working with afnetworking
Post on 27-Jan-2015
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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
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