title: How to set HTML5 attributes like 'required' using a Slim template
body: <p>I m laying out a form using the <a href="http://slim-lang.com" rel="noreferrer">Slim</a> template language and want to add the <code>required</code> attribute to my input.</p>
  
  <pre><code>input#first_name(required name="first_name" type="text" pattern="^[A-Z][a-z]+$")
  </code></pre>
  
  <p>However the HTML that is generated from this ends up being</p>
  
  <pre><code> &lt;input id="first_name" name="first_name" pattern="^[A-Z][a-z]+$" required="" type="text" /&gt;
  </code></pre>
  
  <p>And that's not what I need.</p>
  
  <p>I've gone through the docs but can't see any way with Slim to add a standalone html5 attribute.</p>
  
  <p>Likewise adding the <code>data-abide</code> attribute to the <code>form</code> tag (as required by the Zurb Foundation framework) fails.</p>
  
  <pre><code>form.custom(data-abide method="POST" action="/registration")
  </code></pre>
  
  <p>leads to</p>
  
  <pre><code>&lt;form action="/registration" class="custom" data-abide="" method="POST"&gt;
  </code></pre>
  
  <p>Which the Zurb scripts ignore.</p>
  
  <p>What am I missing?</p>