com.sptci.echo2.binding
Class JDOModelUpdater<V,M extends JDOObject>

java.lang.Object
  com.sptci.echo2.binding.Updater<V,M>
      com.sptci.echo2.binding.ModelUpdater<V,M>
          com.sptci.echo2.binding.JDOModelUpdater<V,M>

Type Parameters:

V - The class name of the view component from which data is read.

M - The class name of the model object that is to be updated.

public class JDOModelUpdater<V,M extends JDOObject>
extends ModelUpdater<V,M>

An updater used to update JavaBean objects from their associated UI containers. Adds JDO specific actions such as making modifications within the bounds of a transaction.

The following shows sample use of this updater:

   import com.sptci.echo2.binding.JDOModelUpdater;

     ...
     // If persisting new instances to data store
     Bean bean = new Bean();
     bean.setName( "name" );
     bean.setDescription( "my name" );
     View view = new View( bean );
     // bind view from model and let user interact
     JDOModelUpdater updater = new JDOModeUpdater( view, bean );
     updater.update();

     ...
     // If updating persistent instances.
     Bean bean = BeanFactory.fetch( "name", pm );
     View view = new View( bean );
     // bind view from model and let user interact
     JDOModelUpdater updater = new JDOModelUpdater( view, bean );
     updater.update();
 

Copyright 2006 Sans Pareil Technologies, Inc.

Version:

$Id: JDOModelUpdater.java 4553 2008-12-24 10:34:16Z rakesh $

Author:

Rakesh Vidyadharan 2006-02-08

Field Summary

protected boolean	active A flag used to indicate whether a transaction is active or not with the pm.
protected NonTransactionalJDOApplication	app The global application instance for the user session.

Fields inherited from class com.sptci.echo2.binding.Updater

bean, logger, view

Constructor Summary

JDOModelUpdater(V view, M bean)
Create a new instance with the specified UI container and java bean.

Method Summary

protected void	begin() Initialise pm and start a transaction if necessary.
protected void	commit() Commit an existing trasaction associated with the pm if appropriate.
protected Object	getRepository() Fetch the repository instance to use to manage Updater.bean.
protected void	persist() Persist the Updater.bean to the data store.
protected void	rollback() Rollback the current transaction in case errors were encountered while interacting with the data store.
void	update() Over-ridden to conduct the updates with the bounds of a transaction as mandated by JDO.

Methods inherited from class com.sptci.echo2.binding.ModelUpdater

getFieldName, processCollection, updateField

Methods inherited from class com.sptci.echo2.binding.Updater

beanValues, getBean, getView, setBean, setView, viewValues

Methods inherited from class java.lang.Object

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

Field Detail

app

protected final NonTransactionalJDOApplication app

The global application instance for the user session.

active

protected boolean active

A flag used to indicate whether a transaction is active or not with the pm.

Constructor Detail

JDOModelUpdater

public JDOModelUpdater(V view,
                       M bean)

Create a new instance with the specified UI container and java bean.

Parameters:

view - The Updater.view to use.

bean - The Updater.bean to use.

Method Detail

update

public void update()

Over-ridden to conduct the updates with the bounds of a transaction as mandated by JDO. Starts a new transaction is necessary and delegates processing to the super-class method implementation. This method is usually used for persistent bean instances.

Overrides:

update in class ModelUpdater<V,M extends JDOObject>

Throws:

BindingException - If errors are encountered while accessing or setting the fields.

See Also:

begin(), ModelUpdater.update(), persist()

begin

protected void begin()

Initialise pm and start a transaction if necessary.

persist

protected void persist()
                throws BindingException

Persist the Updater.bean to the data store. Invokes the save method on an associated repository class for Updater.bean or directly on pm.

Throws:

BindingException - If errors are encountered while introspecting the repository.

See Also:

getRepository()

commit

protected void commit()

Commit an existing trasaction associated with the pm if appropriate.

rollback

protected void rollback()

Rollback the current transaction in case errors were encountered while interacting with the data store.

getRepository

protected Object getRepository()
                        throws ClassNotFoundException,
                               Throwable

Fetch the repository instance to use to manage Updater.bean.

Returns:

The repository instance if a standard instance exists.

Throws:

ClassNotFoundException - If the repository does not exist

Throwable - If other reflection errors are encountered.