title: Second level sorting using smart table?
body: <p>I have a paginated table using a smart table. I want to sort using first the status and then the code. I can't use orderBy from AngularJS because it will order the elements of each page, not all. And st-sort-default of smart table orders only for one column.</p>
  
  <pre><code>&lt;table st-table="lista.displayedPublications" st-safe-src="lista.publications"&gt;
        &lt;thead&gt;
            &lt;tr&gt;
                 &lt;th st-sort="publication.status" &gt;STATO&lt;/th&gt;
                 &lt;th st-sort="publication.communicationCode"&gt;TREAT CD&lt;/th&gt;                      
                 &lt;th&gt; ... &lt;/th&gt;
            &lt;/tr&gt;
        &lt;/thead&gt;
        &lt;tbody&gt;
            &lt;tr ng-repeat="publication in lista.displayedPublications"&gt;
                 &lt;td&gt;{{publication.status}}&lt;/td&gt;
                 &lt;td&gt;{{publication.communicationCode}}&lt;/td&gt;
                 &lt;td&gt;...&lt;/td&gt;                 
             &lt;/tr&gt;
         &lt;/tbody&gt;
               &lt;tfoot&gt;
                  &lt;tr&gt;
                      &lt;td&gt;
                          &lt;div st-template="ListaTreatement/pagination.html" st-pagination="" st-items-by-page="10"&gt;&lt;/div&gt;
                      &lt;/td&gt;
                   &lt;/tr&gt;
                &lt;/tfoot&gt;
    &lt;/table&gt;
  </code></pre>
  
  <p>In the controller:</p>
  
  <pre><code>public publications: PublicationExtended[];
  public displayedPublications = [].concat(this.publications);
  constructor(...){
       new Api($http).getList(me.comunicationType, me.comunicationStatus).then(
          function(response : angular.IHttpPromiseCallbackArg&lt;PublicationExtended[]&gt;) {
              me.publications = response.data;
          }
  }
  </code></pre>