RestKit dynamic nesting attributes

Question

I'm trying to map an API result that has dynamic nested attributes. The result (json) is I have is this:

{
    "url": "https://api.github.com/gists/8901308",
    "id": "8901308",
    "html_url": "https://gist.github.com/8901308",
    "files": {
        "node-and-npm-in-30-seconds.sh": {
            "filename": "node-and-npm-in-30-seconds.sh",
            "type": "application/sh",
            "language": "Shell",
            "raw_url": "https://gist.github.com/braincrash/8901308/raw/bae861f7c4ab0c1ffd9962439e770b02f52c5dd7/node-and-npm-in-30-seconds.sh",
            "size": 352
        },
        "only-git-all-the-way.sh": {
            "filename": "only-git-all-the-way.sh",
            "type": "application/sh",
            "language": "Shell",
            "raw_url": "https://gist.github.com/braincrash/8901308/raw/eba9667b37218ffb41892411c94abd051b0e269a/only-git-all-the-way.sh",
            "size": 440
        }
    }
}

I can get all the attributes, but the files won't work. Here's my mapping:

RKEntityMapping *fileMapping = [RKEntityMapping mappingForEntityForName:@"File" inManagedObjectStore:managedObjectStore];

fileMapping.forceCollectionMapping = YES;
[fileMapping addAttributeMappingFromKeyOfRepresentationToAttribute:@"filename"];
[fileMapping addAttributeMappingsFromDictionary:@{@"(filename).raw_url": @"rawURL",
                                                  @"(filename).size": @"size"}];

RKEntityMapping *gistMapping = [RKEntityMapping mappingForEntityForName:@"Gist" inManagedObjectStore:managedObjectStore];
[gistMapping addAttributeMappingsFromDictionary:@{
                                                  @"id":             @"gistID",
                                                  @"url":            @"jsonURL",
                                                  @"html_url":            @"htmlURL"}];
gistMapping.identificationAttributes = @[ @"gistID" ];

[gistMapping addPropertyMapping:[RKRelationshipMapping relationshipMappingFromKeyPath:@"files" toKeyPath:@"files" withMapping:fileMapping]];

RKResponseDescriptor *responseDescriptor = [RKResponseDescriptor responseDescriptorWithMapping:gistMapping method:RKRequestMethodGET pathPattern:@"/gists/public" keyPath:nil statusCodes:RKStatusCodeIndexSetForClass(RKStatusCodeClassSuccessful)];

When I look at the File inside the Gist object, I only get the filename, but not the url nor size:

filename = "radiation.js";
gist = "0xb9742f0 <x-coredata://D37E442D-45BA-4A0E-B7A5-A349F75FA362/Gist/p21>";
rawURL = nil;
size = 0;

Thanks for the help!!

Probably because your file names contain dots so they will mess up key path navigation. Turn on trace logging to check. Do you have the option to change the JSON? — Wain
You are wright. I found a key without the dots and worked fine. Yo can add an answer with that and I'll mark it as correct. Do you know any workaround to this problem? Thanks — amcastror

Wain Wain · Accepted Answer · 2014-02-10T15:14:47

Your file names contain dots so they will mess up key path navigation.

RestKit does struggle with this a little and I don't think there is currently a solution. Some have been proposed (https://github.com/RestKit/RestKit/pull/1541/files) but I think it remains an open issue.

The problem is how to know whether a dot represents a key path to the traversed or not. In theory it is possible to determine but it isn't necessarily trivial to implement in a framework or performant. You may be able to debug around the usage of RKObjectMappingNestingAttributeKeyName and add a custom solution just for that part.

RestKit dynamic nesting attributes

1 Answers