title: Ember.js: conditional input attribute
body: <p>In Ember's input helper, how can I show/hide attributes based on a condition?  For example, let's say I want to show <code>required="required"</code> if <code>isEditable</code> is true and <code>disabled="disabled"</code> otherwise.  Currently I have something like this:</p>
  
  <pre><code>{{#if isEditable}}
      {{input value=model.name required="required"}}
  {{else}}
      {{input value=model.name disabled="disabled"}}
  {{/if}}
  </code></pre>
  
  <p>...but it would be nice if I bind the attributes somehow instead.</p>