Re: Capturing DataContextEvent or GraphEvent

From: Andrus Adamchik (andru..bjectstyle.org)
Date: Tue Oct 31 2006 - 21:00:17 EST


Yeah, using internal event mechanism in the application can be
confusing. Been there myself, so now I am advertising the
(unreleased) 3.0 callbacks as a better substitute :-)

Andrus

On Oct 31, 2006, at 11:10 AM, edward pedersson wrote:
> Found the problem. have to register a GraphEvent with the
> DataChannel to
> capture DataContext rollbacks but you can register
> DataContextEvent's with
> the DataContext to capture commits and willCommit. A little bit
> confusing...
>
> EventManager eventManager = this.getDataContext().getEventManager();
>
> //this never happens and not sure why
> //gets registered but i believe will only fire if there is an
> exception in a
> // commit and the transaction is rolledback
> eventManager.addListener(
> this,
> "dataContextDidRollback",
> DataContextEvent.class,
> DataContext.DID_ROLLBACK,
> this.getDataContext());
>
>
> //registers and fires the event
> eventManager.addListener(
> this,
> "dataContextDidRollback",
> GraphEvent.class,
> DataChannel.GRAPH_ROLLEDBACK_SUBJECT,
> this.getDataContext());
>
>
> On 30/10/06, edward pedersson <cpsmadnes..ooglemail.com> wrote:
>>
>> Hi
>>
>> I am trying to capture the a rollback event from the dataContext
>> and I
>> have tried variation of the code below but nothing seems to work.
>> My event
>> handlers never get called. I would have used the DataObject
>> jandlers but
>> they don't support rollBack.
>>
>> Can anyone see what I am doing wrong? Many thnaks for your help.
>>
>>
>>
>> public class SomeDataObject() extends MyDataObject {
>>
>>
>> public static DataContextTransactionEventListener
>> dataContextTransactionListener = new
>> DataContextTransactionEventListener() {
>>
>> public void dataContextDidCommit(DataContextEvent event) {
>> System.out.println("*** xxSomething changed! DID_COMMIT
>> ***");
>> }
>> public void dataContextDidRollback(DataContextEvent event) {
>> System.out.println("*** xxSomething changed! ROLLEDBACK
>> ***");
>> }
>> public void dataContextWillCommit(DataContextEvent event) {
>> System.out.println("*** xxSomething changed!
>> WILL_COMMIT
>> ***");
>> }
>> };
>>
>> public static DataChannelListener dataChannelListener = new
>> DataChannelListener() {
>> public void graphChanged(GraphEvent event) {
>> System.out.println("*** Something changed! DID_COMMIT
>> ***");
>> }
>> public void graphFlushed(GraphEvent event) {
>> System.out.println("*** Something changed!
>> ROLLEDBACK ***");
>> }
>> public void graphRolledback(GraphEvent event) {
>> System.out.println("*** Something changed! WILL_COMMIT
>> ***");
>> }
>> };
>>
>>
>> ..verride
>> public void fetchFinished() {
>>
>> super.fetchFinished ();
>> System.out.println("*** FETCH FINISHED! ***" +
>> this.toString());
>>
>> // this.getDataContext() is DataContext.getThreadedContext()
>>
>> this.getDataContext().setTransactionEventsEnabled(true);
>>
>> DataContext.setTransactionEventsEnabledDefault(true);
>>
>> EventUtil.listenForChannelEvents(this.getDataContext
>> ().getChannel(),
>> dataChannelListener);
>>
>> EventManager.getDefaultManager().addListener
>> (dataContextTransactionListener,"dataContextDidRollback",
>> DataContextEvent.class,DataContext.DID_ROLLBACK, null);
>> }
>>
>>
>> ....more methods
>> }
>>
>>
>> --
>>
>>
>> -- e
>
>
>
>
> --
>
>
> -- e



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