AFHTTPClient+MTLModel.h

//
//  AFHTTPClient+MTLModel.h
//  MXProjects
//
//  Created by Maxwell Swadling on 2/03/13.
//  Copyright (c) 2013 Maxwell Swadling. All rights reserved.
//

#import <AFNetworking/AFNetworking.h>
#import <Mantle.h>

@interface AFHTTPClient (MTLModel)

- (AFHTTPRequestOperation *)getObjects:(NSString *)path
                              forClass:(Class<MTLJSONSerializing>)klass
                             onKeypath:(NSString *)keypath
                            withParams:(NSDictionary *)params
                               success:(void (^)(NSURLRequest *request, NSHTTPURLResponse *response, NSArray *objects, id JSON))success
                               failure:(void (^)(NSURLRequest *request, NSHTTPURLResponse *response, NSError *error, id JSON))failure;

@end

AFHTTPClient+MTLModel.m

//
//  AFHTTPClient+MTLModel.m
//  MXProjects
//
//  Created by Maxwell Swadling on 2/03/13.
//  Copyright (c) 2013 Maxwell Swadling. All rights reserved.
//

#import "AFHTTPClient+MTLModel.h"

@implementation AFHTTPClient (MTLModel)


- (AFHTTPRequestOperation *)getObjects:(NSString *)path
                              forClass:(Class<MTLJSONSerializing>)klass
                             onKeypath:(NSString *)keypath
                            withParams:(NSDictionary *)params
success:(void (^)(NSURLRequest *request, NSHTTPURLResponse *response, NSArray *objects, id JSON))success
failure:(void (^)(NSURLRequest *request, NSHTTPURLResponse *response, NSError *error, id JSON))failure {
    NSURLRequest *request = [self requestWithMethod:@"GET" path:path parameters:params];
    AFHTTPRequestOperation *op = [AFJSONRequestOperation JSONRequestOperationWithRequest:request success:^(NSURLRequest *request, NSHTTPURLResponse *response, id JSON) {
        id objJSON = [JSON copy];
        NSMutableArray *buff = [[NSMutableArray alloc] initWithCapacity:0];
        NSMutableArray *objects = [[NSMutableArray alloc] initWithCapacity:0];
        
  	NSArray *keyPathComponents = [keypath componentsSeparatedByString:@"."];
        for (NSString *path in keyPathComponents) {
            if ([objJSON isKindOfClass:[NSArray class]]) {
                // Array, apply future keypaths to objects via map
                [buff removeAllObjects];
                [objJSON enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
                    [buff addObject:obj[path]];
                }];
                objJSON = buff;
                
            } else if ([objJSON isKindOfClass:[NSDictionary class]]) {
                // Dict, take value and repeat
                objJSON = objJSON[path];
                
            } else {
                // TODO: Error
                
            }
        }
        
        [objJSON enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
            [objects addObject:[MTLJSONAdapter modelOfClass:klass fromJSONDictionary:obj]];
        }];
        
        success(request, response, [NSArray arrayWithArray: objects], JSON);
    } failure:failure];
    return op;
}

@end