I am stuck in serially Execution of Afnetworking Operation. Currently I am able to get all the operations' response but those are not serially . I need to make it serial.
What I am doing is
for (int i = 0; i < myArray.count; i++) {
//Creating Soap Request
// Adding that SoapRequest to Operation
AFHTTPRequestOperation *operation = [[AFHTTPRequestOperation alloc] initWithRequest:request];
[operation setCompletionBlockWithSuccess:^(AFHTTPRequestOperation *operation, id responseObject) {
// On success I am parsing the response
// Parsing is executed here..
} failure:^(AFHTTPRequestOperation *operation, NSError *error) {
// Failure message
}
// If Network is reachable then adding the Operation in queue
[[PFAPIClient sharedClient] enqueueHTTPRequestOperation:operation];
// Adding the operation (For multiple execution of operations)
}
Thus the response I get is not serial . Please Help me out.
So How to get this response serially and parsing the response accordingly .. After successfully Parsing I have to display them..
You can either set maxConcurrentOperationCount of PFAPIClient's NSOperationQueue to 1 or you can use dependencies, e.g.:
AFHTTPRequestOperation *previousOperation = nil;
for (int i = 0; i < myArray.count; i++) {
AFHTTPRequestOperation *operation = [[AFHTTPRequestOperation alloc] initWithRequest:request];
[operation setCompletionBlockWithSuccess:... failure:...];
if (previousOperation) {
[operation addDependency:previousOperation];
}
[[PFAPIClient sharedClient] enqueueHTTPRequestOperation:operation];
previousOperation = operation;
}
It's too bad you have to do these sequentially, as you'll pay huge performance penalty, but if you have to do it, that's two ways to accomplish it.
Related
I'm using AFNetworking to download more or less 200 images. The problem is that the main thread is blocked during the download, not during the success/failure block.
Here is my code:
imageDownloads=[[NSMutableArray alloc]init];
for(NSString *url in liens){
NSString *totalURL = [NSString stringWithFormat:#"http://%#", url];
[imageDownloads addObject:[[ImageDownload alloc] initWithURL:[NSURL URLWithString:totalURL] filename:nil]];
}
for (int i=0; i < imageDownloads.count; i++)
{
ImageDownload *imageDownload = imageDownloads[i];
[self downloadImageFromURL:imageDownload];
}
- (void)downloadImageFromURL:(ImageDownload *)imageDownload
{
NSURLRequest *request = [NSURLRequest requestWithURL:imageDownload.url];
AFHTTPRequestOperation *operation = [[AFHTTPRequestOperation alloc] initWithRequest:request];
[operation setDownloadProgressBlock:^(NSUInteger bytesRead, long long totalBytesRead, long long totalBytesExpectedToRead) {
imageDownload.totalBytesRead = totalBytesRead;
imageDownload.totalBytesExpected = totalBytesExpectedToRead;
[self updateProgressView];
}];
[operation setCompletionBlockWithSuccess:^(AFHTTPRequestOperation *operation, id responseObject) {
NSAssert([responseObject isKindOfClass:[NSData class]], #"expected NSData");
imageDownload.totalBytesExpected = imageDownload.totalBytesRead;
[self updateProgressView];
//all kind of basic stuff here I left out: I get store the data inside CoreData
NSLog(#"finished %#", imageDownload);
} failure:^(AFHTTPRequestOperation *operation, NSError *error) {
NSLog(#"error %#", error);
}];
[operation start];
}
Basically, when I launch the code, the thread is blocked for like 30-40 seconds (the pictures are about 100MB in total), and then suddenly I can see all the NSLog logs appear with the "Finished"... text. So that part if really quick. But I thought AFNetworking wasn't supposed to block the main thread while I was downloading? This also doesn't allow me to track the progress of the download...Am I doing something wrong or misinterpreting something?
