Grab URL within a string which contains HTML code

Question

I have a string, for example:

$html = '<p>hello<a href="https://www.youtube.com/watch?v=7HknMcG2qYo">world</a></p><p>hello<a href="https://youtube.com/watch?v=37373o">world</a></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.

The appropriate thing to do, would probably be to use a parser and parse it as what it is, HTML ? — adeneo
– adeneo, Commented Dec 23, 2015 at 23:38
@adeneo Can you please elaborate? I don't understand your approach. English is not my first language and I don't pickup on technical terms that easily. — Henrik Petterson
– Henrik Petterson, Commented Dec 23, 2015 at 23:39

h2ooooooo · Accepted Answer · 2015-12-24 00:04:02Z

4

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>hello<a href="https://www.youtube.com/watch?v=7HknMcG2qYo">world</a></p><p>hello<a href="https://youtube.com/watch?v=37373o">world</a></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>hello<a href="https://www.youtube.com/watch?v=7HknMcG2qYo">world</a></p><p>hello<a href="https://youtube.com/watch?v=37373o">world</a></p>';
$urls = getYoutubeUrlsFromString($html);
$first_found_youtube = $urls[0];

edited Dec 24, 2015 at 0:04

h2ooooooo

39.6k8 gold badges70 silver badges107 bronze badges

answered Dec 23, 2015 at 23:39

skrilled

5,3712 gold badges28 silver badges49 bronze badges

Sign up to request clarification or add additional context in comments.

10 Comments

Tyler Sebastian Over a year ago

@HenrikPetterson try this https?:\/\/(?:www\.)?(?:youtube.com\/watch\?v=|youtu.be\/)(.*) - the only capture group contains the video ID

Henrik Petterson Over a year ago

@TylerSebastian Please try the following to understand the problem: pastebin.com/6zS2fAus

Tyler Sebastian Over a year ago

Use (https?:\/\/(?:www\.)?(?:youtube.com\/watch\?v=|youtu.be\/)([a-zA-Z0-9]*)). regexr.com/3cfhn

skrilled Over a year ago

Thanks @TylerSebastian - updated answer to include your regex with a rewritten function.

h2ooooooo Over a year ago

Make sure you make your regex in-case-sensitive (#i) in case you get capital links like HTTP://WWW.WEBSITE.NET.

|

hanshenrik · Accepted Answer · 2015-12-24 00:39:54Z

you can parse the html with DOMDocument and look for youtube url's with stripos, something like this

$html = '<p>hello<a href="https://www.youtube.com/watch?v=7HknMcG2qYo">world</a></p><p>hello<a href="https://youtube.com/watch?v=37373o">world</a></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..

the_velour_fog · Accepted Answer · 2015-12-24 00:38:14Z

0

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>hello<a href="https://www.youtu.be/watch?v=7HknMcG2qYo">world</a></p><p>hello<a href="https://youtube.com/watch?v=37373o">world</a></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

answered Dec 24, 2015 at 0:38

the_velour_fog

2,1944 gold badges20 silver badges32 bronze badges

Collectives™ on Stack Overflow

Grab URL within a string which contains HTML code

3 Answers 3

10 Comments

Comments

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

10 Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related