Summary

The presentation layer of the three-tier application architecture is responsible for displaying data from your business objects and data objects to users and retrieving data from those users. The Windows DNA architecture supports a wide range of presentation layer architectures, from native Win32 applications to pure HTML Web-based applications. In all cases, the presentation layer applications use COM to access services from business layer components.

Although it is possible that the type of presentation layer application is defined as part of the application requirements, the architecture you select for a presentation layer application depends primarily on how the application will be deployed. Business objects can be accessed from user machines only if the user machines support COM and are configured to allow remote objects to be used. If business objects cannot be accessed directly from user machines, an ASP-based application architecture can be used. If business objects can be used from user machines, you might be able to use RDS, data-binding, or client-side scripting in your presentation layer implementation. The exact combination of technologies available to you will depend on the capabilities of the operating systems and Web browsers you must support.