使用php验证youtube网址的问题

Question

I'm trying to validate a youtube url taken from a form field. The way I have it setup isn't catching any error no matter what I put in. I use getVideoId() to extract the video id from the url which works.

    if ($_POST['video_url'] != null && $_POST['video_url'] != 'Youtube URL') {
        $vid_url = $_POST['video_url'];
        $video_id = getVideoId($vid_url);
        $headers = get_headers('http://gdata.youtube.com/feeds/api/videos/' . $video_id);
          if (strpos($headers[0], '200')) {
            $video_url = $vid_url;
          } else {
            $output .= 'This is not an existing youtube video<br/>';
          }
    }

The $output is set to null and I check against that before processing the form which works for how I validate other fields so it's just this method that is failing.

Answer 1

If there is no valid video id, then $video_id is blank. If you try:

$headers = get_headers('http://gdata.youtube.com/feeds/api/videos/');
echo $headers[0];

you'll see that it returns a 200.

$headers = get_headers('http://gdata.youtube.com/feeds/api/videos/SOMETHINGINVALID');
echo $headers[0];

returns a 4xx of some description.

You'll need to trap both cases:

if ($_POST['video_url'] != null && $_POST['video_url'] != 'Youtube URL') {
    $vid_url = $_POST['video_url'];
    $video_id = getVideoId($vid_url);
    if ($video_id) {
        $headers = get_headers('http://gdata.youtube.com/feeds/api/videos/' . $video_id);
        if (strpos($headers[0], '200')) {
            $video_url = $vid_url;
          } else {
              $output .= 'This is not an existing youtube video<br/>';
          }
    } else {
          $output .= 'This is not an existing youtube video<br/>';
    }
}