Thank you, Dimitar.
I'm happy with the ajax and datasource side of things - that's very clean and simple. Good work!
On the popup edits, what I need is the ability to edit more fields than are displayed in the grid, and in a custom layout. In your demo, the four fields in the grid are edited in an auto-generated popup, and that's that. It's a nice little demo, but more often than not, apps need to edit much more data than is shown in the grid.
So I was hoping there might be a "load" event for a popup edit template when the user clicks the edit button for a row. The row's entity's ID is fired into the controller or API, a view model is returned and bound to the template. User does his thing editing it, and the view model is posted back as per a regular MVC edit.
What I wanted in the template was the ability to query the controller for data to populate drop-downs, for example, when editing a foreign key field. So a product's category will likely be an ID which references a CategoryID and CategoryName in another table, so the user would start typing in the category name dropdown and the dropdown control is populated via ajax until he clicks on the one he wants, setting the ID field in the view model.
Essentially the template is a regular MVC form, with some pre and post edit events handled by the grid.
Did that make sense?!! Basically a much fuller and real-world version of the demos you have.