Re: Multiple persistance strategy

[Charlouze]

As for now, I solved my problem using a new PersistentFieldStrategy and I
want your opinion about it:

public class MultiplePersistentFieldStrategy implements
PersistentFieldStrategy {

    private final Logger logger;

    private final List<PersistentFieldStrategy> delegates;

    public MultiplePersistentFieldStrategy(final Logger logger,
            final List<PersistentFieldStrategy> delegates) {
        this.logger = logger;
        this.delegates = Lists.newArrayList(delegates);
    }

    @Override
    public void postChange(final String pageName, final String componentId,
final String fieldName,
            final Object newValue) {
        for (final PersistentFieldStrategy persistentFieldStrategy :
delegates) {
            try {
                persistentFieldStrategy.postChange(pageName, componentId,
fieldName, newValue);
                return;
            } catch (final RuntimeException e) {
                logger.debug("Error while using a PersistentFieldStrategy",
e);
            }
        }
        throw new IllegalArgumentException("Unable to find any suitable
PersistentFieldStrategy");
    }

    @Override
    public Collection<PersistentFieldChange> gatherFieldChanges(final
String pageName) {
        final List<PersistentFieldChange> persistentFieldChanges =
Lists.newArrayList();
        for (final PersistentFieldStrategy persistentFieldStrategy :
delegates) {

persistentFieldChanges.addAll(persistentFieldStrategy.gatherFieldChanges(pageName));
        }
        return persistentFieldChanges;
    }

    @Override
    public void discardChanges(final String pageName) {
        for (final PersistentFieldStrategy persistentFieldStrategy :
delegates) {
            persistentFieldStrategy.discardChanges(pageName);
        }
    }
}

Thanks again,

Charles.

2014-09-16 16:29 GMT+02:00 Charlouze <m...@charlouze.com>:

> Hello Tapestry users & devs,
>
> I have a component which does lots of ajax requests. Parameters setted at
> the first render are not available upon ajax requests so I decided to
> persist them in specific properties.
> One of those parameter is a database entity (I use tapestry-jpa) so I
> decided to use the the "entity" strategy so that my entity is reload and
> managed on every request.
> My problem is that when I use my component on a non persisted (yet)
> entity, it crashes as it is a transient entity that cannot be found.
>
> Do you think of a better way than creating my own persistence strategy ?
>
> Thx in advance :D
>