Inserting a model at correct index in Marionette.CollectionView appendHtml

CollectionView.appendHtml.js

/*
 * @author Dave Taylor https://github.com/davetayls
 * @see http://davetayls.me/blog/2013/10/03/model-index-in-marionette-collectionview-appendhtml/
 */

Marionette.CollectionView.extend({
    appendHtml: function(collectionView, itemView, index) {
      var childAtIndex;
      
      // could just quickly
      // use prepend
      if (index === 0) {
        return collectionView.$el
          .prepend(itemView.el);
        
      } else {
      
        // see if there is already
        // a child at the index
        childAtIndex = collectionView.$el
          .children().eq(index);
        if (childAtIndex.length) {
            return childAtIndex
              .before(itemView.el);
        } else {
            return collectionView.$el
              .append(itemView.el);
        }
      }
    }
});