title: angular directive parameters
body: <p>I want to have a directive with a parameter so that I can render it as follows:</p>
  
  <pre><code>&lt;ng-polite-captcha name="@Const.NoCaptchaResponseField"
                     challenge=" @Const.NoCaptchaChallengeField"&gt;&lt;/ng-polite-captcha&gt;
  </code></pre>
  
  <p>Here's my directive definition:</p>
  
  <pre><code>app.directive('ngPoliteCaptcha', function() {
      return {
          restrict: 'E',
          replace: true,
          scope: {
              name: '@',
              challenge: '@'
          },
          template: '&lt;input type="hidden" name="{{ name }}" value="{{ value }}" /&gt;',
          controller: ['$scope', function ($scope) {
              var response = angular.element('[name="' + $scope.challenge + '"]');
              if (response &amp;&amp; response.val())
                  $scope.value = response.val().split('').reverse().join('');
          }]
      };
  });
  </code></pre>
  
  <p>The rendered input looks like this:</p>
  
  <pre><code>&lt;input type="hidden" value="..." name="nocaptcha_response " challenge="nocaptcha_challenge"&gt;
  </code></pre>
  
  <p>How do I make angular to stop rendering the "challenge" attribute on the input? it's not in the template.. it's transfered from the markup in chich I call the directive </p>