writing an API class for RestKit framework - ios

Question

I switched from AFnetworking to RestKit. In AFnetworking had an API class. The API.h class contained the following.
#import <UIKit/UIKit.h>
typedef void (^JSONResponseBlock)(NSDictionary* json);
#interface API : NSObject
//the authorized user
#property (strong, nonatomic) NSDictionary* user;
+(API*)sharedInstance;
//check whether there's an authorized user
//send an API command to the server
-(void)loginCommand:(NSMutableDictionary*)params onCompletion:(JSONResponseBlock)completionBlock;
And my API.m class looks like this.
+(API *)sharedInstance
{
static API *sharedInstance = nil;
static dispatch_once_t oncePredicate;
dispatch_once(&oncePredicate, ^ {
sharedInstance = [[self alloc]initWithBaseURL:[NSURL URLWithString:kAPIHost]];
});
return sharedInstance;
}
#pragma mark - init
//intialize the API class with the destination host name
-(API *)init
{
//call super init
self = [super init];
if (self != nil){
//initialize the object
user = nil;
[self registerHTTPOperationClass:[AFJSONRequestOperation class]];
// Accept HTTP Header; see http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.1
[self setDefaultHeader:#"Accept" value:#"application/json"];
}
return self;
}
-(void)loginCommand:(NSMutableDictionary *)params onCompletion:(JSONResponseBlock)completionBlock{
NSLog(#"%#%#",kAPIHost,kAPILogin);
NSMutableURLRequest *apiRequest = [self multipartFormRequestWithMethod:#"POST" path:kAPILogin parameters:params constructingBodyWithBlock:^(id <AFMultipartFormData>formData){
//TODO: attach file if needed
}];
AFJSONRequestOperation *operation = [[AFJSONRequestOperation alloc] initWithRequest:apiRequest];
[operation setCompletionBlockWithSuccess:^(AFHTTPRequestOperation *operation, id responseObject){
//success!
NSLog(#"SUCCESSSS!");
completionBlock(responseObject);
}failure:^(AFHTTPRequestOperation *operation, NSError *error){
//Failure
NSLog(#"FAILUREE!");
completionBlock([NSDictionary dictionaryWithObject:[error localizedDescription] forKey:#"error"]);
}];
[operation start];
}
Like you can see I only instantiate it once and put all my methods in over here. In my view controller I only need to call this method with a parameter-dictionary. Then I could read the whole JSON file.
Now with restKit I do this all on viewController level. I want to split it up like I did by AFNetworking. This is what I do in RestKit, At the moment is this all on viewController level.
//let AFNetworking manage the activity indicator
[AFNetworkActivityIndicatorManager sharedManager].enabled = YES;
// Initialize HTTPClient
NSURL *baseURL = [NSURL URLWithString:#"http://virtuele-receptie.preview.sanmax.be"];
AFHTTPClient* client = [[AFHTTPClient alloc] initWithBaseURL:baseURL];
//we want to work with JSON-Data
[client setDefaultHeader:#"Accept" value:RKMIMETypeJSON];
// Initialize RestKit
RKObjectManager *objectManager = [[RKObjectManager alloc] initWithHTTPClient:client];
//Do mapping
RKResponseDescriptor *responseDescriptor = [RKResponseDescriptor responseDescriptorWithMapping:dataMapping
pathPattern:nil
keyPath:#"data"
statusCodes:[NSIndexSet indexSetWithIndex:200]];
[objectManager addResponseDescriptor:responseDescriptor];
NSDictionary *dict = [[NSDictionary alloc]initWithObjectsAndKeys:_txtLogin.text,#"email",_txtPass.text,#"pwd", nil];
[objectManager getObject:nil path:#"/nl/webservice/company-user/login/apikey/key12345678" parameters:dict
success:^(RKObjectRequestOperation *operation, RKMappingResult *mappingResult) {
//Success
}
failure:^(RKObjectRequestOperation *operation, NSError *error) {
//Failure
}];

Answer 1

So far with RestKit I haven't seen a huge need for an API class like you might create with other HTTP frameworks. RestKit has its own HTTP client (actually, just AFNetworking's client), so there's no need to have a class for your HTTP client, and I've found that each time I use the RKObjectManager I generally want access to the method parameters and block callbacks within each view controller. In other words, I don't want to run RestKit networking code in an API class, because I would essentially have to wrap the entire call in a method that can be accessed in the view controller (success block, failure block, etc).
In essence, RestKit's design lightens the networking code so much that in my experience with it - 3 or 4 apps now - I've yet to see enough reason write an API class like you describe.