AFNetworking 2.0, Mantle, NSURLSession API design

CRClient+Requests.h

//
//  CRClient+Requests.h
//  CRClient
//
//  Created by Christian Roman on 20/12/13.
//  Copyright (c) 2013 Christian Roman. All rights reserved.
//

#import "CRClient.h"
#import "CRCompletionBlocks.h"

@interface CRClient (Requests)

- (NSURLSessionDataTask *)requestWithMethod:(NSString *)method
                                       path:(NSString *)path
                                 parameters:(NSDictionary *)parameters
                                 completion:(CRResponseCompletionBlock)completion;

@end

CRClient+Requests.m

//
//  CRClient+Requests.m
//  CRClient
//
//  Created by Christian Roman on 20/12/13.
//  Copyright (c) 2013 Christian Roman. All rights reserved.
//

#import "CRClient+Requests.h"

@implementation CRClient (Requests)

- (NSURLSessionDataTask *)requestWithMethod:(NSString *)method
                                       path:(NSString *)path
                                 parameters:(NSDictionary *)parameters
                                 completion:(CRResponseCompletionBlock)completion
{
    NSParameterAssert(method);
    NSParameterAssert(path);
    
    NSString *URLString = [[NSURL URLWithString:path relativeToURL:self.baseURL] absoluteString];
    
    NSError *error;
    NSURLRequest *request = [[self requestSerializer] requestWithMethod:method URLString:URLString parameters:parameters error:&error];
    
    if(!error) {
        NSURLSessionDataTask *task = [self dataTaskWithRequest:request completionHandler:^(NSURLResponse *response, id responseObject, NSError *error) {
            if (completion) {
                completion((NSHTTPURLResponse *)response, responseObject, error);
            }
        }];
        
        [task resume];
        return task;
    }
    
    return nil;
}

@end

CRClient+Stores.h

//
//  CRClient+Stores.h
//  CRClient
//
//  Created by Christian Roman on 17/12/13.
//  Copyright (c) 2013 Christian Roman. All rights reserved.
//

#import "CRClient.h"
#import "CRCompletionBlocks.h"

@interface CRClient (Stores)

- (NSURLSessionDataTask *)getNearbyStoresFromLatitude:(float)latitude 
                                            longitude:(float)longitude
                                           completion:(CRArrayCompletionBlock)completion;

@end

CRClient+Stores.m

//
//  CRClient+Stores.m
//  CRClient
//
//  Created by Christian Roman on 17/12/13.
//  Copyright (c) 2013 Christian Roman. All rights reserved.
//

#import "CRClient+Stores.h"
#import "CRClient+Requests.h"
#import "Store.h"
#import "ObjectBuilder.h"

@implementation CRClient (Stores)

- (NSURLSessionDataTask *)getNearbyStoresFromLatitude:(float)latitude
                                            longitude:(float)longitude
                                           completion:(CRArrayCompletionBlock)completion
{
    NSParameterAssert(latitude);
    NSParameterAssert(longitude);
    
    NSDictionary *parameters = @{
                                 @"languagePreference" : @"es",
                                 @"detailLevel": @2,
                                 @"format" : @"json",
                                 @"radius" : @100,
                                 @"unit" : @1,
                                 @"limit" : @300,
                                 @"longitude" : @(longitude),
                                 @"latitude": @(latitude),
                                 @"brand" : @"stores"
                                 };
    
    NSString *path = @"stores/";
    
    NSString *URLString = [[NSURL URLWithString:path relativeToURL:self.baseURL] absoluteString];
    
    return [self GET:URLString parameters:parameters success:^(NSURLSessionDataTask *task, id responseObject) {
        
        if (!completion) {
            return;
        }
        
        if (responseObject) {
            
            dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
                    
                id collection = [[ObjectBuilder builder] collectionFromJSON:responseObject className:NSStringFromClass([Store class])];
                
                dispatch_async(dispatch_get_main_queue(), ^{
                    completion(collection, nil);
                });
                
            });
            
        } else {
            completion(nil, nil);
        }
        
    } failure:^(NSURLSessionDataTask *task, NSError *error) {
        
        if (completion) {
            completion(nil, error);
        }
        
    }];
}

@end

CRClient.h

//
//  CRClient.h
//  CRClient
//
//  Created by Christian Roman on 17/12/13.
//  Copyright (c) 2013 Christian Roman. All rights reserved.
//

#import "AFNetworking.h"

@interface CRClient : AFHTTPSessionManager

+ (instancetype)sharedClient;

@end

CRClient.m

//
//  CRClient.m
//  CRClient
//
//  Created by Christian Roman on 17/12/13.
//  Copyright (c) 2013 Christian Roman. All rights reserved.
//

#import "CRClient.h"

@interface CRClient ()

@property (nonatomic, strong) NSString *userAgent;

+ (NSURL *)APIBaseURL;

@end

@implementation CRClient

static NSString * const kCRClientAPIBaseURLString = @"http://api.stores.com/";

#pragma mark - Class Methods

+ (instancetype)sharedClient
{
    static dispatch_once_t onceQueue;
    static CRClient *__sharedClient = nil;
    dispatch_once(&onceQueue, ^{
        __sharedClient = [[self alloc] init];
    });
    return __sharedClient;
}

