MTLModels within MTLModels?

Question

I have a web service that returns a JSON of an object, and within that object there is a list of other objects. How can I get Mantle to create an object for each one of these nested objects, rather than giving me a dictionary for each one of them?

possible duplicate of [How to specify child objects type in an NSArray with Mantle](http://stackoverflow.com/questions/13883693/how-to-specify-child-objects-type-in-an-nsarray-with-mantle) — David Snabel-Caunt, Sep 17 '13 at 14:55

score 12 · Accepted Answer · edited Mar 03 '16 at 22:18

This can be done using mtl_JSONDictionaryTransformerWithModelClass: tranformer introduced by Mantle some time ago.

Let's look at the example taken from Mantle project readme itself:

@interface GHIssue : MTLModel <MTLJSONSerializing>

@property (nonatomic, strong, readonly) GHUser *assignee;

@end

@implementation GHIssue

+ (NSDictionary *)JSONKeyPathsByPropertyKey {
    return @{
        @"assignee": @"assignee",
    };
}

+ (NSValueTransformer *)assigneeJSONTransformer {
    return [NSValueTransformer mtl_JSONDictionaryTransformerWithModelClass:[GHUser class]];
}

@end

Assuming GHUser is a subclass of MTLModel conforming to MTLJSONSerializing protocol, everything should work perfectly.

UPDATE: The above solution is now deprecated. The correct method to use now would be

return [MTLJSONAdapter dictionaryTransformerWithModelClass:GHUser.class];

inside the 'assigneeJSONTransformer' method.

This fails if assignee field is empty/null. How can I check that and skip transformation in this case? — Borut Tomazin, Oct 06 '14 at 12:05

MTLModels within MTLModels?

1 Answers1