NSOrderedSet support

[bmorton]

This fixes issue #483 and adds support for NSOrderedSet in RKObjectMappingOperation. I've added a test to add coverage for the mapping, does anything need to be added to test core data or that issue more specifically?

[blakewatters]

Great work here Brian. There should probably be an additional test serializing an NSOrderedSet to an array. That will cover the serialization use-case.

[bmorton]

Good to go.

[blakewatters]

Brian -

Thanks for the contribution! Welcome to the RestKit contributor community :-D

• Blake

[bmorton]

Thanks! I look forward to many more :)

[f1337]

NSOrderedSet is only available for iOS 5+. RestKit does not compile in my iOS 4.x projects unless I comment-out this NSOrderedSet support. How do you feel about a compiler flag around the NSOrderedSet lines?

[bmorton]

Good call. I'll take a look at this today and throw something together.

[martijnwalraven]

Support for NSOrderedSet in applyRelationshipMappings: in RKObjectMappingOperation is still missing. This seems to work for me:

// If the relationship has changed, set it
[...]
    } else if ([destinationObject isKindOfClass:[NSOrderedSet class]]) {
        RKLogTrace(@"Mapped NSOrderedSet relationship object from keyPath '%@' to '%@'. Value: %@", relationshipMapping.sourceKeyPath, relationshipMapping.destinationKeyPath, destinationObject);
        [self.destinationObject setValue:destinationObject forKey:relationshipMapping.destinationKeyPath];
    }

We're not able to use mutableOrderedSetValueForKey: because NSMutableOrderedSet doesn't have a method like setOrderedSet: to replace the whole collection.