Learn to love networking on iOS

Paolo Tagliani § Learn to love networking on iOS

Learn to love networking on iOS


#pragma me

• Paolo Tagliani (@PablosProject)

• iOS Developer @Superpartes Innovation Campus

• Founder of #pragma mark

• various stuff…

!

• @PablosProject

• http://www.pablosproject.com

• https://www.facebook.com/paolo.tagliani

• https://github.com/pablosproject

• More…

https://www.facebook.com/paolo.tagliani

https://github.com/pablosproject


What you need to know

HTTP Basics



HTTP Basics

HTTP Verbs • GET • POST • PUT • DELETE • HEAD • …

HTTP Response code • 2xx (success) • 4xx (client error) • 5xx (server error) • 1xx (informational) • 3xx (redirection)



HTTP Basics

http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html

http://en.wikipedia.org/wiki/Hypertext_Transfer_Protocol



• Client-server

• Cachable

• Stateless

• Layered



• Client-server

• Cachable

• Stateless

• Layered

http://en.wikipedia.org/wiki/Representational_state_transfer

http://en.wikipedia.org/wiki/Representational_state_transfer

Learn to love networking




Objective-C



Objective-C

iOS Bootcamp


iOS Bootcamp


iOS Bootcamp



Networking in cocoa

Foundation (NSURL* classes)

CFNetwork

BSD Socket


Networking in cocoa


CFNetwork

BSD Socket


Networking in cocoa


CFNetwork

BSD Socket

https://www.freebsd.org/doc/en/books/developers-handbook/sockets.html

iOS Bootcamp

Networking in Cocoa: CFNetworkFoundation (NSURL* classes)

CFNetwork

BSD Socket

CFNetwork is a low-level, high-performance framework that gives you the ability to have detailed control over the protocol stack. It is an extension to BSD sockets, the standard socket abstraction API that provides objects to simplify tasks such as communicating with FTP and HTTP servers or resolving DNS hosts. CFNetwork is based, both physically and theoretically, on BSD sockets. (https://developer.apple.com/library/ios/

documentation/Networking/Conceptual/CFNetwork/Introduction/Introduction.html#//apple_ref/doc/uid/TP30001132)

Definition

https://developer.apple.com/library/ios/documentation/Networking/Conceptual/CFNetwork/Introduction/Introduction.html#//apple_ref/doc/uid/TP30001132

iOS Bootcamp


CFNetwork

BSD Socket

Definition

iOS Bootcamp


CFNetwork

BSD Socket • Only C code

Definition

iOS Bootcamp


CFNetwork


• Focused on network protocol (HTTP and FTP)

Definition

iOS Bootcamp


CFNetwork



• Abstractions : streams and socket

Definition

iOS Bootcamp


CFNetwork



• Abstractions : streams and socket

Definition

iOS Bootcamp


CFNetwork

BSD Socket

CFStringRef url = CFSTR("http://www.apple.com"); !CFURLRef myURL = CFURLCreateWithString(kCFAllocatorDefault, url, NULL); !CFStringRef requestMethod = CFSTR("GET"); ! !CFHTTPMessageRef myRequest = CFHTTPMessageCreateRequest(kCFAllocatorDefault, ! requestMethod, myUrl, kCFHTTPVersion1_1); !CFHTTPMessageSetBody(myRequest, bodyData); !CFHTTPMessageSetHeaderFieldValue(myRequest, headerField, value); ! !CFReadStreamRef myReadStream = CFReadStreamCreateForHTTPRequest(kCFAllocatorDefault, myRequest); ! !CFReadStreamOpen(myReadStream);

Example: communicate with HTTP server

iOS Bootcamp


CFNetwork

BSD Socket

Example: communicate with HTTP server

//Setting the client for the stream Boolean CFReadStreamSetClient ( CFReadStreamRef stream, CFOptionFlags streamEvents, CFReadStreamClientCallBack clientCB, CFStreamClientContext *clientContext ); !//Callback to handle stream Events !void myCallBack (CFReadStreamRef stream, CFStreamEventType event, void *myPtr) { switch(event) { case kCFStreamEventHasBytesAvailable: {…} break; case kCFStreamEventErrorOccurred: {…} break; case kCFStreamEventEndEncountered: {…} break; } }

iOS Bootcamp


CFNetwork

BSD Socket

Summary

iOS Bootcamp


CFNetwork

BSD Socket

• CFNetwork is a low-level C API that provides abstractions over BSD sockets

Summary

iOS Bootcamp


CFNetwork

BSD Socket


• Provide high flexibility

Summary

iOS Bootcamp


CFNetwork

BSD Socket



• As you write your code, it is recommended that you prefer the use of higher-level frameworks over lower-level frameworks whenever possible.

