Question

Is it possible to use php to search a string for a file path pattern and then insert a new folder at a specified point?

<?php
$string = '<ul>
<li><a href="/folder1/folder-a/file-a.htm">Link Text a</a></li>
<li><a href="/folder1/folder-b/file-b.htm">Link Text b</a></li>
<li><a href="/folder1/folder-c/file-c.htm">Link Text c</a></li>
<li><a href="/folder1/folder-d/file-d.htm">Link Text d</a></li>
</ul>';
?>

I don’t know in advance what folders-a,b,c,d or files-a,b,c,d will be called so I don’t see how I can use str_replace. I want in each case to insert a new folder before the file so that the outcome would look like this (the new-folder would have the same name in each case):

<?php
$string = '<ul>
<li><a href="/folder1/folder-a/new-folder/file-a.htm">Link Text a</a></li>
<li><a href="/folder1/folder-b/new-folder/file-b.htm">Link Text b</a></li>
<li><a href="/folder1/folder-c/new-folder/file-c.htm">Link Text c</a></li>
<li><a href="/folder1/folder-d/new-folder/file-d.htm">Link Text d</a></li>
</ul>';
?>

Thanks in advance for any feedback.

Answer 1

Assuming your HTML is always well formed this could work for you:

$string = '<ul>
<li><a href="/folder1/folder-a/file-a.htm">Link Text a</a></li>
<li><a href="/folder1/folder-b/file-b.htm">Link Text b</a></li>
<li><a href="/folder1/folder-c/file-c.htm">Link Text c</a></li>
<li><a href="/folder1/folder-d/file-d.htm">Link Text d</a></li>
</ul>';

$newString = preg_replace_callback(
  '/href="(.*?)"/i',
  function($matches) {
    return 'href="'.dirname($matches[1]).'/new-folder/'.basename($matches[1]).'"';
  },
  $string
);

echo $newString;

It is, as many people here will emphatically tell you, not a good idea to parse HTML with regex unless you know it to be well formed.