Subclassing AFNetworking to handle POST / GET requests

Question

I am pretty new to iOS development - I'm writing an app the uses web services, pretty extensively. With that in mind, I decided to use AFNetworking 2.0 and subclass AFHTTPSessionManager.

I created a method to build a URL for me - based on NSDictionary parameters and then I use the URL with the parameters to execute a GET / POST / PUT request. My worry is the last part - have I made this class less readable and less manageable by doing that?

BBWebService.h

#import <Foundation/Foundation.h>
#import "AFNetworking.h"
@interface BBWebService : AFHTTPSessionManager
@property (strong, nonatomic) NSData *responseData;


    //Designated Initilizer

- (id) initWithURL: (NSString*) url RequestType: (NSString*) requestType PostDataValuesAndKeys: (NSDictionary*) postData RequestProperties: (NSDictionary*) requestProperties UrlParameters: (NSDictionary*) urlParameters;


@end

BBWebService.m

import "BBWebService.h"

@interface BBWebService ()



@end
@implementation BBWebService

- (id) initWithURL: (NSString*) url RequestType: (NSString*) requestType PostDataValuesAndKeys: (NSDictionary*) postData RequestProperties: (NSDictionary*) requestProperties UrlParameters: (NSDictionary*) urlParameters 
{
    self = [super init];
    if (self)
        {
        NSString* urlWithParameters = [NSString stringWithString: url];

            // check to see if url parameters have been specified
        if (urlParameters != nil)
            {
            NSString *paramString = nil;

                // Work-around for URLs that may use a parameter to indicate an "action" instead of a path in the URL itself.
            BOOL hasQuestionMark = NO;
            NSRange textRange;
            textRange = [urlWithParameters rangeOfString:@"?"];

            if(textRange.location != NSNotFound)
                {
                hasQuestionMark = YES;
                }

            for (int i = 0; i < [[urlParameters allKeys] count]; i++)
                {
                if (i == 0)
                    {
                    if (hasQuestionMark == YES)
                        {
                        paramString = [NSString stringWithFormat: @"&%@=%@",
                                       [[urlParameters allKeys] objectAtIndex: i],
                                       [urlParameters objectForKey:[[urlParameters allKeys] objectAtIndex: i]]];
                        }
                    else
                        {
                        paramString = [NSString stringWithFormat: @"?%@=%@",
                                       [[urlParameters allKeys] objectAtIndex: i],
                                       [urlParameters objectForKey:[[urlParameters allKeys] objectAtIndex: i]]];
                        }


                    }
                else
                    {
                    paramString = [NSString stringWithFormat: @"%@&%@=%@", paramString,
                                   [[urlParameters allKeys] objectAtIndex: i],
                                   [urlParameters objectForKey:[[urlParameters allKeys] objectAtIndex: i]]];
                    }
                }

            urlWithParameters = [url stringByAppendingString:paramString];
            urlWithParameters = [urlWithParameters stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];

                NSLog(@"Url with encoded parameters: %@", urlWithParameters);
            }

 __unused   AFHTTPSessionManager* sessiomNamager = [BBWebService buildRequest:urlWithParameters RequestType:requestType PostDataValuesAndKeys:postData RequestProperties:requestProperties];

        }

    return self;
}


    //Class method

+ (AFHTTPSessionManager *) buildRequest: (NSString*) url RequestType: (NSString*) requestType PostDataValuesAndKeys: (NSDictionary*) postData  RequestProperties: (NSDictionary*) requestProperties
{

    AFHTTPSessionManager *manager = [AFHTTPSessionManager manager];
    manager.responseSerializer = [AFHTTPResponseSerializer serializer];


    if ([requestType isEqualToString:@"GET"])
        {
        [manager GET:url parameters:postData success:^(NSURLSessionDataTask *dataTask, id responseObject){

                //Success
            NSLog (@"Success");


        }
             failure:^(NSURLSessionDataTask *dataTask, NSError *error){

                     //Failure
                 NSLog (@"Failure");


             }];

        }else if ([requestType isEqualToString:@"POST"]){

            [manager POST:url parameters:postData success:^(NSURLSessionDataTask *dataTask, id responseObject){

                    //Success
                NSLog (@"Success!!");

            }
                  failure:^(NSURLSessionDataTask *dataTask, NSError *error){

                          //Failure
                      NSLog (@"Failure");


                  }];

        }else if ([requestType isEqualToString:@"PUT"]){

            [manager PUT:url parameters:postData success:^(NSURLSessionDataTask *dataTask, id responseObject){

                    //Success
            }
                 failure:^(NSURLSessionDataTask *dataDask, id responseObject){

                         //Failure
                 }];
        }


    return manager;
}


@end

Questions:

1. In my designated initWithURL method - is this a good way to build a URL based on NSDictionary parameters?

2. With the class method: builRequest - I looked in the header file of AFHTTPSessionManager.h - I couldn't see a way to properly detect the requestType (GET/POST, etc) - and this is why I am checking with an NSString value.

I worry that should someone else use this class and they type / spell the GET / POST part wrong - the service won't run and it may be a hard to track bug as the compiler won't show a warning for NSString values.

This is how I would use this method in another class:

BBWebService *newWebService = [[BBWebService alloc]initWithURL:URL RequestType:@"GET" PostDataValuesAndKeys:nil RequestProperties:nil UrlParameters:nil];

I am aware I have not added the class method to the header file - reason being is I am still finishing the rest of the file - and I have not decided yet if I want it exposed.

Answer 1

My first thought is does AFNetworking not handle this already but if not I would suggest doing this in a more AFNetworking style: create an object of type AFHTTPResponseSerializer * and set an instance of it as the session manager's requestSerializer property

This way you can use the default session managers request methods (i.e. using the get methods and not having to worry about spelling GET, POST etc correctly), and you can be responsible for how the request is formatted by implementing

- (NSURLRequest *)requestBySerializingRequest:(NSURLRequest *)request
                               withParameters:(NSDictionary *)parameters
                                        error:(NSError *__autoreleasing *)error;

Adding comment into answer: basically i think the request creation should happen in the requestSerializer object, not in the session manager itself. its ok to do this yourself (this is why AFNetworking provides the property to modify, and protocol to implement), but the session manager (subclass or not) isn't the place for it