title: How to change opacity with ngstyle?
body: <p>I have in controller so far:</p>
  
  <pre><code>$scope.currentPage = 0;
  </code></pre>
  
  <p>Now, without any additional code (<strong>method</strong>) in controller I want to set opacity <code>0.4</code> on image when  <code>currentPage ==0</code></p>
  
  <p>So I wrote:</p>
  
  <pre><code>&lt;div ng-controller="ctrlRead"&gt;
    &lt;div class="pagination no-margin "&gt;
      &lt;ul&gt;
        &lt;li ng-class="{disabled: currentPage == 0}"&gt;
           &lt;a href=""
            ng-class="{disabled: currentPage == 0}"&gt;
               &lt;i class="icon-fast-backward"
               ng-style="{opacity : (currentPage == 0)?'0.4':'1'}"&gt;
               &lt;/i&gt;
          &lt;/a&gt;
        &lt;/li&gt;
      &lt;/ul&gt;
    &lt;/div&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>But I get error:</p>
  
  <pre><code>Unexpected next character  at columns 29-29 [?] in expression [{opacity : (currentPage == 0)?'0.4':'1'}]
  </code></pre>
  
  <p><kbd><a href="http://jsfiddle.net/SAWsA/855/">Fiddle</a></kbd></p>
  
  <p>Do I miss something?</p>
  
  <p>Thank you,</p>
  
  <p><strong>[EDIT]</strong></p>
  
  <p>I can write <code>ng-style="myOpacity"</code></p>
  
  <p>and in controller:</p>
  
  <pre><code>$scope.myOpacity = {
      'opacity': ($scope.currentPage == 0)?0.4:1
  };
  </code></pre>
  
  <p>But it demands additional code in controller     </p>