title: AngularJS, $window is not defined, how to?
body: <p>i am trying to do a redirect on a click</p>
  
  <pre><code>.controller('TestCtrl', function ($scope, $stateParams) {
      document.getElementById('next_question').addEventListener('click', function (e) {
          $window.location.href = '#/tab/category/1';
          return true;
      }, false);
  })
  </code></pre>
  
  <p>but i get <code>$window is not defined</code>. So... how would i get the <code>$window</code> or do a redirect a different way</p>
  
  <p>any ideas?</p>