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Wednesday, March 29, 2017

Improving UX with Grid List Editors by disabling ALL unsupported operations for non-persistent columns in server modes (XAF v16.2.6) - YOUR FEEDBACK IS NEEDED!

In server modes, grid controls perform operations like sorting, grouping, filtering, etc. on the data store side to guarantee the best performance. Thus, columns bound to non-persistent properties (their values exist only in the client memory at runtime) cannot be used for such server-based operations and can cause exceptions (learn more...). Some of them can be detected only in the end application after navigating to a problematic grid at runtime.

With XAF 16.2.6, to prevent these situations, we have improved column creation logic in our Grid List Editors for Windows and the Web. In particular, we have disabled all server-based operations (sorting, filtering, grouping) for non-persistent properties in the ASP.NET WebForms ASPxGridListEditor and WinForms GridListEditor when DataAccessMode = Server or InstantFeedback. 

Technically, it means the following:
    1) The grid's Find Panel does not take non-persistent properties into account.
    2) The grid's Filter Editor does not display non-persistent properties in the properties tree.
    3) The grid's Auto Filter Row feature is not available for non-persistent columns.
    4) Grid column headers for non-persistent columns do not allow end-users to filter, sort, group.

See this video recorded from the WinForms version of our MainDemo:

Take special note that in XPO, calculated non-persistent properties defined using PersistentAliasAttribute or CalculatedAttribute can still be used without problems for server-based operations as previously. The only PersistentAlias attribute scenario, which may still not lead to disabled server-side operations, is when you have an aliased reference property and a grid column with a complex property path like:
Such properties will be treated as regular non-persistent properties for now or you can disable our improvement using the feature toggle below.
For EF, calculated properties defined using CalculatedAttribute are still unsupported and treated as regular non-persistent properties mentioned above.

I do not need this behavior. How do I disable it?
With v16.2.7 (or, after installing this hot fix), you can set the PreventServerSideOperationsForNonPersistentMembers property of the DevExpress.ExpressApp.Editors > ColumnsListEditor  class to False in the overridden OnActivated method of a custom ViewController for a required ListView. Refer to the following example:

using DevExpress.ExpressApp; using DevExpress.ExpressApp.Editors; namespace MainDemo.Module.Controllers { public class S31714_FeatureToggle : ViewController<ListView> { protected override void OnActivated() { base.OnActivated(); ColumnsListEditor columnsListEditor = View.Editor as ColumnsListEditor; if(columnsListEditor != null) { columnsListEditor.PreventServerSideOperationsForNonPersistentMembers = false; } } } }
Imports DevExpress.ExpressApp Imports DevExpress.ExpressApp.Editors Namespace MainDemo.Module.Controllers Public Class S31714_FeatureToggle Inherits ViewController(Of ListView) Protected Overrides Sub OnActivated() MyBase.OnActivated() Dim columnsListEditor As ColumnsListEditor = TryCast(View.Editor, ColumnsListEditor) If columnsListEditor IsNot Nothing Then columnsListEditor.PreventServerSideOperationsForNonPersistentMembers = False End If End Sub End Class End Namespace


  1. Hi Dennis,

    what for is the feedback needed? This is a really great feature (even if you use XPO).

  2. wonder what is new here dennis - these things already worked long before - or do i miss something?

    3) The grid's Auto Filter Row feature is not available for non-persistent columns.
    4) Grid column headers for non-persistent columns do not allow end-users to filter, sort, group.

    1. Hello Martin,
      The features that you described were working only when XPServerCollectionSource was used as a grid control data source.

  3. Excellent!!!. Finally, it is a part of XAF. So far, we had to solve their own program.

  4. @Noxe: since 16.1 some parts didnt throw exceptions anymore (filtering) but grouping for example made the grid empty. but it wasn't preventing the user from making a mistake, ending in an inconnsistent ui state (where is my data)

    1. well ok - interessting, since i cannot group/filter/sort nonpersistent properties since ever - thats why i was asking :)

  5. Hi Dennis

    I think there is an issue with this when trying to compose Collection.Count() filters/criteria. I'll raise a SC issue.


    1. Thanks for your feedback, Chris. Have you installed the hot fix build?