title: How to use the parsley.js pattern tag?
body: <p>How do I add the <code>attr:data-parsley-pattern=""</code> tag correctly to a input?</p>
  
  <p>I wrote this:</p>
  
  <pre><code>&lt;input type="text" name="serialnr" id="serialnr" data-parsley-pattern="^[a-zA-Z]{4}[ -]?[a-zA-Z]{4}[ -]?[a-zA-Z]{4}[ -]?[a-zA-Z]{4}$"&gt;
  </code></pre>
  
  <p>But this does exactly nothing (No validation takes place at all while the other input are validated correctly). Do I have to add <code>data-parsley-required="true"</code>? (Which I did but that didn't help).
  I tested the regex with <a href="https://www.debuggex.com/" rel="nofollow noreferrer">https://www.debuggex.com/</a> so It shouldn't be a typo. What do I miss?</p>
  
  <p>I call parsley only via data-attributes. Does that matter maybe? </p>
  
  <p>Thank you.</p>