Grab URL within a string which contains HTML code - php

Question

I have a string, for example:
$html = '<p>helloworld</p><p>helloworld</p>';
And I want to search the string for the first URL that starts with youtube.com or youtu.be and store it in variable $first_found_youtube_url.
How can I do this efficiently?
I can do a preg_match or strpos looking for the urls but not sure which approach is more appropriate.

Answer 1

I wrote this function a while back, it uses regex and returns an array of unique urls. Since you want the first one, you can just use the first item in the array.
function getUrlsFromString($string) {
$regex = '#\bhttps?://[^\s()<>]+(?:\([\w\d]+\)|([^[:punct:]\s]|/))#i';
preg_match_all($regex, $string, $matches);
$matches = array_unique($matches[0]);
usort($matches, function($a, $b) {
return strlen($b) - strlen($a);
});
return $matches;
}
Example:
$html = '<p>helloworld</p><p>helloworld</p>';
$urls = getUrlsFromString($html);
$first_found_youtube = $urls[0];
With YouTube specific regex:
function getYoutubeUrlsFromString($string) {
$regex = '#(https?:\/\/(?:www\.)?(?:youtube.com\/watch\?v=|youtu.be\/)([a-zA-Z0-9]*))#i';
preg_match_all($regex, $string, $matches);
$matches = array_unique($matches[0]);
usort($matches, function($a, $b) {
return strlen($b) - strlen($a);
});
return $matches;
}
Example:
$html = '<p>helloworld</p><p>helloworld</p>';
$urls = getYoutubeUrlsFromString($html);
$first_found_youtube = $urls[0];

Answer 2

you can parse the html with DOMDocument and look for youtube url's with stripos, something like this
$html = '<p>helloworld</p><p>helloworld</p>';
$DOMD = #DOMDocument::loadHTML($html);
foreach($DOMD->getElementsByTagName("a") as $url)
{
if (0 === stripos($url->getAttribute("href") , "https://www.youtube.com/") || 0 === stripos($url->getAttribute("href") , "https://www.youtu.be"))
{
$first_found_youtube_url = $url->getAttribute("href");
break;
}
}
personally, i would probably use
"youtube.com"===parse_url($url->getAttribute("href"),PHP_URL_HOST)
though, as it would get http AND https links.. which is probably what you want, though strictly speaking, not what you're asking for in top post right now..

Answer 3

I think this will do what you are looking for, I have used preg_match_all simply because I find it easier to debug the regexes.
<?php
$html = '<p>helloworld</p><p>helloworld</p>';
$pattern = '/https?:\/\/(www\.)?youtu(\.be|\com)\/[a-zA-Z0-9\?=]*/i';
preg_match_all($pattern, $html, $matches);
// print_r($matches);
$first_found_youtube = $matches[0][0];
echo $first_found_youtube;
demo - https://3v4l.org/lFjmK