org.apache.tapestry5.internal.services
Class AbstractSessionPersistentFieldStrategy

java.lang.Object
  org.apache.tapestry5.internal.services.AbstractSessionPersistentFieldStrategy

All Implemented Interfaces:

PersistentFieldStrategy

Direct Known Subclasses:

EntityPersistentFieldStrategy, EntityPersistentFieldStrategy, FlashPersistentFieldStrategy, SessionPersistentFieldStrategy

public abstract class AbstractSessionPersistentFieldStrategy
extends Object
implements PersistentFieldStrategy

Base class for strategies that store their values as keys in the session. Implements a uniform format for the keys, based on a prefix to identify the particular strategy.

Constructor Summary

protected

AbstractSessionPersistentFieldStrategy(String prefix, Request request)

Method Summary

protected Object	convertApplicationValueToPersisted(Object newValue) Hook that allows a value to be converted as it is written to the session.
protected Object	convertPersistedToApplicationValue(Object persistedValue) Converts a persisted value stored in the session back into an application value.
protected void	didReadChange(Session session, String attributeName) Called after each key is read by gatherFieldChanges(String).
void	discardChanges(String pageName) Discards any saved changes for the name page.
Collection<PersistentFieldChange>	gatherFieldChanges(String pageName) Finds all persistent changes previously stored for the named page (for the current active session or client).
void	postChange(String pageName, String componentId, String fieldName, Object newValue) Posts a change of a persistent property.

Methods inherited from class java.lang.Object

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

Constructor Detail

AbstractSessionPersistentFieldStrategy

protected AbstractSessionPersistentFieldStrategy(String prefix,
                                                 Request request)

Method Detail

gatherFieldChanges

public final Collection<PersistentFieldChange> gatherFieldChanges(String pageName)

Description copied from interface: PersistentFieldStrategy

Finds all persistent changes previously stored for the named page (for the current active session or client).

Specified by:

gatherFieldChanges in interface PersistentFieldStrategy

discardChanges

public void discardChanges(String pageName)

Description copied from interface: PersistentFieldStrategy

Discards any saved changes for the name page. There is no expectation that data already gathered from the strategy and persumably dumped into component instance fields will be affected, but future field access (within this request or a later one) will show no data for the indicated page.

Specified by:

discardChanges in interface PersistentFieldStrategy

Parameters:

pageName - logical name of page whose field persistent data should be discarded

didReadChange

protected void didReadChange(Session session,
                             String attributeName)

Called after each key is read by gatherFieldChanges(String). This implementation does nothing, subclasses may override.

Parameters:

session - the session from which a value was just read

attributeName - the name of the attribute used to read a value

postChange

public final void postChange(String pageName,
                             String componentId,
                             String fieldName,
                             Object newValue)

Description copied from interface: PersistentFieldStrategy

Posts a change of a persistent property.

Specified by:

postChange in interface PersistentFieldStrategy

Parameters:

pageName - the name of the page containing the component

componentId - the nested id path of the component (or null for the page's root component)

fieldName - the name of the field whose persistent value has changed

newValue - the new value for the field, possibly null

convertApplicationValueToPersisted

protected Object convertApplicationValueToPersisted(Object newValue)

Hook that allows a value to be converted as it is written to the session. Passed the new value provided by the application, returns the object to be stored in the session. This implementation simply returns the provided value.

Parameters:

newValue - non-null value

Returns:

persisted value

See Also:

convertPersistedToApplicationValue(Object)

convertPersistedToApplicationValue

protected Object convertPersistedToApplicationValue(Object persistedValue)

Converts a persisted value stored in the session back into an application value. This implementation returns the persisted value as is.

Parameters:

persistedValue - non-null persisted value

Returns:

application value

See Also:

convertPersistedToApplicationValue(Object)