TRVSURLSessionOperation

NSURLSession and NSOperationQueue working together

TRVSURLSessionOperation is an NSOperation subclass that wraps NSURLSessionTask so you can use them in a NSOperationQueue.

With this you can:

Schedule network requests (i.e. run request A then request B, and give requests priority)
Limit the number of concurrent network requests (e.g. have 5 network requests running at any given time)
Control these network operations the same as other NSOperation objects (e.g. you have an NSOperation that creates an image, then an TRVSURLSessionOperation that uploads that image to a web service)

Usage

NSOperationQueue *queue = [[NSOperationQueue alloc] init];
NSURLSession *session = [NSURLSession sessionWithConfiguration:[NSURLSessionConfiguration defaultSessionConfiguration]];

[queue addOperation:[[TRVSURLSessionOperation alloc] initWithSession:session request:[NSURLRequest requestWithURL:@"https://twitter.com/travisjeffery"] completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) { ... }]];

Run a request on the completion of another, specific request

For example, you have an initial request to log a user in or fetch their settings, and you want subsequent requests to wait for that initial request to finish and then they run.

NSOperationQueue *queue = [[NSOperationQueue alloc] init];
NSURLSession *session = [NSURLSession sessionWithConfiguration:[NSURLSessionConfiguration defaultSessionConfiguration]];

TRVSURLSessionOperation *settingsOperation = [[TRVSURLSessionOperation alloc] initWithSession:session request:[NSURLRequest requestWithURL:@"..."] completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) { ... }];

TRVSURLSessionOperation *anotherOperation = [[TRVSURLSessionOperation alloc] initWithSession:session request:[NSURLRequest requestWithURL:@"..."] completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) { ... }];

// get some settings for your app from your server, and queue subsequent requests that depend on those settings.
[anotherOperation addDependency:settingsOperation];

[queue addOperations:@[ loginOperation, settingsOperation ] waitUntilAllOperationsAreFinished:NO];

Pause and resume/suspend requests from executing

NSOperationQueue *queue = [[NSOperation alloc] init];
queue.suspended = YES;

// these request/operations won't run
[queue addOperation:[[TRVSURLSessionOperation alloc] initWithSession:session request:[NSURLRequest requestWithURL:@"https://twitter.com/travisjeffery"] completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) { ... }]];

[queue addOperation:[[TRVSURLSessionOperation alloc] initWithSession:session request:[NSURLRequest requestWithURL:@"https://github.com/travisjeffery"] completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) { ... }]];

queue.suspended = NO;
// until now

Limit the number of concurrent requests

NSOperationQueue *queue = [[NSOperationQueue alloc] init];
queue.maxConcurrentOperationCount = 1; // only one request will run at once

NSURLSession *session = [NSURLSession sessionWithConfiguration:[NSURLSessionConfiguration defaultSessionConfiguration]];

[queue addOperation:[[TRVSURLSessionOperation alloc] initWithSession:session request:[NSURLRequest requestWithURL:@"https://twitter.com/travisjeffery"] completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) { ... }]];

[queue addOperation:[[TRVSURLSessionOperation alloc] initWithSession:session request:[NSURLRequest requestWithURL:@"https://github.com/travisjeffery"] completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) { ... }]];

Wait until all requests are finished

NSOperationQueue *queue = [[NSOperationQueue alloc] init];

NSURLSession *session = [NSURLSession sessionWithConfiguration:[NSURLSessionConfiguration defaultSessionConfiguration]];

[queue addOperation:[[TRVSURLSessionOperation alloc] initWithSession:session request:[NSURLRequest requestWithURL:@"https://twitter.com/travisjeffery"] completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) { ... }]];

[queue addOperation:[[TRVSURLSessionOperation alloc] initWithSession:session request:[NSURLRequest requestWithURL:@"https://github.com/travisjeffery"] completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) { ... }]];

[queue waitUntilAllOperationsAreFinished];

NSLog(@"All requests are done!");

Install

Use CocoaPods, and put the following in your Podfile:

pod 'TRVSURLSessionOperation', '~> 0.0.1'

Or manually drag the TRVSURLSessionOperation folder into your Xcode project.

travisjeffery/TRVSURLSessionOperation