I'm really having some difficult wrapping my head around regex and preg_replace. What I want to do is have a function that scans an entire page for any <a href> tags pointing to Youtube and then convert them into an embedded youtube video.

Here's a code to show kinda of what I mean:

<?php
$youtubelink = "http://www.youtube.com/watch?v=Ysl6NCoshk8";
$vid_section = substr( $youtubelink, strpos($youtubelink, '?') + 1, 1 );

$vid_id = substr( $youtubelink, strpos($youtubelink, '=') + 1 );

$embed_code = '<object width="560" height="340"><param name="movie" value="http://www.youtube.com/'.$vid_section.'/'.$vid_id.'&hl=en&fs=1&"></param><param name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="http://www.youtube.com/'.$vid_section.'/'.$vid_id.'&hl=en&fs=1&" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="560" height="340"></embed></object>';

echo $embed_code;
?>

First of all I don't want to be providing the link, I want the function to search for it itself. So here's my stab at regex and preg_replace:

echo preg_replace('#(?:<\>]+href=\")?(?:http://)?((?:[a-zA-Z]{1,4}\.)?youtube.com/(?:watch)?\?v=(.{11}?))[^"]*(?:\"[^\<\>]*>)?([^\<\>]*)(?:)?#', '<object width="425" height="350"><param name="movie" value="http://www.youtube.com/v/'.$matches[2].'"></param><param name="wmode" value="transparent"></param><embed src="http://www.youtube.com/v/'.$matches[2].'" type="application/x-shockwave-flash" wmode="transparent" width="425" height="350"></embed></object>', $ENTIREPAGE?);

Any idea where I'm going wrong?

To give a little more insight (if your bored enough to care), I have a tumblr blog that posts my twitter RSS feed updates. I sometimes post youtube links and would like them to show up as embedded videos for users to watch on the tumblr page.

Cheers.

If you are talking about grabbing the youtube links from a page the following scripts will do that and display each video id in a list.

<?php
$input=file_get_contents('http://www.youtube.com/');
preg_match_all('#(http://www.youtube.com)?/(v/([-|~_0-9A-Za-z]+)|watch\?v\=([-|~_0-9A-Za-z]+)&?.*?)#i',$input,$output);
foreach ($output[3] AS $video_id) {
    echo $video_id.'<br>';
    }
foreach ($output[4] AS $video_id) {
    echo $video_id.'<br>';
    }
?>

Awesome. Worked like a charm. Here's the final code I got:

<?php
$input=file_get_contents('http://warrendunlop.tumblr.com');
preg_match_all('#(http://www.youtube.com)?/(v/([-|~_0-9A-Za-z]+)|watch\?v\=([-|~_0-9A-Za-z]+)&?.*?)#i',$input,$output);
foreach ($output[4] AS $video_id) {
$embed_code = '<object width="560" height="340"><param name="movie" value="http://www.youtube.com/v/'.$video_id.'&hl=en&fs=1&"></param><param name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="http://www.youtube.com/v/'.$video_id.'&hl=en&fs=1&" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="560" height="340"></embed></object>';
echo $embed_code.'<br>';
    }
?>

I am having a couple new problems. It seems to embedding doubles for each link on the blog page. Any way to check for a twin link? (you can see what I mean on my test page: www.warrendunlop.com/youtube_embed.php

I also am not sure how I would scan the current document instead of an external one.

To only do each video id once the following is what the code would look like.

<?php
$input=file_get_contents('http://warrendunlop.tumblr.com');
preg_match_all('#(http://www.youtube.com)?/(v/([-|~_0-9A-Za-z]+)|watch\?v\=([-|~_0-9A-Za-z]+)&?.*?)#i',$input,$output);
foreach ($output[4] AS $video_id) {
    if (!isset($video[$video_id])) {
    $video[$video_id]=true;
$embed_code = '<object width="560" height="340"><param name="movie" value="http://www.youtube.com/v/'.$video_id.'&hl=en&fs=1&"></param><param name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="http://www.youtube.com/v/'.$video_id.'&hl=en&fs=1&" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="560" height="340"></embed></object>';
echo $embed_code.'<br>';
        }
    }
?>

You are a legend sir.

Much thanks.