title: How to use ng-show with ng-repeat filtered?
body: <p>Here is my json (each object can be assigned to more than one category):</p>
  
  <pre><code>[
   { "title" : "titel1",
     "description" : "description1",
     "data": {
               "categoryList" : [
                                  { "categoryName" : "category1" }
                                 ]
              }
   },
   { "title" : "titel2",
     "description" : "description2",
     "data": {
               "categoryList" : [
                                  { "categoryName" : "category1" }
                                 ]
              }
   },
   { "title" : "titel3",
     "description" : "description3",
     "data": {
               "categoryList" : [
                                  { "categoryName" : "category2" }
                                 ]
              }
   },
   ... and so on
  ]
  </code></pre>
  
  <p>The div tags display the content for each category. I'd like to show the message "No content available", when no content is assigned to a category. No sure if something like 
  ng-show="!content. "this category" .length" would work.</p>
  
  <pre><code>&lt;!-- category 1 --&gt;
  &lt;div&gt;
    &lt;ul&gt;
      &lt;li ng-repeat="item in content | filter:{'data':'category1'}"&gt;
      {{item.title}} - {{item.description}}
      &lt;/li&gt;
      &lt;li ng-show="?????"&gt;No content available&lt;/li&gt; 
    &lt;/ul&gt;
  &lt;/div&gt;
  
  &lt;!-- category 2 --&gt;
  &lt;div&gt;
    &lt;ul&gt;
      &lt;li ng-repeat="item in content | filter:{'data':'category2'}"&gt;
      {{item.title}} - {{item.description}}
      &lt;/li&gt;
      &lt;li ng-show="?????"&gt;No content available&lt;/li&gt;  
    &lt;/ul&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>...</p>