title: How do I filter Smarty variable to output only numbers?
body: <p>Fairly simple question, but I am new to regular expressions and smarty templates, and I can't seem to figure out how to get this working in my smarty template. </p>
  
  <p>Basically, I have smarty string that can contain string values like:</p>
  
  <pre><code>Home Page Layout 1-1
  Home Page Layout 1-2
  Home Page Layout 2-1 
  etc..  
  </code></pre>
  
  <p>I want to extract just the integers from the string so that the output is as followed:</p>
  
  <pre><code>11
  12
  21
  </code></pre>
  
  <p>As you can see, I'm removing everything but the integers.  I tried doing the following after searching around, but it doesn't work or output anything.  </p>
  
  <pre><code>{$SelectHomePageLayout|regex_replace:'[^0-9]+':''}
  </code></pre>
  
  <p>Fairly simple but I'm just not sure what I'm doing wrong.  </p>