Summary

iOS Bootcamp


CFNetwork

BSD Socket



• As you write your code, it is recommended that you prefer the use of higher-level frameworks over lower-level frameworks whenever possible.

Summary


Networking in cocoa : FoundationFoundation (NSURL* classes)

CFNetwork

BSD Socket

URL loading system



CFNetwork

BSD Socket • Set of API written in Objective-C

URL loading system



CFNetwork


• High level abstraction for interaction with URL resources

URL loading system



CFNetwork



• At the heart of this technology is the NSURL class, which lets your app manipulate URLs and the resources they refer to.

URL loading system



CFNetwork



• At the heart of this technology is the NSURL class, which lets your app manipulate URLs and the resources they refer to.

• Together these classes (NSURL*) are referred to as the URL loading system.

URL loading system



CFNetwork

BSD Socket

URL loading system



CFNetwork

BSD Socket

URL loading system


Networking in cocoa : Foundation

NSURLConnection or NSURLSession?Foundation (NSURL* classes)

CFNetwork

BSD Socket




CFNetwork

BSD Socket




CFNetwork

BSD Socket


Networking in cocoa : FoundationNSURLConnectionFoundation (NSURL* classes)

CFNetwork

BSD Socket



CFNetwork

BSD Socket • Use 2 different support classes: NSURLRequest and NSURLResponse.



CFNetwork


• Most of the setup is made on NSURLRequest. It manages:



CFNetwork



• The request URL



CFNetwork



• The request URL

• Cache policy



CFNetwork



• The request URL

• Cache policy

• HTTP Parameters and header fiels



CFNetwork



• The request URL

• Cache policy


• Timeout



CFNetwork



• The request URL

• Cache policy


• Timeout



CFNetwork



• The request URL

• Cache policy


• Timeout

• NSURLResponse manage the response information (ex. HTTP status code)



NSURLConnectionFoundation (NSURL* classes)

CFNetwork

BSD Socket




CFNetwork

BSD Socket • Most flexible method for retrieving content of URL.




CFNetwork


• Use three different ways for retrieving the content:




CFNetwork



• Synchronous call




CFNetwork




• Asynchronous with delegate




CFNetwork




• Asynchronous with delegate

• Asynchronous with block



CFNetwork

BSD Socket

Synchronous connection

// Create the request. NSURLRequest *theRequest=[NSURLRequest requestWithURL:[NSURL URLWithString:@"http://www.apple.com/"] cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:60.0]; !//Create a response for the request NSURLResponse *response; !NSError *error; !//Send the request [NSURLConnection sendSynchronousRequest:request returningResponse:&response error:&error];



CFNetwork

BSD Socket





CFNetwork

BSD Socket





CFNetwork

BSD Socket

Asynchronous connection with delegate: create the request

// Create the request. NSURLRequest *theRequest=[NSURLRequest requestWithURL:[NSURL URLWithString:@"http://www.apple.com/"] cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:60.0]; // Create the NSMutableData to hold the received data. // receivedData is an instance variable declared elsewhere. receivedData = [NSMutableData dataWithCapacity: 0]; // create the connection with the request // and start loading the data NSURLConnection *theConnection=[[NSURLConnection alloc] initWithRequest:theRequest delegate:self];



CFNetwork

BSD Socket

Asynchronous connection with delegate: handle request event! - (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response { // This method is called when the server has determined that it // has enough information to create the NSURLResponse object. // receivedData is an instance variable declared elsewhere. [receivedData setLength:0]; } ... - (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data { // Append the new data to receivedData. // receivedData is an instance variable declared elsewhere. [receivedData appendData:data]; } ... - (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error { //Clean all variables theConnection = nil; receivedData = nil; // inform the user NSLog(@"Connection failed! Error - %@ %@", [error localizedDescription], [[error userInfo] objectForKey:NSURLErrorFailingURLStringErrorKey]); }



CFNetwork

BSD Socket

Asynchronous connection with delegate: handle request event



CFNetwork

BSD Socket

Asynchronous connection with delegate: handle request event

NSURLConnectionDelegate (https://developer.apple.com/library/ios/documentation/Foundation/Reference/NSURLConnectionDelegate_Protocol/Reference/

Reference.html) !!

