this._dataSource._releaseBinding(this); in ListBinding throws when _releaseBinding is not defined

Question

How can that happen?

I dynamically switch the itemDataSource of a LV like this:

this.viewModel.bind('dataSource', function() {
        var listView;
        listView = document.getElementById('itemList').winControl;
        if (_this.viewModel.groupingCriterion === 'None') {
          WinJS.UI.setOptions(listView, {
            itemDataSource: _this.viewModel.dataSource,
            oniteminvoked: _this.documentItemInvoked,
            itemTemplate: doo.ui.renderers.documentItemRenderer,
            selectionMode: 'multi'
          });
        } else {
          WinJS.UI.setOptions(listView, {
            itemDataSource: _this.viewModel.dataSource,
            itemTemplate: doo.ui.renderers.filterGroupItemRenderer(_this.viewModel.groupingCriterion),
            oniteminvoked: _this.groupItemInvoked,
            selectionMode: 'none'
          });
        }
      });

during the setOptions call the LV itemdata manager release() is called and in turn wants to call _releaseBinding on the datasource.

My datasource is either a BindingList or a custom datasource modeled after the Bing custom datasource sample (VirtualizedDataSource).

Is switching datasources not allowed when the LV has been already populated?

Answer 1

nevermind. Got it solved: The incoming datasource was a bound property, not properly unwrapped.

Answer 2

Just to clarify, in order to "unwrap" a bound property, use the backingData member on your property. So in this case:

{
    ...
    itemDataSource: _this.viewModel.dataSource.backingData,
    ...
}