wt.graph
Class ObjectGraphCallback

java.lang.Object
  wt.visitor.CompositeVisitor
      wt.graph.ObjectGraphCallback

All Implemented Interfaces:

Serializable, Visitor

public class ObjectGraphCallback
extends CompositeVisitor
implements Serializable

Performs common pre/post-processing activities on each visited node as a callback. This could also be a customization point where application callbacks (visitors) are added to help satisfy a particular consumer's specific requirements.

For instance, if an application had additional requirements to censor information in the object graph, based on say specific access control permissions, then the application could add their custom visitor to the object graph's set visitor. Then when the object graph was next traversed, not only would all of the previously added visitors be employed, but additionally the newly added application visitor as well.

Supported API: true

Extendable: false

See Also:

Serialized Form

Method Summary

boolean	visit(Persistable fromNode, Link link, Persistable toNode, int level, boolean previouslyVisited) Visit a node.
boolean	visitLevel(Persistable fromNode, Vector links, Vector toNodes, int level) Vist nodes at this level.
boolean	visitLevel(Vector fromNodes, Vector links, Vector toNodes, int level) Vist nodes at this level.

Methods inherited from class wt.visitor.CompositeVisitor

addVisitor, removeVisitor

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

visit

public boolean visit(Persistable fromNode,
                     Link link,
                     Persistable toNode,
                     int level,
                     boolean previouslyVisited)
              throws WTException

Visit a node. If false is returned, then the node will not be traversed.

Supported API: true

Specified by:

visit in interface Visitor

Overrides:

visit in class CompositeVisitor

Parameters:

fromNode -

link -

toNode -

level -

previouslyVisited -

Returns:

boolean

Throws:

WTException

visitLevel

public boolean visitLevel(Persistable fromNode,
                          Vector links,
                          Vector toNodes,
                          int level)
                   throws WTException

Vist nodes at this level. If false is returned, then none of the nodes on this level will be traversed.

Supported API: true

Specified by:

visitLevel in interface Visitor

Overrides:

visitLevel in class CompositeVisitor

Parameters:

fromNode -

links -

toNodes -

level -

Returns:

boolean

Throws:

WTException

visitLevel

public boolean visitLevel(Vector fromNodes,
                          Vector links,
                          Vector toNodes,
                          int level)
                   throws WTException

Vist nodes at this level. If false is returned, then none of the nodes on this level will be traversed.

Supported API: true

Specified by:

visitLevel in interface Visitor

Overrides:

visitLevel in class CompositeVisitor

Parameters:

fromNodes -

links -

toNodes -

level -

Returns:

boolean

Throws:

WTException