[seam-dev] [forge-dev] SAF (aka Entity Framework) idea in Seam 3

[José Rodolfo Freitas]

Sorry for not being able to post my gist. After writting some "sketches", I
realized that I don't have it very clear in my mind yet.

just to move from zero I posted something:

https://gist.github.com/1245041

It's a really simple example on how we could avoid inheritance,  but it's
not contemplating a lot of needed features,
so I'm not even near to be convinced with that gist.

btw, the @AutoHome approach seems very nice.


On Thu, Sep 22, 2011 at 2:12 PM, Dan Allen <dan.j.allen at gmail.com> wrote:

> Exactly. flush() has a specific purpose and really doesn't belong in
> boilerplate code.
>
> - Dan Allen
>
> Sent from my Android-powered phone:
> An open platform for carriers, consumers and developers
> On Sep 22, 2011 11:19 AM, "Max Rydahl Andersen" <max.andersen at redhat.com>
> wrote:
> > just one comment:
> >
> > Calling .flush() on every alteration really should not be promoted as a
> good practice.
> >
> > /max
> >
> > On Sep 22, 2011, at 24:22, Dan Allen wrote:
> >
> >> Here's some additional feedback I received from a community member a
> while back...to merge it into this thread.
> >>
> >> (begin feedback)
> >>
> >> ...from being burned from 3 seam based customers with apps and
> maintenance. The "Home" or any other name should be just be put into a grave
> and slowly cast away to sea ;). It is too heavy and complicated and just
> about anything inherited (extends) truly causes heartache[Favor Composition
> over inheritance: Effective Java]. The current seam home has a few super
> classes above the home and when you try to unit test it (the standard
> definition of unit-testing including isolation) you get the "No Active
> Application Context Found (if I remember it right). That happens because it
> is tightly coupled with the application. But not to be hard on Home, I do
> realize the history of the home object and know it was developed when EL had
> no parameters. So I have learned a lot since then and I here are some things
> that I can impart to Seam 3.
> >>
> >> 1. My "Home" now is a "ServiceBean", and I have one for each "Major"
> entity, see below. I have really stewed over this over months and months,
> and the "Home" of "ServiceBean" should be kept small, focused, reusable,
> tested and untouched. It's only task is to update, persist, possibly remove,
> or some other functions that are required. In my example below I have custom
> close action. Notice also that although these beans are stateful that
> doesn't mean everything should be, so in these methods I have the parameter
> of what is being needed to be updated, and not a field. In other words I
> don't have @In private Job job, I opted for public boolean update(job).
> Mostly because, again, I want to make this service bean reusable so whether
> I have a #{newJob}, #{copyOfAJob}, or #{managedJob} or whatever component of
> job I need to work on I only need one jobServiceBean to cater to all my
> jobs, in whatever conversation I am using. I also fire events from here if I
> need to do that. !
> > After this is tested, and what I need I usually don't touch it anymore.
> If I need to enhance I either use a decorator pattern around it, or enhance
> it in an @Observer. I'll email about that later.
> >>
> >> @Name("jobServiceBean")
> >> @Scope(ScopeType.CONVERSATION)
> >> public class JobServiceBean implements JobService {
> >> private EntityManager entityManager;
> >> private StatusMessages statusMessages;
> >>
> >> @In
> >> public void setEntityManager(EntityManager entityManager) {
> >> this.entityManager = entityManager;
> >> }
> >>
> >> @In
> >> public void setStatusMessages(StatusMessages statusMessages) {
> >> this.statusMessages = statusMessages;
> >> }
> >>
> >> public boolean update(Job job) {
> >> this.entityManager.flush();
> >> this.statusMessages.add(StatusMessage.Severity.INFO, "Successfully
> updated job {0}", job.getName());
> >> return true;
> >> }
> >>
> >> public boolean close(Job job) {
> >> job.setJobStatus(JobStatus.CLOSED);
> >> this.entityManager.flush();
> >> this.statusMessages.add(StatusMessage.Severity.INFO, "Successfully
> closed job {0}", job.getName());
> >> return true;
> >> }
> >> }
> >>
> >> 2. One thing you may have noticed from above that there is no 'instance'
> field with corresponding getters or setters like the old 'Home'. So the
> ServiceBean in my case is not a full crud, but CUD + your own business
> methods. That's because that too should be decoupled because we never know
> the source of the object is. Is the object created from a factory? from a
> copy? is it a mapped component, a managed component? Creation of objects or
> loading of objects, or the manufacturing of objects from factories should be
> separate from the "home" or in my case the "ServiceBean".
> >>
> >> (end feedback)
> >>
> >> --
> >> Dan Allen
> >> Principal Software Engineer, Red Hat | Author of Seam in Action
> >> Registered Linux User #231597
> >>
> >> http://www.google.com/profiles/dan.j.allen#about
> >> http://mojavelinux.com
> >> http://mojavelinux.com/seaminaction
> >>
> >> _______________________________________________
> >> forge-dev mailing list
> >> forge-dev at lists.jboss.org
> >> https://lists.jboss.org/mailman/listinfo/forge-dev
> >
> > /max
> > http://about.me/maxandersen
> >
> >
> >
> >
> > _______________________________________________
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>
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