jidaikobo-shibata/a11yc

<?php
/**
 * * A11yc\Validate\Check\LinkCheck
 *
 * @package    part of A11yc
 * @author     Jidaikobo Inc.
 * @license    The MIT License (MIT)
 * @copyright  Jidaikobo Inc.
 * @link       http://www.jidaikobo.com
 */
namespace A11yc\Validate\Check;

use A11yc\Element;
use A11yc\Validate;

class LinkCheck extends Validate
{
    /**
     * check
     *
     * @param String $url
     * @return Void
     */
    public static function check($url)
    {
        Validate\Set::log($url, 'link_check', self::$unspec, 5);
        if ( ! static::$do_link_check) return;
        Validate\Set::log($url, 'link_check', self::$unspec, 1);

        $str = Element\Get::ignoredHtml($url);
        $ms = Element\Get::elementsByRe($str, 'ignores', 'tags');
        if ( ! $ms[0]) return;

        // candidates
        $checks = array(
            'a',
            'img',
            'form',
            'meta',
        );

        // fragments
        preg_match_all("/ (?:id|name) *?= *?[\"']([^\"']+?)[\"']/i", $str, $fragments);

        foreach ($ms[0] as $k => $tag)
        {
            $ele = $ms[1][$k];

            if ( ! in_array($ele, $checks)) continue;
            $attrs = Element\Get::attributes($tag);

            $target_url = self::getTargetUrl($attrs);
            if ( ! $target_url) continue;

            // fragments
            if ($target_url[0] == '#')
            {
                if ( ! in_array(substr($target_url, 1), $fragments[1]))
                {
                    Validate\Set::error($url, 'link_check', $k, $tag, 'Fragment Not Found: '.$target_url);
                }
                continue;
            }

            // correct url
            if (Element::isIgnorable($tag)) continue;

            $target_url = Util::enuniqueUri($target_url);

            // remove strange ampersand. seems depend on environment ?-(
            $target_url = str_replace('&#038;', '&', $target_url);

            // links
            if ( ! Crawl::isPageExist($target_url))
            {
                Validate\Set::error($url, 'link_check', $k, $tag, 'Not Found: '.$target_url);
                continue;
            }

            // 40x
            $headers = @get_headers($target_url);
            if ($headers !== false && strpos($headers[0], ' 40') !== false)
            {
                Validate\Set::error($url, 'link_check', $k, $tag, 'header 40x: '.$target_url);
            }
        }

        if (isset(static::$error_ids[$url]))
        {
            static::addErrorToHtml($url, 'link_check', static::$error_ids[$url], 'ignores_comment_out');
        }
    }

    /**
     * get target url
     *
     * @param Array $attrs
     * @return String
     */
    protected static function getTargetUrl($attrs)
    {
        if (isset($attrs['href']))
        {
            return $attrs['href'];
        }
        elseif (isset($attrs['src']))
        {
            return $attrs['src'];
        }
        elseif (isset($attrs['action']))
        {
            return $attrs['action'];
        }
        elseif (isset($attrs['property']))
        {
            if ($attrs['property'] == 'og:url' || $attrs['property'] == 'og:image')
            {
                return $attrs['content'];
            }
        }
        return '';
    }
}