Interface NodeSubscription
-
- All Superinterfaces:
QualifiedValueListener
- All Known Implementing Classes:
AbstractNodePropertyManager.ChangeTrackingNodeSubscription
public interface NodeSubscription extends QualifiedValueListener
Represents the connection between the tag subscription model and the tag execution model. This is provided to executing nodes in order to deliver values to all listeners. To that end, it extendsQualifiedValueListener
, and the node should callQualifiedValueListener.valueChanged(QualifiedValue)
when appropriate.The node can look at isLeased() as required, though leased state changes will be communicated through calling
Node.setLeased(boolean)
as well.Finally, if the node is being destroyed, it must communicate that to the subscription system by calling disconnectNode().
- Since:
- 8.0
-
-
Method Summary
All Methods Instance Methods Abstract Methods Modifier and Type Method Description void
disconnectNode()
Should be called by the Node when it is destroyed in order to let the subscription model know that the node is no longer present.boolean
isLeased()
Indicates that the node has at least one "heavy weight" listener.-
Methods inherited from interface com.inductiveautomation.ignition.common.tags.QualifiedValueListener
valueChanged
-
-
-
-
Method Detail
-
disconnectNode
void disconnectNode()
Should be called by the Node when it is destroyed in order to let the subscription model know that the node is no longer present.
-
isLeased
boolean isLeased()
Indicates that the node has at least one "heavy weight" listener.- Returns:
- true if the node should be executing in its "leased" state.
-
-