title: POST data not appearing in CakePHP controller
body: <p>I'm using AJAX on a knockout.js form to post some information that CakePHP should receive, however, Cake doesn't seem to find anything. Also, the alert isn't appearing despite a 200 status (OK) from the POST.</p>
  
  <p>Here's the AJAX</p>
  
  <pre><code>$.ajax({  
            url: "/orders/finalize_payment",  
            type: "POST",  
            dataType: "json",  
            contentType: "json",  
            data: JSON.stringify({"customer": customer_id}),  
            success: function(){              
              alert("success");  
            }
      }); 
  </code></pre>
  
  <p>Here's the corresponding action in the orders controller. Right now, I completely stripped it to just the bare minimum.</p>
  
  <pre><code>function finalize_payment($id = null){
      $this-&gt;layout = false;
      $this-&gt;autoRender = false;
      if($this-&gt;request-&gt;is('post')){ //the user has submitted which status to view
          print_r($this-&gt;request-&gt;data);
              echo "test"; //just to make sure it's reaching this point
      }
  }
  </code></pre>
  
  <p>When I open up the network tab in chrome, it shows the request payload as</p>
  
  <pre><code>customer: 1
  </code></pre>
  
  <p>The POST shows as success, status 200. I checked the response headers and it just shows</p>
  
  <pre><code>array
  (
  )
  test
  </code></pre>
  
  <p>Despite chrome showing a payload being sent, CakePHP isn't finding it apparently. </p>
  
  <p><strong>Update</strong></p>
  
  <p>I changed the request from AJAX to $.post and it worked. I still have no clue why</p>
  
  <pre><code>$.post("/orders/finalize_payment",{"customer_id":customer_id},function(data){
          alert('success');
   });
  </code></pre>