CompositeObjectSpace.AdditionalObjectSpaces Property

Gets the list of Object Spaces used to handle objects that do not belong to the current Object Space. We recommend that you call the PopulateAdditionalObjectSpaces(XafApplication) method to populate this collection automatically.

Namespace: DevExpress.ExpressApp

Assembly: DevExpress.ExpressApp.v20.2.dll

NuGet Package: DevExpress.ExpressApp

Declaration

C#

public IList<IObjectSpace> AdditionalObjectSpaces { get; }

VB.NET

Public ReadOnly Property AdditionalObjectSpaces As IList(Of IObjectSpace)

Property Value

Type	Description
IList<IObjectSpace>	An IList<T> collection of Object Spaces used to handle objects that do not belong to the current Object Space.

Exceptions

Type	Description
InvalidOperationException	Cannot add the Object Space to the CompositeObjectSpace.AdditionalObjectSpaces collection because another Object Space for the same object types already exists.

Remarks

You can use one of the following ways to fill this collection.

Automatically: Use PopulateAdditionalObjectSpaces (Recommended technique)

1. Handle the XafApplication.ObjectSpaceCreated event in a module or Controller.
2. In the event handler, call the PopulateAdditionalObjectSpaces(XafApplication) method to populate the AdditionalObjectSpaces collection with all necessary Object Spaces.

The following example demonstrates how to do this in a platform-agnostic module (MySolution.Module/Module.cs(vb)):

C#

using DevExpress.ExpressApp;
//...
public class MySolutionModule : ModuleBase {
    //...
    public override void Setup(XafApplication application) {
        base.Setup(application);
        application.ObjectSpaceCreated += Application_ObjectSpaceCreated;
    }
    private void Application_ObjectSpaceCreated(object sender, ObjectSpaceCreatedEventArgs e) {
        CompositeObjectSpace compositeObjectSpace = e.ObjectSpace as CompositeObjectSpace;
        if (compositeObjectSpace != null) {
            if (!(compositeObjectSpace.Owner is CompositeObjectSpace)) {
                compositeObjectSpace.PopulateAdditionalObjectSpaces((XafApplication)sender);
            }
        }
    }
}

VB.NET

Imports DevExpress.ExpressApp
'...
Public Class MySolutionModule
    Inherits ModuleBase

    '...
    Public Overrides Sub Setup(ByVal application As XafApplication)
        MyBase.Setup(application)
        AddHandler application.ObjectSpaceCreated, AddressOf Application_ObjectSpaceCreated
    End Sub
    Private Sub Application_ObjectSpaceCreated(ByVal sender As Object, ByVal e As ObjectSpaceCreatedEventArgs)
        Dim compositeObjectSpace As CompositeObjectSpace = TryCast(e.ObjectSpace, CompositeObjectSpace)
        If compositeObjectSpace IsNot Nothing Then
            If Not (TypeOf compositeObjectSpace.Owner Is CompositeObjectSpace) Then
                compositeObjectSpace.PopulateAdditionalObjectSpaces(DirectCast(sender, XafApplication))
            End If
        End If
    End Sub
End Class

Manually: Create Object Spaces and Add Them to the Collection

If you need to create an additional Object Space manually, follow the steps below:

1. Handle the XafApplication.ObjectSpaceCreated event in a module or Controller.
2. In the event handler, access NonPersistentObjectSpace and use its IsKnownType(Type, Boolean) method to ensure that the AdditionalObjectSpaces collection does not already include a compatible Object Space.

The following example demonstrates how to do this in a platform-agnostic module (MySolution.Module/Module.cs(vb)):

C#

using DevExpress.ExpressApp;
//...
public class MySolutionModule : ModuleBase {
    //...
    public override void Setup(XafApplication application) {
        base.Setup(application);
        application.ObjectSpaceCreated += Application_ObjectSpaceCreated;
    }
    private void Application_ObjectSpaceCreated(object s, ObjectSpaceCreatedEventArgs e) {
        var nonPersistentObjectSpace = e.ObjectSpace as NonPersistentObjectSpace;
        if (nonPersistentObjectSpace != null) {
            if (!nonPersistentObjectSpace.IsKnownType(typeof(Person), true)) {
                IObjectSpace additionalObjectSpace = Application.CreateObjectSpace(typeof(Person));
                // customize the created additional Object Space
                nonPersistentObjectSpace.AdditionalObjectSpaces.Add(additionalObjectSpace);
                nonPersistentObjectSpace.Disposed += (s2, e2) => {
                    additionalObjectSpace.Dispose();
                };
            }
        }
    }
}

VB.NET

Imports DevExpress.ExpressApp
'...
Public Class MySolutionModule
    Inherits ModuleBase
    '...
    Public Overrides Sub Setup(ByVal application As XafApplication)
        MyBase.Setup(application)
        AddHandler application.ObjectSpaceCreated, AddressOf Application_ObjectSpaceCreated
    End Sub
    Private Sub Application_ObjectSpaceCreated(ByVal s As Object, ByVal e As ObjectSpaceCreatedEventArgs)
        Dim nonPersistentObjectSpace As NonPersistentObjectSpace = TryCast(e.ObjectSpace, NonPersistentObjectSpace)
        If nonPersistentObjectSpace IsNot Nothing Then
            If Not nonPersistentObjectSpace.IsKnownType(GetType(Person), True) Then
                Dim additionalObjectSpace As IObjectSpace = Application.CreateObjectSpace(GetType(Person))
                ' customize the created additional Object Space
                nonPersistentObjectSpace.AdditionalObjectSpaces.Add(additionalObjectSpace)
                AddHandler nonPersistentObjectSpace.Disposed, Sub(s2, e2)
                    additionalObjectSpace.Dispose()
                End Sub
            End If
        End If
    End Sub
End Class