Working With

AFNetworking

@waynehartman

Before AFNetworking

• NSURLConnection (meh)

• NSData (BARF!)

• CFNetwork (medic!)

NSURLConnection - (IBAction)didSelectRefreshButton:(id)sender { NSURL *url = [NSURL URLWithString:@"http://ip.jsontest.com/"]; NSURLRequest *request = [NSURLRequest requestWithURL:url]; ! self.connection = [[NSURLConnection alloc] initWithRequest:request delegate:self startImmediately:YES]; } !#pragma mark - NSURLConnection !- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSHTTPURLResponse *)response { _data = nil; ! switch (response.statusCode) { case 200: { self.data = [NSMutableData dataWithCapacity:(NSUInteger)response.expectedContentLength]; } break; default: { [connection cancel]; ! NSError *error = [NSError errorWithDomain:(NSString *)kCFErrorDomainCFNetwork code:response.statusCode userInfo:@{(NSString *)kCFErrorDescriptionKey : (NSString *)kCFURLErrorFailingURLErrorKey}]; [self connection:connection didFailWithError:error]; } break; } } !- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data { [self.data appendData:data]; } !- (void)connectionDidFinishLoading:(NSURLConnection *)connection { NSError *error = nil; NSDictionary *jsonData = [NSJSONSerialization JSONObjectWithData:self.data options:0 error:&error]; if (!jsonData) { UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Error" message:@"The data was corrupt. Sorry" delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil]; [alert show]; } else { NSString *ip = jsonData[@"ip"]; UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Success!" message:[NSString stringWithFormat:@"Your IP is: %@", ip] delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil]; [alert show]; } ! self.connection = nil; } !- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error { UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Error" message:@"There was an error getting the data. Please try again later." delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil]; [alert show]; self.connection = nil; }

• All this code, just to download and display this:

{"ip": "72.191.49.142"}

NSData• One line of code! !

dataWithContentsOfURL: !

NEVER USE THIS API!

CFNetwork NSURL *url = [NSURL URLWithString:DOWNLOAD_URL]; ! CFHTTPMessageRef request = CFHTTPMessageCreateRequest(NULL, CFSTR("GET"), (__bridge CFURLRef)url, kCFHTTPVersion1_1); ! CFReadStreamRef requestStream = CFReadStreamCreateForHTTPRequest(NULL, request); CFReadStreamOpen(requestStream); NSMutableData *responseBytes = [NSMutableData data]; CFIndex numBytesRead = 0 ; NSUInteger totalBytesRead = 0; ! do { UInt8 buf[1024]; numBytesRead = CFReadStreamRead(requestStream, buf, sizeof(buf)); if(numBytesRead > 0) { [responseBytes appendBytes:buf length:numBytesRead]; totalBytesRead += numBytesRead; } } while(numBytesRead > 0); if (totalBytesRead > 0) { CFHTTPMessageRef response = (CFHTTPMessageRef)CFReadStreamCopyProperty(requestStream, kCFStreamPropertyHTTPResponseHeader); CFHTTPMessageSetBody(response, (__bridge CFDataRef)responseBytes); CFReadStreamClose(requestStream); CFDataRef responseBodyData = CFHTTPMessageCopyBody(response); NSError *error = nil; NSDictionary *jsonData = [NSJSONSerialization JSONObjectWithData:(__bridge NSData *)responseBodyData options:0 error:&error]; CFRelease(responseBodyData); CFRelease(response); if (!jsonData) { UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Error" message:@"The data was corrupt. Sorry" delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil]; [alert show]; } else { NSString *ip = jsonData[@"ip"]; UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Success!" message:[NSString stringWithFormat:@"Your IP is: %@", ip] delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil]; [alert show]; } } else { UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Error" message:@"There was an error getting the data. Please try again later." delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil]; [alert show]; } ! CFRelease(requestStream); CFRelease(request);

• All this code, just to download and display this:

{"ip": "72.191.49.142"}

• Plus we have to write gross C with nasty CFRelease()

AFNetworking

“AFNetworking is a delightful networking library for iOS and Mac OS X. It's built on top of the Foundation URL Loading System, extending the powerful high-level networking abstractions built into Cocoa. It has a modular architecture with well-designed, feature-rich APIs that are a joy to use.”

