Reference Properties in Domain Components

• Mar 26, 2018
• 2 minutes to read

The example below illustrates how to implement Reference (Foreign Key, Complex Type) Properties in a Domain Component interface.

C#

// Displayed in a lookup control:
IReferencedObject LookupReferencedObject { get; set; }
// Displayed in a set of editors. Each editor represents an individual property of the referenced object:
[DevExpress.ExpressApp.DC.AggregatedAttribute, ExpandObjectMembers(ExpandObjectMembers.Always)]
IExpandPropertiesObject ExpandPropertiesObject { get; set; }
// Displayed in a Detail Property Editor that shows a referenced object's Detail View:
[DevExpress.ExpressApp.DC.AggregatedAttribute, EditorAlias(EditorAliases.DetailPropertyEditor)]
[ExpandObjectMembers(ExpandObjectMembers.Never)]
IEmbeddedDetailViewObject EmbeddedDetailViewObject { get; set; }
// Displayed in a button edit that invokes a referenced object's Detail View in a separate modal window:
[DevExpress.ExpressApp.DC.AggregatedAttribute, ExpandObjectMembers(ExpandObjectMembers.Never)]
IPopupDetailViewObject PopupDetailViewObject { get; set; }

VB.NET

' Displayed in a lookup control:
Property LookupReferencedObject() As IReferencedObject
' Displayed in a set of editors. Each editor represents an individual property of the referenced object:
<DevExpress.ExpressApp.DC.AggregatedAttribute, ExpandObjectMembers(ExpandObjectMembers.Always)>
Property ExpandPropertiesObject() As IExpandPropertiesObject
' Displayed in a Detail Property Editor that shows a referenced object's Detail View:
<DevExpress.ExpressApp.DC.AggregatedAttribute, EditorAlias(EditorAliases.DetailPropertyEditor), _
ExpandObjectMembers(ExpandObjectMembers.Never)>
Property EmbeddedDetailViewObject() As IEmbeddedDetailViewObject
' Displayed in a button edit that invokes a referenced object's Detail View in a separate modal window:
<DevExpress.ExpressApp.DC.AggregatedAttribute, ExpandObjectMembers(ExpandObjectMembers.Never)>
Property PopupDetailViewObject() As IPopupDetailViewObject

If you use Detail Property Editor for a reference property, or apply ExpandObjectMembers attribute to a reference property, it is required to initialize such a property in the when a new parent object is created. Otherwise, the reference property’s fields will be read-only. The initialization should be done in the overridden AfterConstruction method of the attached Domain Logic the following way:

C#

[DomainLogic(typeof(IReferenceProperties))]
public class IReferenceProperties_Logic {
    public void AfterConstruction(IReferenceProperties obj, IObjectSpace objectSpace) {
        obj.EmbeddedDetailViewObject = objectSpace.CreateObject<IEmbeddedDetailViewObject>();
    }
}

VB.NET

<DomainLogic(GetType(IReferenceProperties))> _
Public Class IReferenceProperties_Logic
    Public Sub AfterConstruction(ByVal obj As IReferenceProperties, ByVal objectSpace As IObjectSpace)
        obj.EmbeddedDetailViewObject = objectSpace.CreateObject(Of IEmbeddedDetailViewObject)()
    End Sub
End Class