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org.apache.lenya.workflow.impl
Class History

java.lang.Object
  org.apache.lenya.workflow.impl.History

All Implemented Interfaces:

WorkflowListener

Direct Known Subclasses:

CMSHistory

public abstract class History
extends java.lang.Object
implements WorkflowListener

The history of a workflow instance contains a list of all versions of the instance. A version contains

• the state,
• the event that caused the transition (omitted in the first version).

Field Summary

static java.lang.String	DATE_ATTRIBUTE
static java.lang.String	EVENT_ATTRIBUTE
static java.lang.String	HISTORY_ELEMENT
static java.lang.String	NAME_ATTRIBUTE
static java.lang.String	STATE_ATTRIBUTE
static java.lang.String	VALUE_ATTRIBUTE
static java.lang.String	VARIABLE_ELEMENT
static java.lang.String	VERSION_ELEMENT
static java.lang.String	WORKFLOW_ATTRIBUTE

Constructor Summary

protected

History() Creates a new history object for a workflow instance.

Method Summary

protected org.w3c.dom.Element	createInitialVersionElement(NamespaceHelper helper, Situation situation, java.lang.String workflowId) Creates a new version element.
protected abstract WorkflowInstanceImpl	createInstance() Factory method to create a workflow instance object.
protected org.w3c.dom.Element	createVersionElement(NamespaceHelper helper, Situation situation) Creates a version element based on a situation.
protected org.w3c.dom.Element	createVersionElement(NamespaceHelper helper, StateImpl state, Situation situation, Event event) Creates a new version element.
void	delete() Deletes the history.
protected abstract java.io.File	getHistoryFile() Factory method to obtain the history file.
WorkflowInstanceImpl	getInstance() Restores the workflow, state and variables of a workflow instance from this history.
protected NamespaceHelper	getNamespaceHelper() Returns the namespace helper for the history file.
Version[]	getVersions() Returns the versions of this history.
protected java.lang.String	getWorkflowId() Returns the workflow ID for this history.
protected java.lang.String	getWorkflowId(NamespaceHelper helper) Returns the workflow ID for this history.
void	initialize(java.lang.String workflowId, Situation situation) Creates a new history object.
boolean	isInitialized() Returns if the history has been initialized.
protected void	move(java.io.File newFile) Moves this history to a new file.
protected void	restoreState(WorkflowInstanceImpl instance, NamespaceHelper helper) Restores the state of a workflow instance.
protected void	restoreVariables(WorkflowInstanceImpl instance, NamespaceHelper helper) Restores the state variables of a workflow instance.
protected Version	restoreVersion(NamespaceHelper helper, org.w3c.dom.Element element) Restores a version from an XML element.
protected void	saveVariables(NamespaceHelper helper) Saves the state variables as children of the document element.
void	setInstance(WorkflowInstanceImpl impl) Sets the workflow instance.
void	transitionFired(WorkflowInstance instance, Situation situation, Event event) Advances the workflow history when a tranistion was invoked.

Methods inherited from class java.lang.Object

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

Field Detail

WORKFLOW_ATTRIBUTE

public static final java.lang.String WORKFLOW_ATTRIBUTE

See Also:

Constant Field Values

HISTORY_ELEMENT

public static final java.lang.String HISTORY_ELEMENT

See Also:

Constant Field Values

VERSION_ELEMENT

public static final java.lang.String VERSION_ELEMENT

See Also:

Constant Field Values

STATE_ATTRIBUTE

public static final java.lang.String STATE_ATTRIBUTE

See Also:

Constant Field Values

EVENT_ATTRIBUTE

public static final java.lang.String EVENT_ATTRIBUTE

See Also:

Constant Field Values

VARIABLE_ELEMENT

public static final java.lang.String VARIABLE_ELEMENT

See Also:

Constant Field Values

NAME_ATTRIBUTE

public static final java.lang.String NAME_ATTRIBUTE

See Also:

Constant Field Values

VALUE_ATTRIBUTE

public static final java.lang.String VALUE_ATTRIBUTE

See Also:

Constant Field Values

DATE_ATTRIBUTE

public static final java.lang.String DATE_ATTRIBUTE

See Also:

Constant Field Values

Constructor Detail

History

protected History()

Creates a new history object for a workflow instance.

Method Detail

initialize

public void initialize(java.lang.String workflowId,
                       Situation situation)
                throws WorkflowException

Creates a new history object. A new history file is created and initialized.

Parameters:

workflowId - The workflow ID.

situation - The current situation.

Throws:

WorkflowException - when something went wrong.

getNamespaceHelper

protected NamespaceHelper getNamespaceHelper()
                                      throws WorkflowException

Returns the namespace helper for the history file.

