Match all youtube links in a string of text

Question

I'm looking to pull all the youtube links from a string of text and was wondering how does this look?

if (preg_match_all('/(https?:\/\/)?(www\.)?(youtube\.com)\/watch\?v=([a-zA-Z0-9_-]+)[^\s]*/im', $this->content, $matches)) {

}

Obviously this doesn't take into account the youtu.be links as they are formatted differently.

Answer 1

1. [^\s] is effectively just \S

2. For checking against youtu.be links, you can have:

   youtu(\.be|be\.com)
   

3. If you do not want to store every matched group, use (?:...)
4. [A-Za-z0-9_] can be simplified to \w.
5. Use a different delimiter than / so that you won't have to escape it in pattern.

Therefore:

preg_match_all(
    '@(https?://)?(?:www\.)?(youtu(?:\.be/([-\w]+)|be\.com/watch\?v=([-\w]+)))\S*@im',
    $this->content,
    $matches
)

Answer 2

A YouTube /watch URL can have query string parameters besides the video ID v. For example, hd=1 requests a high-definition stream. There can be a t=4m33s parameter to make the video player start at the indicated point in the video. You can even use wadsworth=1 to apply the Wadsworth Constant.

Technically, query string parameters can occur in any order, and the resulting URLs are generally considered semantically identical. Therefore, you should handle the possibility that some other query parameters might come between /watch? and v=.