You're updating the progress view in the progress block. Because AFNetworking is inherently async anyway, each of these requests will stack and run at the same time. If you're running 200 of them, that's going to freeze up the app. Try using NSOperationQueue's maxConcurrentOperationCount to limit the number of concurrent threads.
Alternatively, you could save all the trouble and just use sdwebimage.
I tried to use afnetworking for a simple testing, but it seemed that the success/failure blcok was not triggered at all, is there anything I forgot to set up?
My code is below:
int main(int argc, const char * argv[]) {
#autoreleasepool {
NSString *string = [NSString stringWithFormat:#"%#weather.php?format=json", BaseURLString];
NSURL *url = [NSURL URLWithString:string];
NSURLRequest *request = [NSURLRequest requestWithURL:url];
AFHTTPRequestOperation *operation = [[AFHTTPRequestOperation alloc] initWithRequest:request];
operation.responseSerializer = [AFJSONResponseSerializer serializer];
[operation setCompletionBlockWithSuccess:^(AFHTTPRequestOperation *operation, id responseObject) {
NSLog(#"Succeed!");
} failure:^(AFHTTPRequestOperation *operation, NSError *error) {
NSLog(#"Fail");
}];
[operation start];
}
return 0;
}
Updated: I tried use a loop a to wait the operation to execute and print out, but nothing was printed out. Here is my updated version
int main(int argc, const char * argv[]) {
#autoreleasepool {
__block bool result = false;
NSString *string = [NSString stringWithFormat:#"%#weather.php?format=json", BaseURLString];
NSURL *url = [NSURL URLWithString:string];
NSURLRequest *request = [NSURLRequest requestWithURL:url];
AFHTTPRequestOperation *operation = [[AFHTTPRequestOperation alloc] initWithRequest:request];
operation.responseSerializer = [AFJSONResponseSerializer serializer];
[operation setCompletionBlockWithSuccess:^(AFHTTPRequestOperation *operation, id responseObject) {
NSLog(#"Succeed!");
result = true;
} failure:^(AFHTTPRequestOperation *operation, NSError *error) {
NSLog(#"Fail");
result = true;
}];
[operation start];
while (1) {
if (result) {
break;
}
}
}
return 0;
}
Yes they will not be called because the program exits out before the operation even starts.
The main function returns 0 and the program ends and the operation have still not started.
You need to read more on asynchronous blocks.
A common and simple approach to solve this problem (having an async function and a continuation) in a console test app would leveraging a semaphore which you wait on in the main function before you exit and release it in the continuation, which runs on some other thread. Now, the main thread will be blocked when waiting on the semaphore up until the semaphore gets released when the continuation has been run. Quite simple.
If you want to try out AFN in an console application, however, this does not work. You need to use a run loop which adds some undesired complexity in order to get this simple test app to run. This is unfortunate, and stems from the simple fact that AFN executes its continuations on the main thread. IMHO, this is is a very bad design decision, which can lead to dead locks (as it would happen in your case) and is also less efficient.
So, your approach would use a RunLoop where you basically loop and check a flag for the condition "done" which is set by the continuation (the completion blocks). Since you are reading an writing the flag on the main thread only, you don't get a data race - that is, it should be thread safe.
I'm trying to figure out a way to download multiple images with AFNewtorking 2.0. I've read a lot of posts here in SO, but can't find the answer I'm looking for, hope you guys can help me.
The problem is that I want to know when all of the downloads finished and if all images where downloaded.
So I have an array with image URL's ant trying to do something like this.
for(NSString *photoUrlString in self.photos){
NSURL *url = [NSURL URLWithString:photoUrlString];
AFHTTPRequestOperation *requestOperation = [[AFHTTPRequestOperation alloc] initWithRequest:[NSURLRequest requestWithURL:url]];
requestOperation.responseSerializer = [AFImageResponseSerializer serializer];
[requestOperation setCompletionBlockWithSuccess:^(AFHTTPRequestOperation *operation, id responseObject) {
} failure:^(AFHTTPRequestOperation *operation, NSError *error) {
NSLog(#"Image error: %#", error);
}];
[requestOperation start];
}
I've found some answers with putting these requests into a queue and setting max concurrent operations to 1. But don't know how that works really.
