If cube data source for widget is deleted view management breaks

[Scott Wiltshire]

Bug Description If a cube which is used as data source for a widget is deleted then it is not possible to change the data source (select another cube) in the view management app for any widget that had the cube mapped. The view management breaks and just "spins" when the widget is selected.

To Reproduce Make a back end change to the data source for a widget by editing the datasource directly in }ElementAttributes_}APQ C3 Canvas View. e.g. add some random characters to a existing cube name. Then in the UX open the view settings for the widget. The view management app will hang as it is unable to read the dimensions for a cube which does not exist.

Expected behaviour If a widget has a bad cube as datasource mapping then the view management shoudl not break. The user should be able to select a new datasource for the view.

[tomer ganz]

was when moved to content store