title: Ng-Tag-Input Directive not clearing value
body: <p>I am using <a href="http://mbenford.github.io/ngTagsInput/documentation/api#tagsInput" rel="nofollow">ngTagInput</a> directive for auto-suggestion. What I want is clear the auto-suggestion after suggestion is clicked. Though its clearing on first call of function but not on second. It is adding as tag on second function call. and I want to remove that.</p>
  
  <p>On Html,</p>
  
  <pre><code>&lt;tags-input ng-model="autoSongs"
          key-property="_id"
          display-property="name"
          add-from-autocomplete-only="true"
          replace-spaces-with-dashes="false"
          on-tag-adding="songAdded($tag)"
          on-tag-added="emptyScope()"
          template="tag-template"
          placeholder="type here to search for album..."
          on-tag-removed="songRemoved($tag)"&gt;
  &lt;auto-complete source="loadSongs($query)"
                 min-length="2"
                 debounce-delay="5"
                 max-results-to-show="10"
                 template="autocomplete-template"&gt;&lt;/auto-complete&gt;
  &lt;/tags-input&gt;
  </code></pre>
  
  <p>This way on controller,</p>
  
  <pre><code>$scope.loadSongs = function(query) {
          var autoFilter = 'name=' + query;
          return songService.autoSuggest(autoFilter, function(error, data) {
              if (error) {
                  toastr.error(error.message, 'Error');
                  return false;
              }
              return data;
          });
      };
  
      $scope.songAdded = function(query) {
          if ($scope.pushArray.checkbox.length === 0) {
              toastr.error('Select record to assign album.', 'Error');
              return false;
          }
          var songId = query._id,
              songName = query.name;
          videoService.assignSong(songId, $scope.pushArray.checkbox, function(err, resonse) {
              if (err) {
                  toastr.error(err.message, 'Error');
              } else {
                  $scope.emptyScope();
                  toastr.success('\'' + songName + '\' has been assigned to ' + resonse + ' records', 'Success');
                  $scope.pageChanged();
              }
          });
          return true;
      };
  
      $scope.emptyScope = function() { 
          $scope.autoSongs = null;
      };
  </code></pre>
  
  <p>Its not clearing value on second attempt. Can I use auto-suggestion with callbacks separately?</p>
  
  <p><a href="http://plnkr.co/edit/7nt3toEclsP5HXL7RadP?p=preview" rel="nofollow">plunker</a></p>