从URL w/PHP获取YouTube视频ID

Question

我正在尝试创建一个函数,该函数从Wordpress自定义字段调用值("_videourl"表示YouTube视频网址),然后使用PHP修剪将其缩小为YouTube视频ID.我发现了一个javascript函数,可以将URL减少到ID,但我不知道我怎么能将它转换成php(下面的函数):

     function youtubeIDextract(url) 
     { 
     var youtube_id; 
     youtube_id = url.replace(/^[^v]+v.(.{11}).*/,"$1"); 
     return youtube_id; 
     }

这个PHP函数将在循环中使用,所以我想我必须使用变量,但我真的只是一个菜鸟,所以我不知道该怎么做.任何人都可以通过分享他们的编码专业知识来帮助我创建PHP函数吗？

编辑:解决

经过一些实验,我找到了解决方案.我想返回并发布它,以便其他有需要的人可以从某个地方开始.

function getYoutubeId($ytURL) 
    {
        $urlData = parse_url($ytURL);
        //echo '<br>'.$urlData["host"].'<br>';
        if($urlData["host"] == 'www.youtube.com') // Check for valid youtube url
        {
            $ytvIDlen = 11; // This is the length of YouTube's video IDs

            // The ID string starts after "v=", which is usually right after 
            // "youtube.com/watch?" in the URL
            $idStarts = strpos($ytURL, "?v=");

            // In case the "v=" is NOT right after the "?" (not likely, but I like to keep my 
            // bases covered), it will be after an "&":
            if($idStarts === FALSE)
                $idStarts = strpos($ytURL, "&v=");
            // If still FALSE, URL doesn't have a vid ID
            if($idStarts === FALSE)
                die("YouTube video ID not found. Please double-check your URL.");

            // Offset the start location to match the beginning of the ID string
            $idStarts +=3;

            // Get the ID string and return it
            $ytvID = substr($ytURL, $idStarts, $ytvIDlen);

            return $ytvID;
        }
        else
        {
            //echo 'This is not a valid youtube video url. Please, give a valid url...';
            return 0;
        }

    } 

Answer 1

我不得不处理这个几周前写的PHP类,结果是一个匹配任何类型的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字符串和处理所有类型的参数排序.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) 
{
    $pattern = '#^(?:https?://)?(?:www\.)?(?:youtu\.be/|youtube\.com(?:/embed/|/v/|/watch\?v=|/watch\?.+&v=))([\w-]{11})(?:.+)?$#x';
    preg_match($pattern, $url, $matches);
    return (isset($matches[1])) ? $matches[1] : false;
}

为了解释正则表达式,这是一个溢出的版本:

/**
 *  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.
    $pattern .= '(?:www\.)?';         #  Optional www subdomain.
    $pattern .= '(?:';                #  Group host alternatives:
    $pattern .=   'youtu\.be/';       #    Either youtu.be,
    $pattern .=   '|youtube\.com';    #    or youtube.com
    $pattern .=   '(?:';              #    Group path alternatives:
    $pattern .=     '/embed/';        #      Either /embed/,
    $pattern .=     '|/v/';           #      or /v/,
    $pattern .=     '|/watch\?v=';    #      or /watch?v=,    
    $pattern .=     '|/watch\?.+&v='; #      or /watch?other_param&v=
    $pattern .=   ')';                #    End path alternatives.
    $pattern .= ')';                  #  End host alternatives.
    $pattern .= '([\w-]{11})';        # 11 characters (Length of Youtube video ids).
    $pattern .= '(?:.+)?$#x';         # Optional other ending URL parameters.
    preg_match($pattern, $url, $matches);
    return (isset($matches[1])) ? $matches[1] : false;
}