NSURLConnectionDataDelegate (https://developer.apple.com/library/ios/DOCUMENTATION/Foundation/Reference/NSURLConnectionDataDelegate_protocol/

Reference/Reference.html#//apple_ref/occ/intf/NSURLConnectionDataDelegate)

!

NSURLConnectionDownloadDelegate (https://developer.apple.com/library/ios/DOCUMENTATION/Foundation/Reference/NSURLConnectionDownloadDelegate_Protocol/

NSURLConnectionDownloadDelegate/NSURLConnectionDownloadDelegate.html#//apple_ref/occ/intf/NSURLConnectionDownloadDelegate)

https://developer.apple.com/library/ios/DOCUMENTATION/Foundation/Reference/NSURLConnectionDownloadDelegate_Protocol/NSURLConnectionDownloadDelegate/NSURLConnectionDownloadDelegate.html#//apple_ref/occ/intf/NSURLConnectionDownloadDelegate



CFNetwork

BSD Socket

Asynchronous connection with completion block

// Create the request. NSURLRequest *theRequest=[NSURLRequest requestWithURL:[NSURL URLWithString:@"http://www.apple.com/"] cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:60.0]; //Init an operation queue on which run the completion handler NSOperationQueue *queue = [[NSOperationQueue alloc] init]; [NSURLConnection sendAsynchronousRequest:request queue:queue completionHandler:^(NSURLResponse *response, NSData *data, NSError *connectionError) { //Handle error or return data }]



CFNetwork

BSD Socket

Asynchronous connection with completion block

// Create the request. NSURLRequest *theRequest=[NSURLRequest requestWithURL:[NSURL URLWithString:@"http://www.apple.com/"] cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:60.0]; //Init an operation queue on which run the completion handler NSOperationQueue *queue = [[NSOperationQueue alloc] init]; [NSURLConnection sendAsynchronousRequest:request queue:queue completionHandler:^(NSURLResponse *response, NSData *data, NSError *connectionError) { //Handle error or return data }]

Only for iOS 5.0+ Difficult to handle authentication Less flexibility


Networking in cocoa : FoundationNSURLSessionFoundation (NSURL* classes)

CFNetwork

BSD Socket



CFNetwork

BSD Socket

• The NSURLSession class and related classes provide an API for downloading content via HTTP.



CFNetwork

BSD Socket


• Work transparently with delegate and with completion callbacks (blocks).



CFNetwork

BSD Socket



• The NSURLSession API provides status and progress properties.



CFNetwork

BSD Socket



• The NSURLSession API provides status and progress properties.

• It supports canceling, restarting (resuming), and suspending tasks, and it provides the ability to resume suspended, canceled, or failed downloads.


Networking in cocoa : FoundationNSURLSession: types of sessionsFoundation (NSURL* classes)

CFNetwork

BSD Socket



CFNetwork

BSD Socket

• Default sessions use a persistent disk-based cache and store credentials in the user’s keychain.



CFNetwork

BSD Socket


• Ephemeral sessions do not store any data to disk; all caches, credential stores, and so on are kept in RAM and tied to the session.



CFNetwork

BSD Socket


• Ephemeral sessions do not store any data to disk; all caches, credential stores, and so on are kept in RAM and tied to the session.

• Background sessions are similar to default sessions, except that a separate process handles all data transfers.


Networking in cocoa : FoundationNSURLSession: taskFoundation (NSURL* classes)

CFNetwork

BSD Socket



CFNetwork

BSD Socket • Each session is composed by a number of task. A task is a simple HTTP network operation.



CFNetwork


• Different types of task:



CFNetwork



• Data tasks send and receive data using NSData objects. Data tasks are intended for short, often interactive requests from your app to a server.



CFNetwork




• Download tasks retrieve data in the form of a file, and support background downloads while the app is not running.



CFNetwork




• Download tasks retrieve data in the form of a file, and support background downloads while the app is not running.

• Upload tasks send data (usually in the form of a file), and support background uploads while the app is not running.



CFNetwork

BSD Socket

http://www.raywenderlich.com/51127/nsurlsession-tutorial


Networking in cocoa : FoundationWhy use NSURLSessionFoundation (NSURL* classes)

CFNetwork

BSD Socket



CFNetwork

BSD Socket • Background task: using this API the app creates automatically for you a daemon (on OSX) and wake up your app several time (on iOS) to complete background transfers.



