Interface DataTreeChangeService
- All Superinterfaces:
BindingService
- All Known Subinterfaces:
DataBroker
- All Known Implementing Classes:
BindingDOMDataBrokerAdapter
,DataBrokerFailuresImpl
,ForwardingDataBroker
,OSGiDataBroker
BindingService
which allows users to register for changes to a subtree.-
Method Summary
Modifier and TypeMethodDescription<T extends DataObject,
L extends DataTreeChangeListener<T>>
@NonNull ListenerRegistration<L>registerDataTreeChangeListener
(@NonNull DataTreeIdentifier<T> treeId, @NonNull L listener) Registers aDataTreeChangeListener
to receive notifications when data changes under a given path in the conceptual data tree.
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Method Details
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registerDataTreeChangeListener
<T extends DataObject,L extends DataTreeChangeListener<T>> @NonNull ListenerRegistration<L> registerDataTreeChangeListener(@NonNull DataTreeIdentifier<T> treeId, @NonNull L listener) Registers aDataTreeChangeListener
to receive notifications when data changes under a given path in the conceptual data tree.You are able to register for notifications for any node or subtree which can be represented using
DataTreeIdentifier
.You are able to register for data change notifications for a subtree or leaf even if it does not exist. You will receive notification once that node is created.
If there is any pre-existing data in the data tree for the path for which you are registering, you will receive an initial data change event, which will contain all pre-existing data, marked as created.
This method returns a
ListenerRegistration
object. To "unregister" your listener for changes call theListenerRegistration.close()
method on the returned object.You MUST explicitly unregister your listener when you no longer want to receive notifications. This is especially true in OSGi environments, where failure to do so during bundle shutdown can lead to stale listeners being still registered.
- Parameters:
treeId
- Data tree identifier of the subtree which should be watched for changes.listener
- Listener instance which is being registered- Returns:
- Listener registration object, which may be used to unregister
your listener using
ListenerRegistration.close()
to stop delivery of change events.
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