You can add additional messages or message
components as sources or targets in your message map. To add a message or
message component to a source or target:
You can also add sources and targets
by dragging the resources from the Broker Development view in the Broker Application Development perspective onto
the source or target pane of your message map. Select resources under Messages
or Elements and Attributes or Types from your Message Definitions and drag
them onto the source or target pane. If you add a message to the message map,
Properties are also added. If you add an element, attribute or type to
the to the message map a global element for a submap is created. Your
message map must use either messages or global elements and not a combination
of both.
A Mapping node can
have only one source message, but can have several target messages. Therefore,
you cannot add a source message if one already exists.