title: angularjs make serial actions by condition
body: <p>i'd like to do user friendly action at my app.
  The issue is: 
  I have one button. When user 'mousedown' on it, i send ajax query to server to get some info. What i want is to show that info <em>only</em>  after user 'mouseup' on this button. In other words, when he releases mouse button. 
  The problem is that user can release mouse button before or after server answers to my ajax call, by i still want to show info only after release button.</p>
  
  <p>I think i can do this with deferred stuff, by i don't have a lot experience in this. Can you give me some info, how to do this? </p>
  
  <p>Example code:</p>
  
  <pre><code>.html
  &lt;input type='button' ng-start='start()' ng-end='end()' &gt;
  
  .js
  $scope.start = function(){
      $http.get(url, data).success(function(result){})
  }
  $scope.end = function(){
      //show result from first function
  }
  </code></pre>