I'm having a lot of difficulty getting the cascading comboboxes functionality to work. These work as expected when they are independent, but the Child box remains disabled when set up as a cascade (uncommenting the CascadeFrom line). Any help would be appreciated!
When serverfiltering is enabled, the filtering of the data depends on the implementation of the remote service.
In order to retrieve only the child items according to the selected parent, you will need to send the data about the selected parent to the server. You could use the transport.read.data, which allows you to send additional parameters to the server. Here is a Demo which shows the cascading functionality in ASP.Net MVC projects.
I have prepared also a sample project where the ComboBox cascading functionality is demonstrated. Note, that dependencies are deleted due to the size limits.
I hope this will help.
When serverfiltering is not explicitly enabled, the filtering will be performed client-side.
Attached you will find the modified sample project. In the Index.cshtml I have commented the unnecessary configurations.