Returns:

A namespace helper.

Throws:

WorkflowException - It the helper could not be obtained.

getWorkflowId

protected java.lang.String getWorkflowId()
                                  throws WorkflowException

Returns the workflow ID for this history.

Returns:

A string.

Throws:

WorkflowException - when something went wrong.

getWorkflowId

protected java.lang.String getWorkflowId(NamespaceHelper helper)
                                  throws WorkflowException

Returns the workflow ID for this history.

Parameters:

helper - The namespace helper for the history document.

Returns:

A string.

Throws:

WorkflowException - when something went wrong.

getInstance

public WorkflowInstanceImpl getInstance()
                                 throws WorkflowException

Restores the workflow, state and variables of a workflow instance from this history.

Returns:

The workflow instance to restore.

Throws:

WorkflowException - if something goes wrong.

isInitialized

public boolean isInitialized()

Returns if the history has been initialized.

Returns:

A boolean value.

getHistoryFile

protected abstract java.io.File getHistoryFile()

Factory method to obtain the history file.

Returns:

A file.

createInstance

protected abstract WorkflowInstanceImpl createInstance()
                                                throws WorkflowException

Factory method to create a workflow instance object.

Returns:

A workflow instance object.

Throws:

WorkflowException - if something goes wrong.

createInitialVersionElement

protected org.w3c.dom.Element createInitialVersionElement(NamespaceHelper helper,
                                                          Situation situation,
                                                          java.lang.String workflowId)
                                                   throws WorkflowException

Creates a new version element. This method is called after a tansition invocation.

Parameters:

helper - The namespace helper of the history document.

situation - The current situation.

workflowId - The workflow ID.

Returns:

An XML element.

Throws:

WorkflowException - when something went wrong.

createVersionElement

protected org.w3c.dom.Element createVersionElement(NamespaceHelper helper,
                                                   StateImpl state,
                                                   Situation situation,
                                                   Event event)

Creates a new version element. This method is called after a tansition invocation.

Parameters:

helper - The namespace helper of the history document.

state - The state of the new version.

situation - The current situation.

event - The event that was invoked.

Returns:

An XML element.

createVersionElement

protected org.w3c.dom.Element createVersionElement(NamespaceHelper helper,
                                                   Situation situation)

Creates a version element based on a situation.

Parameters:

helper - The namespace helper of the history document.

situation - The current situation.

Returns:

An XML element.

transitionFired

public void transitionFired(WorkflowInstance instance,
                            Situation situation,
                            Event event)
                     throws WorkflowException

Advances the workflow history when a tranistion was invoked.

Specified by:

transitionFired in interface WorkflowListener

Parameters:

instance - The workflow instance.

situation - The situation before the transition.

event - The invoked event.

Throws:

WorkflowException - when something went wrong.

setInstance

public void setInstance(WorkflowInstanceImpl impl)

Sets the workflow instance.

Parameters:

impl - A workflow instance implementation.

saveVariables

protected void saveVariables(NamespaceHelper helper)
                      throws WorkflowException

Saves the state variables as children of the document element.

Parameters:

helper - The helper that holds the document.

Throws:

WorkflowException - when something went wrong.

restoreVariables

protected void restoreVariables(WorkflowInstanceImpl instance,
                                NamespaceHelper helper)
                         throws WorkflowException

Restores the state variables of a workflow instance.

Parameters:

instance - The instance to restore.

helper - The helper that wraps the history document.

Throws:

WorkflowException - when something went wrong.

restoreState

protected void restoreState(WorkflowInstanceImpl instance,
                            NamespaceHelper helper)
                     throws WorkflowException

Restores the state of a workflow instance.

Parameters:

instance - The instance to restore.

helper - The helper that wraps the history document.

Throws:

WorkflowException - when something went wrong.

move

protected void move(java.io.File newFile)
             throws WorkflowException

Moves this history to a new file.

Parameters:

newFile - The new file.

Throws:

WorkflowException - when something went wrong.

restoreVersion

protected Version restoreVersion(NamespaceHelper helper,
                                 org.w3c.dom.Element element)
                          throws WorkflowException

Restores a version from an XML element.

Parameters:

helper - The namespace helper.

element - An XML element.

Returns:

A version.

Throws:

WorkflowException - when something went wrong.

getVersions

public Version[] getVersions()
                      throws WorkflowException

Returns the versions of this history.

Returns:

An array of versions.

Throws:

WorkflowException - when something went wrong.

delete

public void delete()
            throws WorkflowException

Deletes the history.

Throws:

WorkflowException - when something went wrong.