title: how to append data to a model for a treeview in qml
body: <p>I have 2 qml tableviews. when i click on the 1st one i get an id from the selected row and then i filter the 2nd table based on that id.
  In qml i am doing like this(pseudocode):</p>
  
  <pre><code>TableView {
      .....
      onclick: {
         var id = table1model.getid(currentIndex)
         table2.model.clear
         for(index in sourceModel) {
             if (condition()) {
                 table2.model.append(index)
              }//end if
          }//end for
      }//end onclick
  }//end table1
  
  TableView {
      id: table2
      ....
  }
  </code></pre>
  
  <p>The problem is nothing gets displayed in table2 even if some items are added to the model. Can i append to a model an index from another model(they have the same structure, practically the table2 model is a subset of the sourceModel which is registered in context)?</p>