CFNetwork


• Encapsulate network logic: each session manage its task. You can suspend, resume, and control progress of every task of the session.



CFNetwork



• Easy configuration: with NSURLSessionConfiguration: configure once and share configuration for all task.



CFNetwork



• Easy configuration: with NSURLSessionConfiguration: configure once and share configuration for all task.

• Uploads and downloads through the file system: This encourages the separation of the data (file contents) from the metadata (the URL and settings).


Networking in cocoa : FoundationSummaryFoundation (NSURL* classes)

CFNetwork

BSD Socket



CFNetwork

BSD Socket

You can do anything



CFNetwork

BSD Socket

You can do anything

BUT



CFNetwork

BSD Socket

You can do anything

BUT



CFNetwork

BSD Socket

You can do anything

BUT

•Build a network stack for your application can be difficult.



CFNetwork

BSD Socket

You can do anything

BUT




CFNetwork

BSD Socket

You can do anything

BUT


•There’s no a drop-in solution (i.e. reinvent the wheel every time)



CFNetwork

BSD Socket

You can do anything

BUT


•There’s no a drop-in solution (i.e. reinvent the wheel every time)


AFNetworking


AFNetworking

•11.00+ stars •3.000+ forks •1.500+ commits •1300+ closed issues •130 contributors


AFNetworking

@mattt

(Alamo Fire = AF*)


AFNetworking

AFNetworking 2.0• iOS 6+ & Mac OS X 10.8+

• Xcode 5

• NSURLSession & NSURLConnection

• Serialization Modules

• UIKit Extensions

• Real-time


AFNetworking

Structure

AFURLSessionTask

Download Upload Data

AFURLSessionManager

AFHTTPSessionManager

NSURLConnection

AFURLConnectionOperation

AFHTTPRequestOperation

AFHTTPRequestOperationManager


AFNetworking GET a resource

AFHTTPRequestOperationManager

- (AFHTTPRequestOperation *)GET:(NSString *)URLString parameters:(NSDictionary *)parameters success:(void ( ^ ) ( AFHTTPRequestOperation *operation , id responseObject ))success failure:(void ( ^ ) ( AFHTTPRequestOperation *operation , NSError *error ))failure;


AFNetworking GET a resource

- (NSURLSessionDataTask *)GET:(NSString *)URLString parameters:(NSDictionary *)parameters success:(void ( ^ ) ( NSURLSessionDataTask *task , id responseObject ))success failure:(void ( ^ ) ( NSURLSessionDataTask *task , NSError *error ))failure

AFHTTPSessionManager


AFNetworking Serialization

Request serializer Response serializer• HTTP • JSON • Property List

• HTTP • JSON • XML parser • XML document (OSX) • Property List • Image


AFNetworking Serializer extension

• MsgPack

• CSV / TSV

• vCard

• vCal

• WebP


AFNetworking Reachability

• Monitor reachability on:

• IP addresses

• URL

• Domain

• Support different type of connection

• 3G

• Wifi


AFNetworking UIKit extension

UIActivityIndicatorView

UIProgressView



UIRefreshControl

UIWebView



UIButton

UIImageView

Auto download

Caching

Operation management





[imageview setImgeWithURL:HearthImageURL]


AFNetworking Summary



• AFNetworking is powerful




• Lots of the common task already covered





• Drag’n drop solution





• Drag’n drop solution

DEMO TIME


Tools Charles web debugging proxy


Tools Postman REST client


Tools JSON Accelerator


Tools Cocoapods


References

• Apple documentation

• CFNetwork Programming guide

• URL Loading System Programming guide

!

• Ray Wanderlich

• AFNetworking 2.0 Tutorial

• NSURLSession Tutorial


References

• WWDC Video

• WWDC 2013 Session 705 “What’s New in Foundation Networking”

!

• NSScreencast

• Episode #91: AFNetworking2.0

• Episode #81: Networking in iOS 7

!

• NSHipster (@mattt)

• AFNetworking 2.0

• AFNetworking: the Definitive Guide (TBA)

iOS Bootcamp

@PablosProject http://pragmamark.org/

Learn to love networking on iOS

Engineering

instance variable declared

complete background transfers

synchronous call asynchronous

cfnetwork bsd socket

encapsulate network logic

related classes provide

app creates automatically

app manipulate urls