So, I am using UI for ASP.NET MVC Q1 2015. I have 3 DDLs, configured to populate their data remotely(from action method inside a controller) using DataSource/Read action AJAX pattern.
I have some custom business logic I need to implement: when something gets changed in the 1st DDL, I have to do some custom calculations that may potentially involve what it has been selected in 2nd DDL so I can eventually change the selected values in the 3rd DDL.
So this here has nothing to do with datasource filtering or custom cascading.
My issue/concern here is: how can I do any such calculations/alterations of the other DDLs from inside a 'Changed' event handler in the 1st one safely, given all 3 are populated asynchronously? I mean, how can I be sure that when inside the Changed event handler in 1st DDL, data for 2nd & 3rd DDL had been fully loaded so I can use them in calculations and/or change the Selected value for those DDLs?