org.speakright.core.flows
Class BranchFlow

java.lang.Object
  org.speakright.core.FlowBase
      org.speakright.core.flows.BranchFlow

All Implemented Interfaces:

java.io.Serializable, IFlow

public abstract class BranchFlow
extends FlowBase

BranchFlow provides branching of the callflow based on an application-defined condition. Derived classes override the branch method to supply the branching logic. Sub-flows can jump back to the branch flow later by 'throwing' a GotoBranchEvent.

Branch flows can loop forever if m_loopForever is set in the constructor. That is, when the sub-flows end the branch flow executes again.

Author:

Ian Rae

See Also:

Serialized Form

Nested Class Summary

static class

BranchFlow.GotoBranchEvent An event class used to jump back from a sub-flow to a branch flow.

Field Summary

protected boolean

m_loopForever

Constructor Summary

BranchFlow()

Method Summary

protected abstract IFlow	branch() Derived classes MUST override this and return a flow object to execute.
IFlow	getFirst(IFlowContext context) Do the branching, as determined by branch()
IFlow	getNext(IFlow current, SRResults results) If m_loopForever set then return this, else null.
IFlow	onCatch(IFlow current, SRResults results, java.lang.String eventName, ThrowEvent event) Catch a GotoBranchEvent that is targeted at this object, that is, the event's m_branchName matches our name.
protected abstract void	onCatchGotoBranchEvent(BranchFlow.GotoBranchEvent ev) Process the caught GotoBranchEvent.

Methods inherited from class org.speakright.core.FlowBase

createRenderer, execute, executionCount, fixupGrammar, fixupPrompt, getSubFlowAfter, log, logError, name, onBegin, onComplete, onDisconnect, onEnd, onNoInput, onPlatformError, onTransferFailed, onValidateFailed, promptGroup, setExecutionCount, setName, setPromptGroup, shouldExecute, validateInput

Methods inherited from class java.lang.Object

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

Field Detail

m_loopForever

protected boolean m_loopForever

Constructor Detail

BranchFlow

public BranchFlow()

Method Detail

getFirst

public IFlow getFirst(IFlowContext context)

Do the branching, as determined by branch()

Specified by:

getFirst in interface IFlow

Overrides:

getFirst in class FlowBase

Returns:

an IFlow object to be executed.

branch

protected abstract IFlow branch()

Derived classes MUST override this and return a flow object to execute.

Returns:

the flow object to execute. Cannot return null.

getNext

public IFlow getNext(IFlow current,
                     SRResults results)

If m_loopForever set then return this, else null.

Specified by:

getNext in interface IFlow

Overrides:

getNext in class FlowBase

Parameters:

current - the currently executing flow object. More precisely, current is the flow object that this object most recently returned from getFirst or getNext.

results - the results of current's execution by the speech platform. Results contains user input and/or events such as disconnect or platform-error.

Returns:

the next flow to run, or null which means this flow object is finished.

onCatch

public IFlow onCatch(IFlow current,
                     SRResults results,
                     java.lang.String eventName,
                     ThrowEvent event)

Catch a GotoBranchEvent that is targeted at this object, that is, the event's m_branchName matches our name. If we catch the event then onCatchGotoBranchEvent is invoked.

Specified by:

onCatch in interface IFlow

Overrides:

onCatch in class FlowBase

Parameters:

current - the currently executing flow object.

results - the results of current's execution.

eventName - name of the event. most event handling can be done using just the name.

event - event object. advanced event handling may require the actual event object

Returns:

the next flow to run, or null which means this flow object does not handle this event.

onCatchGotoBranchEvent

protected abstract void onCatchGotoBranchEvent(BranchFlow.GotoBranchEvent ev)

Process the caught GotoBranchEvent. The event's m_action usually contains data that is used to adjust the condition used by branch(). This lets the sub-flow that threw the event to control which branch is taken.

Parameters:

ev - the caught event.