Youtube ID 解析新的 URL 格式

我不得不为几周前编写的PHP类处理这个问题，最终得到了一个匹配任何类型字符串的正则表达式：有或没有URL方案，有或没有子域，youtube.com URL字符串，youtu.be URL字符串并处理各种参数排序。您可以在GitHub上查看它，或者只需复制并粘贴下面的代码块：

/**
 *  Check if input string is a valid YouTube URL
 *  and try to extract the YouTube Video ID from it.
 *  @author  Stephan Schmitz <eyecatchup@gmail.com>
 *  @param   $url   string   The string that shall be checked.
 *  @return  mixed           Returns YouTube Video ID, or (boolean) false.
 */
function parse_yturl($url)
{
    $pattern = '#^(?:https?://|//)?(?:www\.|m\.)?(?:youtu\.be/|youtube\.com/(?:embed/|v/|watch\?v=|watch\?.+&v=))([\w-]{11})(?![\w-])#';
    preg_match($pattern, $url, $matches);
    return (isset($matches[1])) ? $matches[1] : false;
}

测试用例：https://3v4l.org/GEDT0
JavaScript 版本：https://stackoverflow.com/a/10315969/624466

为了解释正则表达式，这里有一个拆分版本：

/**
 *  Check if input string is a valid YouTube URL
 *  and try to extract the YouTube Video ID from it.
 *  @author  Stephan Schmitz <eyecatchup@gmail.com>
 *  @param   $url   string   The string that shall be checked.
 *  @return  mixed           Returns YouTube Video ID, or (boolean) false.
 */
function parse_yturl($url)
{
    $pattern = '#^(?:https?://|//)?' # Optional URL scheme. Either http, or https, or protocol-relative.
             . '(?:www\.|m\.)?'      #  Optional www or m subdomain.
             . '(?:'                 #  Group host alternatives:
             .   'youtu\.be/'        #    Either youtu.be,
             .   '|youtube\.com/'    #    or youtube.com
             .     '(?:'             #    Group path alternatives:
             .       'embed/'        #      Either /embed/,
             .       '|v/'           #      or /v/,
             .       '|watch\?v='    #      or /watch?v=,
             .       '|watch\?.+&v=' #      or /watch?other_param&v=
             .     ')'               #    End path alternatives.
             . ')'                   #  End host alternatives.
             . '([\w-]{11})'         # 11 characters (Length of Youtube video ids).
             . '(?![\w-])#';         # Rejects if overlong id.
    preg_match($pattern, $url, $matches);
    return (isset($matches[1])) ? $matches[1] : false;
}

我发现这个代码这个链接：

<?php 
/** 
 *  parse_youtube_url() PHP function 
 *  Author: takien 
 *  URL: http://takien.com 
 *  
 *  @param  string  $url    URL to be parsed, eg:  
 *                            http://youtu.be/zc0s358b3Ys,  
 *                            http://www.youtube.com/embed/zc0s358b3Ys
 *                            http://www.youtube.com/watch?v=zc0s358b3Ys 
 *  @param  string  $return what to return 
 *                            - embed, return embed code 
 *                            - thumb, return URL to thumbnail image
 *                            - hqthumb, return URL to high quality thumbnail image.
 *  @param  string     $width  width of embeded video, default 560
 *  @param  string  $height height of embeded video, default 349
 *  @param  string  $rel    whether embeded video to show related video after play or not.

 */  

 function parse_youtube_url($url,$return='embed',$width='',$height='',$rel=0){ 
    $urls = parse_url($url); 

    //expect url is http://youtu.be/abcd, where abcd is video iD
    if($urls['host'] == 'youtu.be'){  
        $id = ltrim($urls['path'],'/'); 
    } 
    //expect  url is http://www.youtube.com/embed/abcd 
    else if(strpos($urls['path'],'embed') == 1){  
        $id = end(explode('/',$urls['path'])); 
    } 
     //expect url is abcd only 
    else if(strpos($url,'/')===false){ 
        $id = $url; 
    } 
    //expect url is http://www.youtube.com/watch?v=abcd 
    else{ 
        parse_str($urls['query']); 
        $id = $v; 
    } 
    //return embed iframe 
    if($return == 'embed'){ 
        return '<iframe width="'.($width?$width:560).'" height="'.($height?$height:349).'" src="http://www.youtube.com/embed/'.$id.'?rel='.$rel.'" frameborder="0" allowfullscreen>'; 
    } 
    //return normal thumb 
    else if($return == 'thumb'){ 
        return 'http://i1.ytimg.com/vi/'.$id.'/default.jpg'; 
    } 
    //return hqthumb 
    else if($return == 'hqthumb'){ 
        return 'http://i1.ytimg.com/vi/'.$id.'/hqdefault.jpg'; 
    } 
    // else return id 
    else{ 
        return $id; 
    } 
} 
?>

我也在处理这个问题，所以如果你找到一个更好的解决方案，请让我知道。它不能完全满足您开箱即用的图像需求，但可以轻松适应。