On Tuesday, February 14, 2012 at 1:37 AM, Bob Spryn wrote:
> One further thing, my question about syncing is less along the lines
> of the post you pointed to (we actually have an almost identical
> setup) but more along the lines of the one to many relationship, or
> even more difficult a relationship going in both directions. Looks
> like the answer is pretty much the same. Restkit doesn't have that
> magic yet, and it would be custom code to handle it.

> On Feb 13, 5:46 pm, Dave Thompson <th03p...@gmail.com (http://gmail.com)> wrote:
> > Bob,

> > I picked up your mail. I'm fairly new to RestKit myself and probably
> > not the best person to answer all of your queries, but I'll take a
> > stab.

> > Let me paraphrase your thoughts into four questions:

> > 1) Is it possible to load two linked entities from two distinct JSON
> > payloads received at different times, such that a Core Data
> > relationship is hydrated between them at the time the second entity is
> > loaded?

> > Yes.

> > 2) How can this be done for 1-to-many relationships?

> > Where your Daughter entity is received after your Mother entity has
> > already been received and loaded, this is straightforward and
> > described in my response tohttp://groups.google.com/group/restkit/browse_thread/thread/c89d0bbb9....
> > As well as the steps I describe there, you'll need to make sure you
> > have the primary key set up on the Mother entity. In that example,
> > this would be done as: teamMapping.primaryKeyAttribute = @"teamId";.

> > 3) How can this be done for many-to-1 relationships?

> > Where your Mother entity is received after your Daughter entity has
> > already been received and loaded, things are trickier. There is no
> > built in RestKit support for this, as outlined in the questionhttp://groups.google.com/group/restkit/browse_thread/thread/cb5800bad...
> > . (An array of IDs doesn't work, nor do I think that would be a very
> > good implementation.) I therefore see two options that you have:

> > (a) Fork RestKit, add this functionality to it, and use your forked
> > copy of RestKit in your app. I don't know RestKit's internals, but my
> > gut feel is that this shouldn't be too difficult, given that the
> > implementation for (2) above already exists. This will likely result
> > in the cleanest implementation for your app. If you go down this
> > route, I'm sure they would be other people who would appreciate you
> > submitting the update back to Blake for inclusion in RestKit proper.

> > (b) Write some custom code within the objectLoader:didLoadObjects:
> > method in your RKObjectLoader delegate that handles the loading of the
> > Mother objects. For every Mother object loaded, retrieve the set of
> > Daughter objects with daughter.motherID == mother.motherID and
> > daughter.mother == nil. For every Daughter object in that set, set
> > daughter.mother = mother. (Recall from the linked question above that
> > Daughter objects must have both the relationship daughter.mother and
> > also the redundant foreign key daughter.motherID defined, to enable
> > RestKit's mapping.) This is the most straightforward solution to (3),
> > but your code will inevitable be less clean cut than if you did (a)
> > above.

> > 4) How does this fit into my syncing solution?

> > RestKit is not itself a syncing solution. As any specific syncing
> > solution is highly dependent on business rules, you'll most likely
> > need to build your own. There is a question on StackOverflow that I
> > think is very useful for this:http://stackoverflow.com/questions/5035132/how-to-sync-iphone-core-da...
> > . I personally find chris's answer to that question more useful than
> > the accepted answer, and will likely build my own syncing solution in
> > a similar manner to that he describes.

> > RestKit will, however, be hugely useful in managing the server
> > communication and object mapping within whatever syncing solution you
> > end up with.

> > I hope that helps,
> > Dave

> > On Feb 13, 5:16 am, Bob Spryn <bobsp...@gmail.com (http://gmail.com)> wrote:

> > > Bumping this as I'm sort of spinning my wheels until I figure this
> > > out.

> > > On Feb 8, 4:01 pm, Bob Spryn <bobsp...@gmail.com (http://gmail.com)> wrote:

> > > > So I'm trying to put together the proper procedure for doing
> > > > relationship mapping with keys instead of embedding the objects in the
> > > > json, as the embedding piece is really hammering our API and timeouts
> > > > are occurring.

> > > > I was looking at this other thread:http://groups.google.com/group/restkit/browse_thread/thread/b30075024...

> > > > Is there some documentation or an example somewhere of the exact
> > > > correct way to do this?

> > > > My followup question is this: Once my mapping with id's is working,
> > > > how should I perform an initial sync to pull down all the data? How
> > > > does this work when objects may be pointing via id relationship to
> > > > other objects that don't yet exist in core data? Is it going to make
> > > > an individual http request in the middle of a large request for a
> > > > singular object because of the relationship, or will it somehow batch
> > > > all these together?

> > > > Best,
> > > > Bob