Please let me know if WebCombo is bound to ISDataSource or in InitializeDataSource.
If the data is bound to ISDS, and the attribute is defined in the object, then it should be applicable because ISDS will read the attribute when it returns the custom obeject. But if the data is bound in InitDS, it won't take account the setting.

Regards,
Handy

The webcombo is bound to an ISDataSource, but I'm assigning the ID of the datasource in the InitializeDataSource event ... so I understand that in this case, it won't work, correct ? Is there any possible workarround ?

Hi Patrick,

Please let me clear one thing about this attribute. NonRetrievable  is only an attribute or a flag.
Those attribute does not do any process. In WebGrid, when bind to ISDS, this attribute only a flag.
All the process is converting a CustomObject into a datatable then bind into WebGrid.
During the converting, if this flag is on, the current properties would not be listed into datatable.
That's why after RetrieveStructure on WebGrid, the data which is flagged on, would not be listed.

WebCombo is the other things. WebCombo does not need this process. It can just accept CustomObject directly. That's why when you set that attribute, nothing happen. But once again, if you don't want it to be called, you must not set the value on that properties. If you set the value, of course the data would be populated. 

Regards,
Handy