AFNetworking

NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:DOWNLOAD_URL]]; !AFHTTPRequestOperation *operation = [[AFHTTPRequestOperation alloc] initWithRequest:request]; [operation setResponseSerializer:[AFJSONResponseSerializer serializer]]; [operation setCompletionBlockWithSuccess:successHandler failure:failureHandler]; ![operation start];

AFNetworking

void(^failureHandler)(AFHTTPRequestOperation *, NSError *) = ^(AFHTTPRequestOperation *operation, NSError *error) { UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Error" message:@"There was an error getting the data. Please try again later." delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil]; [alert show]; };

AFNetworking

void(^successHandler)(AFHTTPRequestOperation *, id) = ^(AFHTTPRequestOperation *operation, id responseObject) { if (!responseObject) { failureHandler(operation, [NSError errorWithDomain:AFNetworkingErrorDomain code:404 userInfo:nil]); } else { NSString *ip = responseObject[@"ip"]; ! UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Success!" message:[NSString stringWithFormat:@"Your IP is: %@", ip] delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil]; [alert show]; } };

void(^failureHandler)(AFHTTPRequestOperation *, NSError *) = ^(AFHTTPRequestOperation *operation, NSError *error) { UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Error" message:@"There was an error getting the data. Please try again later." delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil]; [alert show]; }; void(^successHandler)(AFHTTPRequestOperation *, id) = ^(AFHTTPRequestOperation *operation, id responseObject) { if (!responseObject) { failureHandler(operation, [NSError errorWithDomain:AFNetworkingErrorDomain code:404 userInfo:nil]); } else { NSString *ip = responseObject[@"ip"]; ! UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Success!" message:[NSString stringWithFormat:@"Your IP is: %@", ip] delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil]; [alert show]; } }; NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:DOWNLOAD_URL]]; AFHTTPRequestOperation *operation = [[AFHTTPRequestOperation alloc] initWithRequest:request]; [operation setResponseSerializer:[AFJSONResponseSerializer serializer]]; [operation setCompletionBlockWithSuccess:successHandler failure:failureHandler]; ![operation start];

- (IBAction)didSelectRefreshButton:(id)sender { NSURL *url = [NSURL URLWithString:@"http://ip.jsontest.com/"]; NSURLRequest *request = [NSURLRequest requestWithURL:url]; ! self.connection = [[NSURLConnection alloc] initWithRequest:request delegate:self startImmediately:YES]; } !#pragma mark - NSURLConnection !- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSHTTPURLResponse *)response { _data = nil; ! switch (response.statusCode) { case 200: { self.data = [NSMutableData dataWithCapacity:(NSUInteger)response.expectedContentLength]; } break; default: { [connection cancel]; ! NSError *error = [NSError errorWithDomain:(NSString *)kCFErrorDomainCFNetwork code:response.statusCode userInfo:@{(NSString *)kCFErrorDescriptionKey : (NSString *)kCFURLErrorFailingURLErrorKey}]; [self connection:connection didFailWithError:error]; } break; } } !- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data { [self.data appendData:data]; } !- (void)connectionDidFinishLoading:(NSURLConnection *)connection { NSError *error = nil; NSDictionary *jsonData = [NSJSONSerialization JSONObjectWithData:self.data options:0 error:&error]; if (!jsonData) { UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Error" message:@"The data was corrupt. Sorry" delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil]; [alert show]; } else { NSString *ip = jsonData[@"ip"]; UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Success!" message:[NSString stringWithFormat:@"Your IP is: %@", ip] delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil]; [alert show]; } ! self.connection = nil; } !- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error { UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Error" message:@"There was an error getting the data. Please try again later." delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil]; [alert show]; self.connection = nil; }

Key Concepts

• AF*Operation are subclasses of NSOperation

• Networking operations can be started individually or placed in an NSOperationQueue

• Custom serialization classes can be created for transforming and validating data.

Demo: Using Queues

AFURLResponseSerializer

• If you don’t specify a request/response serializer, it will give back NSData.

• Serializers can be created to handle data transformation and validation.

AFURLResponseSerializerAFJSONResponseSerializer

AFPropertyListResponseSerializer

AFImageResponseSerializer

AFCompoundResponseSerializer

AFXMLParserResponseSerializer

!

AFXMLDocumentResponseSerializer

Custom Serializer

• Subclass AFHTTPResponseSerializer

• Override

• responseObjectForResponse:data:error:

• acceptableContentTypes

Custom Serializer

• We’re going to create a serializer for decoding 1337593@k

Anyone know the Content-Type for 1337 encoded data?

@99l1c@710n/l337

D3m0: Cu570m R3590n53 53r1@l1z@710n

AFNetworking + UIKit• AFNetworking adds a number of extensions to common UIKit

classes:

• UIImageView

• UIButton

• UIWebView

• UIProgressView

• UIRefreshControl

Demo: UIKit Extensions

Design Patterns for Network & Data

“At its heart, programming is all about abstraction.”

Justin Spahr-Summers CocoaConf Austin 2014

Classes should have as few purposes as possible (say, one) and do it very well. !

Classes should know as little as possible about other classes.

Are your View Controllers like this?

Case Study:

Geekdom for iOS

Monster View Controller• UITableView Datasource • Configure Cells • UITableView Delegate • Showing Member Details • NSFetchedResultsControllerDelegate • Fetch All Member data • Fetch Checked-In Members • Fetch Profile Images • Search Members By Name • Search Members By Skills • Data Persistance • Check-In logic • Checked-In vs All Members

Questions?

@waynehartman