I'm not suprised this has come up again - Transfer is so close to being a
really cool object factory (and a really cool cache, and a really cool code
generator - basically the persistence is just the icing on the cake).
One of the issues in using Transfer this way is in managing the object
lifecycle. If you ask Transfer for any object, it will always return one -
whether it exists in the database or not. You then use getIsPersisted(), or
maybe just check if the ID is 0. This makes sense for an ORM, but is
fundamentally not how you want an object factory to behave. You *can*
create stub factories that return TransferObjects populated with some
sequential ID, but you can't then mix that with persistence, and at the end
of the day it's just as easy to set up a database.
Jaime
On Thu, Nov 20, 2008 at 2:05 AM, John K. <[EMAIL PROTECTED]> wrote:
>
> I didn't mean to make anyone go out and code this up for me to see if
> it worked, I was really just curious how others handled this problem.
> Thanks for trying it out though Chris!
>
> I did try it out last night myself and it worked just fine. The only
> trick was to dummy up a primary key, as Chris has done as well. In
> this case I just used the name of the person submitting the contact
> form.
>
> Most objects in a site/application are probably persisted in some way
> but there are a few that never need to be. At work we have two
> different methods we use for persisted and non-persisted data, but it
> seems kind of messy to me since 95% of the logic is the same. The
> only difference in this case is that instead of calling .save() I am
> sending an email and then throwing the data away.
>
> The only thing that get's a little messy, in my implementation, is the
> fact that I have my application set up with MG and CS and so I have
> the view, controllers, services, and then gateways/dao's. Instead of
> exposing Transfer to the service level and using it to replace all my
> gateway/dao functionality, I expose Transfer at the gateway/dao level
> as more of a wrapper. Change the ORM, change the gateways/daos
> instead of the entire service layer. You might be able to imagine how
> this kind of creates some goofiness as I have to have a method in the
> gateway that creates the empty Transfer object for me. It works, but
> I'm not entirely happy with it at the moment.
>
> If anyone else has any comments on how they accomplish this I'd love
> to hear them. And Mark, thank's for checking in to see if this worked
> and for saving me plenty of time that otherwise would have been wasted
> persisting data!
>
> John
>
>
> On Nov 19, 4:55 am, "Chris Peterson" <[EMAIL PROTECTED]> wrote:
> > Sure enough, I setup a simple transfer xml for a non-existing object:
> >
> > <object name="phantom" table="notReal">
> > <id name="ID" type="numeric" />
> > <property name="name" type="string" column="name" />
> > </object>
> >
> > Then I used it, as such:
> >
> > application.cs.getBean("transfer").new("phantom")
> >
> > and it dumped out exactly what I would expect, a transfer object of type
> > phantom, and I could use setName("foo") without any problems. Sounds
> like
> > an interesting method of using transfer for transient-persistance, kinda
> > cool. Maybe you could even write a save() method on there, to commit it
> to
> > another data location other than the database? Might be a cool way of
> > wrapping up all different data locations in a standardized way. Cool
> stuff,
> > good idea =)
> >
> > Chris Peterson
> >
> >
> >
> > On Wed, Nov 19, 2008 at 3:42 AM, Mark Mandel <[EMAIL PROTECTED]>
> wrote:
> >
> > > What happens if you create the objects with a table/columns that don't
> > > exist?
> >
> > > As long as you don't save() or get(), you shouldn't get errors.
> >
> > > Mark
> >
> > > On Wed, Nov 19, 2008 at 6:48 PM, Jared Rypka-Hauer
> > > <[EMAIL PROTECTED]> wrote:
> >
> > > > No, this isn't something that Transfer does... it has to have the
> > > > database there to provide properties for the objects, so without a DB
> > > > table you have nothing to provide the object definition. I think it
> > > > would be sweet if Transfer's config would provide a way to configure
> > > > it with objects outside the DB model that you could simply retrieve
> > > > from the Transfer object... making it into an object factory as well
> > > > as a persistence engine.
> >
> > > > You might try creating an object tagset that doesn't have a DB table
> > > > and then calling new() against it, but I think that would fail when
> > > > Transfer tried to create the metadata for the object.
> >
> > > > Something to think about, anyway.
> >
> > > > J
> >
> > > > On Nov 18, 2008, at 10:15 PM, John K. wrote:
> >
> > > >> So I've encountered this problem a few times and each time I seem to
> > > >> stumble on figuring out how to best solve it. Sorry if this has
> been
> > > >> discussed here, I looked through pages and pages and did some
> searches
> > > >> but came up with nothing.
> >
> > > >> The site I am designing has several objects (dogs, calendar events,
> > > >> ads, etc.). These all need to be created in the database, updated,
> > > >> etc. Perfect opportunity to use Transfer to make these database
> > > >> functions simple. I am able to set this up just fine and have
> > > >> incorporated validation into the works so that the data the user
> > > >> submits can be validated server side and returned to the form for
> > > >> corrections if necessary.
> >
> > > >> My problem comes in when I start to work with things like a contact
> > > >> form. I really want all the functionality of a Transfer object,
> > > >> except I'll never have to interact with the database. I will just
> > > >> validate, return the user to the form to correct errors (invalid
> email
> > > >> address, missing info, etc.) if necessary and then once the
> submission
> > > >> is valid I'll send an email to the proper administrator.
> >
> > > >> Has anyone used Transfer in this way? How so? Is it just as simple
> > > >> as mocking up and using the object but never saving the data? Have
> > > >> you come up with a better way to make this work? Maybe it's just
> late
> > > >> and this is as simple as it sounds.
> >
> > > >> John
> >
> > > --
> > > E: [EMAIL PROTECTED]
> > > W:www.compoundtheory.com
> >
> > --
> > Hey! I dont tell you how to tell me what to do, so dont tell me how to do
> > what you tell me to do! ~ Bender (Futurama)
> >
>
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