title: Send null as a value in ngResource AngularJS
body: <p>I'm using AngularJS 1.2.1's ngResource and I'm trying to send <code>null</code> as a value in the parameters in a PUT request. Unfortunately, when it is set, Angular will ignore it the parameter and not send it. </p>
  
  <p>Here's some example code:</p>
  
  <pre><code>var User = $resource('/comments/:id', {id:'@id'}, {
    destroy: { method: 'PUT', params: {content: null} }
  });
  var user = User.destroy({id:123}, function() {});
  </code></pre>
  
  <p>Angular will instead ignore <code>content</code> and not send the key nor the null value.</p>
  
  <p>How can I make Angular send null?</p>