The Collection Source used for the List Views created by Lookup Property Editors.
In XAF, by default, reference properties are displayed in a UI via Lookup Property Editors. To display a drop-down list of the possible property values, a Lookup Property Editor creates a List View. List Views of this kind use instances either of the CollectionSource class or of the LookupEditPropertyCollectionSource class as the data sources. The letter is used when the DataSourcePropertyAttribute is applied to the reference property. In all other scenarios, an instance of the CollectionSource class is used as a data source.
The LookupEditPropertyCollectionSource is also used as the data source by List Views invoked via the LinkUnlinkController.LinkAction to edit a collection property that has the DataSourcePropertyAttribute applied to it.
Compared to the PropertyCollectionSource, the LookupEditPropertyCollectionSource introduces the additional LookupEditPropertyCollectionSource.LookupMode property, whose value can be used to determine the kind of List View that uses the LookupEditPropertyCollectionSource. The LookupMode property may return one of the two LookupEditCollectionSourceMode enumeration's values:
LookupEditPropertyCollectionSource can only be created in client mode, because it is used for List Views that display a particular set of objects specified by a property (see DataSourcePropertyAttribute).