org.azyva.dragom.model

Interface MutableNode

All Superinterfaces:

Node

All Known Subinterfaces:

MutableClassificationNode, MutableModule

public interface MutableNode
extends Node

Extension of Node that allows changing the configuration data.

Methods in this interface are similar to those in MutableNodeConfig. This is normal since what is mutable is the configuration data, which MutableNode simply exposes. Note however that only NodeConfigTransferObject is exposed, and not MutableNodeConfig itself. This could allow a MutableNode implementation to not be based on MutableNodeConfig, although the inverse is generally the case.

OptimisticLockHandle is used to handle optimistic locking. Support for optimistic locking is not required. But if not supported, implementations must respect the contract imposed by OptimisticLockHandle and the methods that use it, doing as if the lock was always valid.

Optimistic lock management is generally delegated to the similar methods in MutableNodeConfig on which a Node is generally based.

Author:

David Raymond

See Also:

MutableModel

Method Summary

Modifier and Type	Method and Description
OptimisticLockHandle	createOptimisticLockHandle(boolean indLock) Creates an OptimisticLockHandle.
void	delete() Deletes the MutableNode.
NodeConfigTransferObject	getNodeConfigTransferObject(OptimisticLockHandle optimisticLockHandle) Returns the NodeConfigTransferObject.
boolean	isDeleted() Indicates if the MutableNode has been deleted.
boolean	isNew() See MutableNodeConfig.isNew().
boolean	isOptimisticLockValid(OptimisticLockHandle optimisticLockHandle) Verifies if the lock held by the an OptimisticLockHandle is valid, meaning that its state corresponds to the state of the data it represents.
void	setNodeConfigTransferObject(NodeConfigTransferObject nodeConfigTransferObject, OptimisticLockHandle optimisticLockHandle) Sets the NodeConfigTransferObject.

Methods inherited from interface org.azyva.dragom.model.Node

getClassificationNodeParent, getListPluginId, getModel, getName, getNodePath, getNodePlugin, getNodeType, getProperty, isCreatedDynamically, isNodePluginExists, raiseNodeEvent, registerListener

Method Detail

isNew

boolean isNew()

See MutableNodeConfig.isNew().

Returns:

Indicates that the MutableNode has just been created and that setNodeConfigTransferObject(org.azyva.dragom.model.config.NodeConfigTransferObject, org.azyva.dragom.model.config.OptimisticLockHandle) has not been called yet.

createOptimisticLockHandle

OptimisticLockHandle createOptimisticLockHandle(boolean indLock)

Creates an OptimisticLockHandle.

See MutableNodeConfig.createOptimisticLockHandle(boolean).

Parameters:

indLock - Indicates if the OptimisticLockHandle must be initially locked.

Returns:

OptimisticLockHandle.

isOptimisticLockValid

boolean isOptimisticLockValid(OptimisticLockHandle optimisticLockHandle)

Verifies if the lock held by the an OptimisticLockHandle is valid, meaning that its state corresponds to the state of the data it represents.

See MutableNodeConfig.isOptimisticLockValid(org.azyva.dragom.model.config.OptimisticLockHandle).

Parameters:

optimisticLockHandle - OptimisticLockHandle.

Returns:

Indicates if the lock is valid.

getNodeConfigTransferObject

NodeConfigTransferObject getNodeConfigTransferObject(OptimisticLockHandle optimisticLockHandle)
                                              throws OptimisticLockException

Returns the NodeConfigTransferObject.

See MutableNodeConfig.getNodeConfigTransferObject(org.azyva.dragom.model.config.OptimisticLockHandle).

Parameters:

optimisticLockHandle - OptimisticLockHandle. Can be null.

Returns:

NodeConfigTransferObject.

Throws:

OptimisticLockException - This is a RuntimeException that may be of interest to the caller.

setNodeConfigTransferObject

void setNodeConfigTransferObject(NodeConfigTransferObject nodeConfigTransferObject,
                                 OptimisticLockHandle optimisticLockHandle)
                          throws OptimisticLockException,
                                 DuplicateNodeException

Sets the NodeConfigTransferObject.

See MutableNodeConfig.setNodeConfigTransferObject(org.azyva.dragom.model.config.NodeConfigTransferObject, org.azyva.dragom.model.config.OptimisticLockHandle).

Parameters:

nodeConfigTransferObject - NodeConfigTransferObject.

optimisticLockHandle - OptimisticLockHandle. Can be null.

Throws:

OptimisticLockException - This is a RuntimeException that may be of interest to the caller.

DuplicateNodeException - This is a RuntimeException that may be of interest to the caller.

delete

void delete()

Deletes the MutableNode.

See MutableNodeConfig.delete().

isDeleted

boolean isDeleted()

Indicates if the MutableNode has been deleted.

A MutableNode can be deleted only if delete() is called. Specifically an implementation must not rely on removing MutableNode's from internal caches to force their recreation when changes to configuration data could affect their state. Instead, the implementation must ensure that created MutableNode's remain valid, but can reset their internal state if required.

delete could be called, followed by the recreation of the MutableNode. But delete is an interface method and is intended to be called by an external caller, not by the implementation itself.

A special case exists. If the MutableNode has been created dynamically using NodeBuilder and is converted into one based on MutableNodeConfig, the former can be deleted. This is getting close to a hack since this case is hard to handle cleanly. In general, it is expected that an application allowing to manage persistent MutableConfig data will not include tasks that would cause the dynamic creation of MutableNode's, so this case would not occur. And tasks which can benefit from the dynamic creation of Node's are expected to be tools that consume the Config data to perform jobs on reference graphs and in turn, these do not modify the Config, so this case would not occur either.

Returns:

Indicates if the MutableNode has been deleted.