CloneObjectViewController.CustomCloneObject Event

Occurs before the default cloning process begins.

Namespace: DevExpress.ExpressApp.CloneObject

Assembly: DevExpress.ExpressApp.CloneObject.v18.2.dll

Declaration

C#

public event EventHandler<CustomCloneObjectEventArgs> CustomCloneObject

VB.NET

Public Event CustomCloneObject As EventHandler(Of CustomCloneObjectEventArgs)

Event Data

The CustomCloneObject event's data class is CustomCloneObjectEventArgs. The following properties provide information specific to this event:

Property	Description
ClonedObject	Represents the target object of the cloning process.
SourceObject	Gets the object to be cloned.
TargetObjectSpace	Specifies the Object Space of the target object.
TargetType	Gets the type of the target object.

The event data class exposes the following methods:

Method	Description
CreateDefaultTargetObjectSpace()	Returns an Object Space for the CustomCloneObjectEventArgs.ClonedObject.

Remarks

When this event is handled and the handler’s ClonedObject parameter is initialized, the object represented by this parameter becomes the target object of the cloning process. Otherwise, default cloning is performed.

Handle this event to implement custom cloning logic. Pass the custom cloned object via the handler’s ClonedObject parameter. Pass the target object’s Object Space via the TargetObjectSpace parameter.

To manually clone a source object, handle this event and assign a custom cloned object to the CustomCloneObjectEventArgs.ClonedObject parameter. If the event is not handled or the ClonedObject parameter is null (Nothing in VB), the default cloning is performed.

By default, the CustomCloneObjectEventArgs.TargetObjectSpace parameter refers to an IObjectSpace object. Initialize the TargetObjectSpace property to use custom Object Space type object to clone an object.

Note

When the handler’s ClonedObject parameter is passed, but the TargetObjectSpace parameter is null (Nothing in VB), an exception is raised.

You can implement a custom DevExpress.Persistent.Base.Cloner class descendant to customize the cloning process, and then call it’s CloneTo method in the CustomCloneObject event handler.

The following snippet illustrates how to override the Cloner.CopyMemberValue method to skip association proprerties when cloning.

C#

using DevExpress.ExpressApp.CloneObject;
using DevExpress.Xpo.Metadata;
using DevExpress.Xpo;
using DevExpress.Persistent.Base;
//...
public class CustomizeCloneObjectController : ObjectViewController {
    protected override void OnActivated() {
        base.OnActivated();
        var cloneObjectController = Frame.GetController<CloneObjectViewController>();
        if (cloneObjectController != null) {
            cloneObjectController.CustomCloneObject += cloneObjectController_CustomCloneObject;
        }
    }
    void cloneObjectController_CustomCloneObject(object sender, CustomCloneObjectEventArgs e) {
        var cloner = new MyCloner();
        e.TargetObjectSpace = e.CreateDefaultTargetObjectSpace();
        object objectFromTargetObjectSpace = e.TargetObjectSpace.GetObject(e.SourceObject);
        e.ClonedObject = cloner.CloneTo(objectFromTargetObjectSpace, e.TargetType);
    }
}
public class MyCloner : Cloner {
    public override void CopyMemberValue(
        XPMemberInfo memberInfo, IXPSimpleObject sourceObject, IXPSimpleObject targetObject) {
        if (!memberInfo.IsAssociation) {
            base.CopyMemberValue(memberInfo, sourceObject, targetObject);
        }
    }
}

VB.NET

Imports DevExpress.ExpressApp.CloneObject
Imports DevExpress.Xpo.Metadata
Imports DevExpress.Xpo
Imports DevExpress.Persistent.Base
'...
Public Class CustomizeCloneObjectController
    Inherits ObjectViewController

    Protected Overrides Sub OnActivated()
        MyBase.OnActivated()
        Dim cloneObjectController = Frame.GetController(Of CloneObjectViewController)()
        If cloneObjectController IsNot Nothing Then
            cloneObjectController.CustomCloneObject += cloneObjectController_CustomCloneObject
        End If
    End Sub
    Private Sub cloneObjectController_CustomCloneObject(ByVal sender As Object, ByVal e As CustomCloneObjectEventArgs)
        Dim cloner = New MyCloner()
        e.TargetObjectSpace = e.CreateDefaultTargetObjectSpace()
        Dim objectFromTargetObjectSpace As Object = e.TargetObjectSpace.GetObject(e.SourceObject)
        e.ClonedObject = cloner.CloneTo(objectFromTargetObjectSpace, e.TargetType)
    End Sub
End Class
Public Class MyCloner
    Inherits Cloner

    Public Overrides Sub CopyMemberValue(ByVal memberInfo As XPMemberInfo, ByVal sourceObject As IXPSimpleObject, ByVal targetObject As IXPSimpleObject)
        If Not memberInfo.IsAssociation Then
            MyBase.CopyMemberValue(memberInfo, sourceObject, targetObject)
        End If
    End Sub
End Class