title: onBeforeRendering function runs twice
body: <p>
  The <code>onBeforeRendering()</code> function yesterday ran one when app starts, today in the morning it runs twice. And I have no idea why.</p>
  
  <p>Here is the relavant part of the controller:</p>
  
  <pre class="lang-js prettyprint-override"><code>...
  return Controller.extend("com.qv.controller.Household", { 
      variable: 1,
      onBeforeRendering: function() {
          console.log("variable",variable);
          this.variable++;
          ......
      },
      .......
  }
  </code></pre>
  
  <p>In the console I see:</p>
  
  <blockquote>
    <p>variable  1             controller_name.controller.js:14:7 </p>
    
    <p>variable  2             controller_name.controller.js:14:7</p>
  </blockquote>
  
  <p>I navigate to this view from another view if it matters.</p>
  
  <p>In a new project it runs once. I don't have any "rerender" things or stuff like that. How it is possible at all and how do I fix this?</p>
  
  <p>Thank you.</p>