Handling MAPI Forms

A MAPI form is a viewer for a message of a particular class. Clients that allow their users to work with messages belonging to a variety of message classes must be written to handle a variety of MAPI forms. To handle multiple forms, clients implement a component known as a form viewer which contains three objects:

• Message site object, which supports the IMAPIMessageSite : IUnknown interface
• View advise sink, which supports the IMAPIViewAdviseSink : IUnknown interface
• View context object, which supports the IMAPIViewContext : IUnknown interface

Each of these objects is used by a component called the form server which implements each form, handling its storage and the notifications generated by clients handling the view. One other component, the form library provider, implements a form manager. The form manager administers the form libraries, which store form server executable files. This administration includes loading the appropriate form server and handling the initial communication between the server and the client.

The following diagram shows the relationship between a client and the other parts of the MAPI form architecture:

If your client plans to handle MAPI forms, you will use the form manager's IMAPIFormMgr interface to perform five basic tasks:

• Launch the appropriate MAPI form server when a message is opened or composed.
• Display form servers' icons in the contents tables of folders.
• Send and receive form notifications. See Sending and Receiving Form Notifications.
• Allow users to install or remove form servers from form libraries. See Maintaining a Form Library.
• Allow users to associate form servers with particular folders.

To access the form manager, call the MAPIOpenFormMgr function once during initialization.

For more information about MAPI forms, see Forms and Developing MAPI Form Servers.