title: Receive Error "Polymer::Attributes: couldn't decode Array as JSON" using iron-ajax in Polymer
body: <p>I am trying to use <i>iron-ajax</i> to call an array and display the data on a simple page.  Every time I do so, I receive the following error in the console:</p>
  
  <pre><code>Polymer::Attributes: couldn't decode Array as JSON
  </code></pre>
  
  <p>I have searched everywhere but unfortunately have not found a solution.  I am utilizing two pages:</p>
  
  <p>datasource-test.cfm - which returns the following JSON</p>
  
  <pre><code>[
  {
  LNAME: "Nanners",
  GRADE: 10,
  GENDER: "F",
  ID: 88796848,
  BIRTHDAY: "3/4/1999",
  FNAME: "Nullie"
  },
  {
  LNAME: "Nulled",
  GRADE: 11,
  GENDER: "M",
  ID: 88485738,
  BIRTHDAY: "4/25/1997",
  FNAME: "Nullan"
  },
  {
  LNAME: "Nullen",
  GRADE: 9,
  GENDER: "M",
  ID: 88659685,
  BIRTHDAY: "4/6/2000",
  FNAME: "Nuller"
  }
  ]
  </code></pre>
  
  <p>datasource-test.html</p>
  
  <pre><code>&lt;html&gt;
  &lt;head&gt;
  &lt;script src="elements/webcomponentsjs/webcomponents-lite.min.js"&gt;&lt;/script&gt;
  &lt;link rel="import" href="elements/iron-ajax/iron-ajax.html"&gt;
  &lt;link rel="import" href="elements/polymer/polymer.html"&gt;
  &lt;/head&gt;
  &lt;body&gt;
  &lt;iron-ajax auto url="datasource-test.cfm" handle-as="json" last-response="{{response}}"&gt;&lt;/iron-ajax&gt;
  &lt;template is="dom-repeat" items="{{response}}"&gt;
  &lt;/template&gt;
  &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>
  
  <p>When I try and load datasource-test.html, that's when I receive my error. Is there any way I can successfully call and load elements for the response without Polymer throwing an error?</p>