PHP: replace relative urls to absolute urls in a textarea

Question

I would like to replace relative URLs to absolute URLs in a textarea. So something like this:

/somefolder/somefile 

Is replaced to:

http://www.mysite123.com/somefolder/somefile

I have this replace function to do the job:

$replaceStrs = array('href=/', "href='/", 'href="/');
$datdescription = str_ireplace($replaceStrs, 'href="http://www.' . $domain . "/", $datdescription);

1. The problem is that it needs a / in the start of the value and therefore a URL like href=somefolder/somefile would not be replaced.
2. I also would like it to work if there are spaces before or / and after the = in the href part.

Point 1 is most important. Can you help to improve this?

I have seen PHP examples that replaces relative URLs to absolute URLs like this one .

But the requirement is that the relative URL is known / found but in my case I have not managed this part (I am working with replacing all URLs in a textarea).

Answer 1

PHP:

function expand_links($link) {
    return('href="http://example.com/'.trim($link, '\'"/\\').'"');
}
$textarea = preg_replace('/href\s*=\s*(?<href>"[^\\"]*"|\'[^\\\']*\')/e', 'expand_links("$1")', $textarea);

I also changed the regex to work with either double quotes or apostrophes.

Answer 2

Why all this fuss when a PHP function can already do this for you?

http://php.net/manual/en/function.http-build-url.php

PS: It seems it's only available on PECL. I just tested my Hostgator VPS (standard CentOS 5 repos) as well as my test WAMP environment, and it seems to be available on both.

NB: Also, you REALLY shouldn't blindly replace HTML fragments. First of all, it may not work eventually (encoding issues), secondly, it may add security issues to your code.

Answer 3

I expanded Mihai Stancu answer for you!

---

<?php 
function expand_hrefs($link, $url) {
    return('href="http://'.$url.'/'.trim($link, '\'"/\\').'"');
}

function expand_srcs($link, $url) {
    return('src="http://'.$url.'/'.trim($link, '\'"/\\').'"');
}

$html = preg_replace('/href\s*=\s*(?<href>"[^\\"]*"|\'[^\\\']*\')/e', 'expand_hrefs("$1", "'.$url.'")', $html);
$html = preg_replace('/src\s*=\s*(?<src>"[^\\"]*"|\'[^\\\']*\')/e', 'expand_srcs("$1", "'.$url.'")', $html);
?>

This is MY first answer..

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