Regex to match placeholders that contain HTML within them - php

Question

I have placeholders that users can insert into a WYSIWYG editor (which contains HTML code). Sometimes when they paste from apps like Word etc it injects HTML within them.
Eg: It pastes %<span>firstname</span>% instead of %firstname%.
Here is an example of my regex code:
$html = '
<p>%firstname%</p>
<p>%<span>firstname</span>%</p>
<p>%<span class="blah">firstname</span>%</p>
<p>%<span><span>firstname</span></span>%</p>
<p>%<span><span><span>firstname</span></span></span>%</p>
<p>%<span class="blah"><span>firstname</span></span>%</p>
<div>other random <strong>HTML</strong> that needs to be preserved.</div>
';
preg_match_all(
'/\%(?![0-9])((?:<[^<]+?>)?[a-zA-z0-9_-]+(?:[\s]?<[^<]+?>)?)\%/U',
$html,
$matches
);
echo '<pre>';
print_r($matches);
echo '</pre>';
Which outputs the following:
Array
(
[0] => Array
(
[0] => %firstname%
[1] => %firstname%
[2] => %firstname%
)
[1] => Array
(
[0] => firstname
[1] => firstname
[2] => firstname
)
)
As soon as there is more than one span inside the placeholder it doesn't work. I'm not quite sure what to adjust in my regex.
/\%(?![0-9])((?:<[^<]+?>)?[a-zA-z0-9_-]+(?:[\s]?<[^<]+?>)?)\%/U
How would I achieve this?

Answer 1

Try this Regex. It should help you out!
/\%(?![0-9])(?:<[^<]+?>)*([a-zA-z0-9_-]+)(?:[\s]?<\/[^<]+?>)*\%/U

Answer 2

You could use a parser and the textContent property if it is a WYSIWYG editor anyway:
<?php
$html = '
<p>%firstname%</p>
<p>%<span>firstname</span>%</p>
<p>%<span class="blah">firstname</span>%</p>
<p>%<span><span>firstname</span></span>%</p>
<p>%<span><span><span>firstname</span></span></span>%</p>
<p>%<span class="blah"><span>firstname</span></span>%</p>
<div>A cool div with %firstname%</div>
<span>And a very neat span with %firstname%</span>';
$dom = new DOMDocument();
$dom->loadHTML($html);
$xpath = new DOMXPath($dom);
# query only root elements here
$containers = $xpath->query("/*");
foreach ($containers as $container) {
echo $container->textContent . "\n";
}
?>
This outputs %firstname% a couple of times, see a demo on ideone.com.

Answer 3

Do you really need a regex for this? You could have simply used strip_tags() here.
Try this:
echo strip_tags($html);