title: How to extract angular raw code from argument in directive and render it
body: <p>Not sure, how to describe this question more. So there is simple code and jsfiddle</p>
  
  <p>html</p>
  
  <pre><code>&lt;div&gt;
    &lt;span format="the value is: {{value||'no-val'}}" value="100" my-test&gt;&lt;/span&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>and javascript</p>
  
  <pre><code>App.directive('myTest', function() {
    return {
        restrict: 'A',
        replace: true,
        scope: {
            format: '@'
        },
        template: "&lt;span&gt;{{format}}&lt;/span&gt;",
        link: function($scope, element, attrs) {
            $scope.value = attrs.value
       }
    }
  })
  </code></pre>
  
  <p><a href="http://jsfiddle.net/VhvEy/2" rel="nofollow">http://jsfiddle.net/VhvEy/2</a></p>
  
  <p>My expectation <code>&lt;span&gt;the value is: 100&lt;/span&gt;</code></p>
  
  <p>Reality <code>&lt;span&gt;the value is: no-val&lt;/span&gt;</code></p>
  
  <p>Thanks for explanation!</p>