Types Info Subsystem

May 27, 2025
2 minutes to read

The majority of the Application Model is generated based on the business classes used in an XAF application. To generate the Application Model, business class metadata is required. In XAF , this metadata is supplied by the types info subsystem, which is a set of classes and interfaces specifically designed to supply business class metadata.

The types info subsystem is presented by the static XafTypesInfo class, declared in the DevExpress.ExpressApp namespace, and the following interfaces.

Interface	Description
IBaseInfo	The base interface that supplies metadata on business classes and their members.
IMemberInfo	Supplies metadata on a member of a business class.
ITypeInfo	Supplies metadata on a business class.
ITypesInfo	Supplies metadata on business classes used by an XAF application.
IAssemblyInfo	Supplies metadata on an assembly used by an XAF application.

You do not need to implement these interfaces in most cases. These interfaces are implemented by a number of XAF system classes that can be accessed from different parts of your application. All of the mentioned interfaces are interlinked. For instance, if you have an ITypesInfo object, you can get information on any business class and its members, or the assembly in which it is declared. If you have an IMemberInfo object describing a property, you can get metadata on the assembly in which the property’s owner type is declared.

To learn more about the Types Info Subsystem , refer to the following topics.