PHP - Wrap multiple instances with preg_replace - php

Question

I have a string like this:
'<img src="image1.jpg"><img src="image2.jpg"><img src="image3.jpg">
<img src="image4.jpg"><img src="image5.jpg">'
I'd like to come to:
'<div class="slide"><img src="image1.jpg"><img src="image2.jpg"></div>
<div class="slide"><img src="image2.jpg"><img src="image3.jpg"></div>
<div class="slide"><img src="image3.jpg"></div>'
So basically I'd like to apply a preg_replace to wrap every 2 elements in a DIV.
I searched the forum and found some tips that I tried:
$pattern = '/(<img[^>]*class=\"([^>]*?)\"[^>]*>)+/i';
$replacement = '<div class="slide">$1</div>';
$content = preg_replace($pattern, $replacement, $content);
and
$pattern = '/(<img[^>]*class=\"([^>]*?)\"[^>]*>){2,}/i';
$replacement = '<div class="slide">$1</div>';
$content = preg_replace($pattern, $replacement, $content);
But it doesn't work...
Any idea, guys?
Thank you!

Answer 1

Use DomDocumen object to do it:
$str = '<img src="image1.jpg"><img src="image2.jpg"><img src="image3.jpg">
<img src="image4.jpg"><img src="image5.jpg">';
$dom = new DomDocument;
$dom->loadHTML($str);
$imgs = $dom->getElementsByTagName('img');
$i = $imgs->length;
$cur = 0;
$res = new DomDocument;
while ($i >= 2) {
$div = $res->createElement('div');
$div->setAttribute("class","slide");
$res->appendChild($div);
$div->appendChild($res->importNode($imgs->item($cur++)));
$div->appendChild($res->importNode($imgs->item($cur++)));
$i -= 2;
}
if($i) $res->appendChild($res->importNode($imgs->item($cur++)));
echo $res->saveHTML();
// <div class="slide"><img src="image1.jpg"><img src="image2.jpg"></div><div class="slide"><img src="image3.jpg"><img src="image4.jpg"></div><img src="image5.jpg">

Answer 2

Here is working example:
<?php
$content = '<img src="image1.jpg"><img src="image2.jpg">
<img src="image3.jpg"><img src="image4.jpg">
<img src="image5.jpg">';
$pattern = '/((<img[^>]*src=\"([^>]*?)\"[^>]*>\s*){2,2})/i';
$replacement = '<div class="slide">$1</div>';
$content = preg_replace($pattern, $replacement, $content);
echo $content;
It is your second example, but with 4 fixes:
class -> src
added block () to catch 2 items
fixed quantity {2,} -> {2,2} (change it to {1,2} if you want to catch last one img tag)
\s* added to catch spaces and line breaks between img tags