title: Angular-Material , AngularJS , TypeScript , Javascript , ng-controller not accessible within my md-dialog
body: <p>I have a problem in my code, I'm trying to call on my users with a ng-controller in (declared on index like this ' ng-controller="mainController as vm" ') and I can use this in my code to access the user and to get his email and images. 
  But now I want to be able to open a md-dialog when you click my image , so the image can be enlarged in the dialog, my dialog opens but I cant access my controller (vm) to say what image he has to show.</p>
  
  <p>This opens the image in my content page:</p>
  
  <pre><code>&lt;img src="{{vm.selected.item4}}" /&gt;
  </code></pre>
  
  <p>works perfectly btw</p>
  
  <p>and this is how I open the dialog:</p>
  
  <pre><code>&lt;md-button ng-click="vm.showDialog($event)" &gt;
              &lt;img src="{{vm.selected.item1}}"/&gt;
  &lt;/md-button&gt;
  </code></pre>
  
  <p>My dialog opens but it won't show the image...
  Has anyone got an idea of how to resolve this problem?</p>
  
  <p>(if my topic or question isn't formed correctly I'm sorry in advance , I'm new to this so correct me if something isn't like it's suppose to...)</p>