title: Cascading ComboBox drops model binding after setting initial value empty
body: <p><strong>My scenario:</strong></p>
  
  <p>Cascading dropdowns ending with ComboBox (partial view) used in master->details scenario with kendo grid</p>
  
  <p>ddl->ddl->ddl->cb</p>
  
  <p><strong>Goal:</strong></p>
  
  <ol>
  <li>On page load DropDownLists are being initialized with data one by one
  with some default value, and the ComboBox should stay empty</li>
  <li>On grid selecteditemchanged partial view is being filled with data and ComboBox should display appropriate element.</li>
  </ol>
  
  <p>In my case it works as follows:</p>
  
  <ol>
  <li>on page load ComboBox displays '0' (null I suppose?)</li>
  <li>on selection change it blinks with selected <strong>value</strong> which is basically <em>model.Id</em> and it shows appropriate <strong>text</strong>  </li>
  </ol>
  
  <p>Or if I clear <em>text/value</em> propery of kendoComboBox when parent DropDownList data is loaded:</p>
  
  <ol>
  <li>on page load ComboBox is empty</li>
  <li>on selection change it blinks like above but its stays empty</li>
  </ol>
  
  <p>If I change ComboBox control into 4th DropDownList it still "blinks" but all in all works fine. Selected item from model is preserved correctly in the DropDown.</p>
  
  <p>I cannot provide a complete example because it's too heavy but I don't think it's necessary.</p>
  
  <p>This is how the lists data is cascading. On parent's DataBound event  .dataSource.read() method of child is called. Nothing fancy.</p>
  
  <pre><code>function ParentProductIdDataBound() {
      var dropdownlist = $("#ParentProductId").data("kendoDropDownList");
  
      if (dropdownlist.value()) {
          OnParentProductIdChange();
      }
  }
  
  function ParentProductIdChange() {
      OnParentProductIdChange();
  }
  
  function OnParentProductIdChange() {
      var productcombobox = $("#ProductId").data("kendoComboBox");
      productcombobox.text("");     &lt;- empty until combo is populated
      productcombobox.value("");
      productcombobox.enable(true);  &lt;- enable combo
      productcombobox.dataSource.read();  &lt;- populate combo
  }
  </code></pre>
  
  <p>and here is the code of combo itself</p>
  
  <pre><code>@(Html.Kendo().ComboBox()
                .Name("ProductId")
                .DataTextField("Text")
                .DataValueField("Value")
                .AutoBind(false)
                //.Text(Model.ProductId == 0 ? " " : Model.ProductName)
                .DataSource(source =&gt;
                {
                    source.Read(read =&gt;
                    {
                        read.Action("GetMeansOfProduction", "DemandForMeansOfProduction", new { level = 3 }).Data("onProductComboBoxAdditionalData");
                    })
                          .ServerFiltering(false);
                })
                .Events(e =&gt;
                {
                    e.Change("ProductIdChange");
                    e.DataBound("ProductIdDataBound");
                })
          )
  </code></pre>
  
  <p>It looks like:</p>
  
  <ol>
  <li>Whenever the ComboBox is not populated it displays directly model value which it is binded to (Id), even if the model is empty -> thats the '0' from first case - and I want it to wait for data</li>
  <li>If I set the <em>value</em> and/or <em>text</em> of ComboBox empty it looses binding to model and after it is populated with data it doesn't know which item should be selected...</li>
  </ol>
  
  <p>Ideas of solution?</p>