blcChecker::check() must be over-ridden in a subclass', E_USER_ERROR );
	}
}

class blcCheckerHelper {

/**
	 * Get a reference to a specific checker.
	 *
	 * @uses blcModuleManager::get_module()
	 *
	 * @param string $checker_id
	 * @return blcChecker
	 */
	static function get_checker( $checker_id ) {
		$manager = blcModuleManager::getInstance();
		return $manager->get_module( $checker_id, true, 'checker' );
	}

/**
	 * Get a checker object that can check the specified URL.
	 *
	 * @param string $url
	 * @return blcChecker|null
	 */
	static function get_checker_for( $url ) {
		$parsed = @parse_url( $url );

$manager         = blcModuleManager::getInstance();
		$active_checkers = $manager->get_active_by_category( 'checker' );
		foreach ( $active_checkers as $module_id => $module_data ) {
			//Try the URL pattern in the header first. If it doesn't match,
			//we can avoid loading the module altogether.
			if ( ! empty( $module_data['ModuleCheckerUrlPattern'] ) ) {
				if ( ! preg_match( $module_data['ModuleCheckerUrlPattern'], $url ) ) {
					continue;
				}
			}

$checker = $manager->get_module( $module_id );

if ( ! $checker ) {
				continue;
			}

//The can_check() method can perform more sophisticated filtering,
			//or just return true if the checker thinks matching the URL regex
			//is sufficient.
			if ( $checker->can_check( $url, $parsed ) ) {
				return $checker;
			}
		}

$checker = null;
		return $checker;
	}
}