- (id)init
{
    if (self = [super initWithBaseURL:[[self class] APIBaseURL]])
    {
        self.requestSerializer = [AFHTTPRequestSerializer serializer];
        self.responseSerializer = [AFJSONResponseSerializer serializer];
        
        [self.requestSerializer setAuthorizationHeaderFieldWithUsername:@"username" password:@"password"];
    }
    
    return self;
}

+ (NSURL *)APIBaseURL
{
    return [NSURL URLWithString:kCRClientAPIBaseURLString];
}
 
@end

CRCompletionBlocks.h

//
//  CRCompletionBlocks.h
//  CRClient
//
//  Created by Christian Roman on 20/12/13.
//  Copyright (c) 2013 Christian Roman. All rights reserved.
//

typedef void (^CRCompletionBlock)(NSError *error);

typedef void (^CRResponseCompletionBlock)(NSHTTPURLResponse *response, id responseObject, NSError *error);

typedef void (^CRBooleanCompletionBlock)(BOOL result, NSError *error);

typedef void (^CRObjectCompletionBlock)(id object, NSError *error);

typedef void (^CRArrayCompletionBlock)(NSArray *collection, NSError *error);

Example.m

//...

[[CRClient sharedClient] getNearbyStoresFromLatitude:(float)latitude longitude:(float)longitude completion:^(NSArray *stores, NSError *error) {
        if (!error){
            NSLog(@"%@", stores);
        }
    }];

ObjectBuilder.h

//
//  ObjectBuilder.h
//  CRClient
//
//  Created by Christian Roman on 20/12/13.
//  Copyright (c) 2013 Christian Roman. All rights reserved.
//

#import <Foundation/Foundation.h>

@interface ObjectBuilder : NSObject

+ (instancetype)builder;
- (id)objectFromJSON:(NSDictionary *)JSON className:(NSString *)className;
- (id)collectionFromJSON:(NSDictionary *)JSON className:(NSString *)className;

@end

ObjectBuilder.m

//
//  ObjectBuilder.m
//  CRClient
//
//  Created by Christian Roman on 20/12/13.
//  Copyright (c) 2013 Christian Roman. All rights reserved.
//

#import "ObjectBuilder.h"
#import <Mantle/Mantle.h>

@implementation ObjectBuilder

+ (instancetype)builder
{
    static dispatch_once_t onceQueue;
    static ObjectBuilder *__builder = nil;
    dispatch_once(&onceQueue, ^{
        __builder = [[ObjectBuilder alloc] init];
    });
    
    return __builder;
}

- (id)objectFromJSON:(NSDictionary *)JSON className:(NSString *)className
{
    NSParameterAssert(className);
    
    NSError *error = nil;
    id model = [MTLJSONAdapter modelOfClass:NSClassFromString(className) fromJSONDictionary:JSON error:&error];
    
    if (!error) {
        return model;
    } else {
        return nil;
    }
}

- (id)collectionFromJSON:(NSDictionary *)JSON className:(NSString *)className
{
    NSParameterAssert(className);
    
    if ([JSON isKindOfClass:[NSArray class]]) {
        
        NSValueTransformer *valueTransformer = [MTLValueTransformer mtl_JSONArrayTransformerWithModelClass:NSClassFromString(className)];
        NSArray *collection = [valueTransformer transformedValue:JSON];
        return collection;
        
    }
    return nil;
}

@end

Store.h

//
//  Store.h
//  Example
//
//  Created by Christian Roman on 17/12/13.
//  Copyright (c) 2013 Christian Roman. All rights reserved.
//

#import <Mantle/Mantle.h>

@interface Store : MTLModel <MTLJSONSerializing>

@property (nonatomic, copy, readonly) NSString *address1;
@property (nonatomic, copy, readonly) NSString *address2;
@property (nonatomic, copy, readonly) NSString *features;
@property (nonatomic, copy, readonly) NSNumber *ID;
@property (nonatomic, copy, readonly) NSNumber *lat;
@property (nonatomic, copy, readonly) NSNumber *lng;
@property (nonatomic, copy, readonly) NSString *name;
@property (nonatomic, copy, readonly) NSNumber *open24HrsToday;
@property (nonatomic, copy, readonly) NSNumber *openNow;
@property (nonatomic, copy, readonly) NSString *phone;
@property (nonatomic, copy, readonly) NSString *store;

@end

Store.m

//
//  Store.m
//  Example
//
//  Created by Christian Roman on 17/12/13.
//  Copyright (c) 2013 Christian Roman. All rights reserved.
//

#import "Store.h"

@implementation Store

+ (NSDictionary *)JSONKeyPathsByPropertyKey
{
    return @{
             @"address1" : @"Addr1",
             @"address2" : @"Addr2",
             @"features" : @"Features",
             @"ID": @"Id",
             @"lat" : @"Lat",
             @"lng" : @"Long",
             @"name" : @"Name",
             @"open24HrsToday" : @"Open24HrsToday",
             @"phone" : @"Phone",
             @"store" : @"Store"
             };
}

- (NSString *)description
{
    return [NSString stringWithFormat:@"<%@: %p, ID: %@, name: %@>", NSStringFromClass([self class]), self, self.ID, self.name];
}

@end