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9.32 ModelChangeEvents ToC Previous Next

9.32.3 Views ToC Previous Next

A ModelChangeEvent is always generated in the context of a View, including the default View where the whole AddressSpace is considered. Therefore the only Notifiers which report the ModelChangeEvents are View Nodes and the Server Object representing the default View. Each action generating a ModelChangeEvent may lead to several Events since it may affect different Views. If, for example, a Node was deleted from the AddressSpace, and this Node was also contained in a View “A”, there would be one Event having the AddressSpace as context and another having the View “A” as context. If a Node would only be removed from View “A”, but still exists in the AddressSpace, it would generate only a ModelChangeEvent for View “A”.

If a Client does not want to receive duplicates of changes then it shall use the filter mechanisms of the Event subscription to filter only for the default View and suppress the ModelChangeEvents having other Views as the context.

When a ModelChangeEvent is issued on a View and the View supports the ViewVersion Property, then the ViewVersion shall be updated.

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