title: Uncaught ReferenceError: Class is not defined
body: <p>I am following this sample <a href="http://phloxblog.in/angulard3/start.html#N" rel="nofollow"><code>Create bar chart</code></a>, but there is an error saying <code>Uncaught ReferenceError: Class is not defined</code>.</p>
  
  <p>I have included the library for prototype.js</p>
  
  <pre><code> &lt;script src="https://ajax.googleapis.com/ajax/libs/prototype/1.7.2.0/prototype.js"&gt;&lt;/script&gt;
  </code></pre>
  
  <p>Here is the code,</p>
  
  <p><strong>HTML</strong>:</p>
  
  <pre><code>&lt;div id="d3area" angulard3-ear-chart datajson="'sample.json'" xaxis-name = "" xaxis-pos= "" yaxis-name="'Price/($)'" yaxis-pos="12" d3-format="'%d-%b%y'"
  </code></pre>
  
  <p>And directive,</p>
  
  <p><strong>App.Js</strong>:</p>
  
  <pre><code>var BarGraph = Class.create({
  initialize: function(datajson,xaxisName,xaxisPos,yaxisName,yaxisPos,d3Format) {
  this.datajson = datajson;
  this.xaxisName = xaxisName;
  this.xaxisPos = xaxisPos;
  this.yaxisName = yaxisName;
  this.yaxisPos = yaxisPos;
  this.d3Format = d3Format;
  },
  workOnElement: function(element) {
  
  },
  </code></pre>