How to write a complex regexp condition?

Question

PHP

How to turn it

<chunk></chunk>
<chunk></chunk>
<chunk></chunk>

in it?

<span data-element="chunk" name="chunk.name.test"></span>
<span data-element="chunk" name="tpl.test.name"></span>
<span data-element="chunk" name="test"></span>

Answer 1

<?php

$str = '<chunk></chunk><chunk></chunk><chunk></chunk>';
$replace = '<span data-element="$1" name="$3">$2</span>';

echo preg_replace("/<(\w+)>(\[\+)\]\])<\/(\w+)>/u", $replace, $str);

Conclusion:

$ php replace.php
<span data-element="chunk" name="chunk.name.test"></span>
<span data-element="chunk" name="tpl.test.name"></span>
<span data-element="chunk" name="test"></span>

$allow option:

<?php

$str = '<chunk></chunk><chunk></chunk><chunk></chunk>';
$replace = '<span data-element="$1" name="$3">$2</span>';
$allow = 'chunk.name.test|test';

echo preg_replace("/<(\w+)>(\[\[[$!]+((?:{$allow}))\]\])<\/(\w+)>/u", $replace, $str);

Conclusion:

$ php replace.php
<span data-element="chunk" name="chunk.name.test"></span>
<chunk></chunk>
<span data-element="chunk" name="test"></span>

Play around here:
https://regex101.com/r/gI5rE3/1