Swap all youtube urls to embed via preg_replace()

问题:

Hello I'm trying to convert youtube links into embed code.

this is what I have:

<?php

$text = $post->text;

     $search = '#<a(.*?)(?:href="https?://)?(?:www\.)?(?:youtu\.be/|youtube\.com(?:/embed/|/v/|/watch?.*?v=))([\w\-]{10,12}).*$#x';
     $replace = '<center><iframe width="560" height="315" src="http://www.youtube.com/embed/$2" frameborder="0" allowfullscreen></iframe></center>';
     $text = preg_replace($search, $replace, $text);


echo $text;
?>

It works for one link. However if I add two, it will only swap the last occurrence. What do I have to change?

回答1:

You're not handling the end of the string properly. Remove the $, and replace it with the closing tag </a>. this will fix it.

 $search = '#<a(.*?)(?:href="https?://)?(?:www\.)?(?:youtu\.be/|youtube\.com(?:/embed/|/v/|/watch?.*?v=))([\w\-]{10,12}).*<\/a>#x';
 $replace = '<center><iframe width="560" height="315" src="http://www.youtube.com/embed/$2" frameborder="0" allowfullscreen></iframe></center>';
 $text = preg_replace($search, $replace, $text);

回答2:

Try this : preg_replace($search, $replace, $text, -1);

I know it's the default but who knows...

EDIT Try that if not working ;

do{
    $text = preg_replace($search, $replace, $text, -1, $Count);
}
while($Count);

回答3:

Here are a regular expresion more efficient: http://pregcopy.com/exp/26, tralate this to PHP: (add "s" modifier)

<?php

$text = $post->text;

     $search = '#<a (?:.*?)href=["\\\']http[s]?:\/\/(?:[^\.]+\.)*youtube\.com\/(?:v\/|watch\?(?:.*?\&)?v=|embed\/)([\w\-\_]+)["\\\']#ixs';
     $replace = '<center><iframe width="560" height="315" src="http://www.youtube.com/embed/$1" frameborder="0" allowfullscreen></iframe></center>';

     $text = preg_replace($search, $replace, $text);


echo $text;
?>

Test it

回答4:

There are two types of youtube link for one video:

Example:

$link1 = 'https://www.youtube.com/watch?v=NVcpJZJ60Ao';
$link2 = 'https://www.youtu.be/NVcpJZJ60Ao';

This function handles both:

function getYoutubeEmbedUrl($url)
{
     $shortUrlRegex = '/youtu.be\/([a-zA-Z0-9_-]+)\??/i';
$longUrlRegex = '/youtube.com\/((?:embed)|(?:watch))((?:\?v\=)|(?:\/))([a-zA-Z0-9_-]+)/i';

    if (preg_match($longUrlRegex, $url, $matches)) {
        $youtube_id = $matches[count($matches) - 1];
    }

    if (preg_match($shortUrlRegex, $url, $matches)) {
        $youtube_id = $matches[count($matches) - 1];
    }
    return 'https://www.youtube.com/embed/' . $youtube_id ;
}

The output of $link1 or $link2 would be the same :

 $output1 = getYoutubeEmbedUrl($link1);
 $output2 = getYoutubeEmbedUrl($link2);
 // output for both:  https://www.youtube.com/embed/NVcpJZJ60Ao

Now you can use the output in iframe!