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Notification Service

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This content is no longer actively maintained. It is provided as is, for anyone who may still be using these technologies, with no warranties or claims of accuracy with regard to the most recent product version or service release.

While Web Parts can be coded to communicate with one another directly by calling functions within the content of specific Web Parts, this is not a good practice. For example, if a particular Web Part is not on the dashboard or if a different version of it is present, the intended interaction might not take place. The Digital Dashboard Services Component (DDSC) solves these problems by acting as an intermediary between the various Web Parts on a dashboard.

The Web Part notification service provides a standard multicast event mechanism for Web Parts and hides the complexity of the underlying event mechanisms of the Web browser (DHTML events).

Through the Notification service, Web Parts can indicate interest in an event, thus providing a handle to a function that will be called when the event runs. Note that system and custom events are handled in exactly the same way.

All of the notification service methods are on the DDSC object.

Methods

RegisterForEvent(NamespaceURN, EventName, Function);
RaiseEvent (NamespaceURN, EventName, [optional] EventObject);

Parameters

  • NamespaceURN
    The unique namespace that describes the context for the event.
  • EventName
    The name of the event for which the Web Part is registering.
  • Function
    The function that should be called when the event occurs.
  • EventObject
    A variant type that contains additional data passed to the functions registered for this event.
  • S_OK, E_FAIL, or E_INVALIDARG
    Return values used for error handling.

See Also

Digital Dashboard Services Component | System Notifications (Notification Service) | Notification Service Example | Part Discovery Service | Session State Management Service | State Management Service | Item Retrieval Service