I'm currently using preg_replace_callback in PHP to parse html templates and replace place holders in the templates with content from the database.

All is good and working fine except where I have mutiple place holders that are the same. so my template looks like

<p>some text</p>
<h1>Resources 1</h1>
  {cms type="resource" id="1"}
    <a href="{link}">{title}</a>
  {/cms}
<p>some more text</p>
<h1>Resources 2</h1>
   {cms type="resource" id="2"}
    <a href="{link}">{title}</a>
  {/cms}
<p>lots more text</p> 

and the reg ex i'm using is:

'/{cms type="resource" id="([\d]*)"}([\s\S]*){\/cms}/'

But this identifies the first {cms type="resource" id="1"} block as the start of the block and the last {/cms}  as the end of the block returning everything in between:

<a href="{link}">{title}</a>
{/cms}
<p>some more text</p>
<h1>Resources 2</h1>
{cms type="resource" id="2"}
<a href="{link}">{title}</a>

Can you suggest how I can get to identify the first {/cms} s the end of the block and only return what is in a single block.

Any help greatfully appreciated.

Cheers

Mike
 

I believe adding a ? solves the problem but I'm not sure why:

/{cms type="resource" id="([\d]*)"}([\s\S]*?){\/cms}/

what does the ? in  ([\s\S]*?) do?

Used in this manner, the ? indicates a non-greedy matching.

A typical greedy match matches as much as possible.

So this regex: .*b

applied against this text:

aaaaaaaaaaaaaaaaaaaaaaaaaabaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaab

matches on the whole string:

aaaaaaaaaaaaaaaaaaaaaaaaaabaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaab

But: .*?b matches as little as possible, so it matches on:

aaaaaaaaaaaaaaaaaaaaaaaaaab

stopping as soon as the match can be completed.

Your ([\s\S]*) regex matches on all characters, so the ? modifies the regex to look for the shortest number of characters that allows the regex to complete the match (i.e. end with your closing tag)

Mike,

Also make sure that you don't have nested tags in the text - if you do then other techniques will be needed (as in using the 'recursive' operators).

Susan