Any help is appreciated, thanks in advance!
for(Photo *photo in array){
//form the path where you want to save your downloaded image to
NSString *constPath = [photo imageFullPath];
//url of your photo
NSURL *url = [NSURL URLWithString:photo.serverPath];
AFHTTPRequestOperation *op = [[AFHTTPRequestOperation alloc] initWithRequest:[NSURLRequest requestWithURL:url]];
op.responseSerializer = [AFImageResponseSerializer serializer];
op.outputStream = [NSOutputStream outputStreamToFileAtPath:constPath append:NO];
op.queuePriority = NSOperationQueuePriorityLow;
[op setDownloadProgressBlock:^(NSUInteger bytesRead, long long totalBytesRead, long long totalBytesExpectedToRead){
}];
op.completionBlock = ^{
//do whatever you want with the downloaded photo, it is stored in the path you create in constPath
};
[requestArray addObject:op];
}
NSArray *batches = [AFURLConnectionOperation batchOfRequestOperations:requestArray progressBlock:^(NSUInteger numberOfFinishedOperations, NSUInteger totalNumberOfOperations) {
} completionBlock:^(NSArray *operations) {
//after all operations are completed this block is called
if (successBlock)
successBlock();
}];
[[NSOperationQueue mainQueue] addOperations:batches waitUntilFinished:NO];
Try this:
// _group, _queue are iVar variable
dispatch_group_t *_group = dispatch_group_create();
dispatch_queue_t *_queue = dispatch_queue_create("com.company.myqueue2", NULL);
// all files download
for(int i = 0 ; i < numberOfFileDownloads; i++){
dispatch_group_async(_group, _queue, ^{
// here is background thread;
// download file
});
}
// all files are download successfully, this method is called
dispatch_group_notify(_group, _queue, ^{
}
Check out +[AFURLConnectionOperation batchOfRequestOperations:progressBlock:completionBlock:]
Although it's not documented, implementation is self-explanatory. Also it allows you to monitor the progress.
You will need to have an array of HTTP operations prior to using this method (this is if you decided to stick to NSURLConnection-based implementation of AFNetworking).
So I'm rewriting an app for iOS 7 with AFNetworking 2.0 and I'm running into the issue of sending a batch of requests at once and tracking their progress. In the old AFNetworking there was the enqueueBatchOfHTTPRequestOperations:progressBlock:completionBlock: method on AFHTTPClient, this is clearly refactored out and I'm a bit confused on how to enqueue multiple requests.
I have created a subclass of AFHTTPSessionManager and I'm using the POST:... and GET:... methods to communicate with the server. But I can't find anything in the code and/or docs to enqueue multiple requests at once like with the old AFHTTPClient.
The only thing I can find is the undocumented batchOfRequestOperations:progressBlock:completionBlock: method on AFURLConnectionOperation, but that looks like the iOS 6 way of doing this.
Clearly I'm missing something in the new NSURLSession concept that I should use to batch requests or looking over a new AFNetworking feature. Hope someone can help me on the right track here!
tl;dr: How can I send a batch of requests with my AFHTTPSessionManager subclass?
Thanks Sendoa for the link to the GitHub issue where Mattt explains why this functionality is not working anymore. There is a clear reason why this isn't possible with the new NSURLSession structure; Tasks just aren't operations, so the old way of using dependencies or batches of operations won't work.
I've created this solution using a dispatch_group that makes it possible to batch requests using NSURLSession, here is the (pseudo-)code:
// Create a dispatch group
dispatch_group_t group = dispatch_group_create();
for (int i = 0; i < 10; i++) {
// Enter the group for each request we create
dispatch_group_enter(group);
// Fire the request
[self GET:#"endpoint.json"
parameters:nil
success:^(NSURLSessionDataTask *task, id responseObject) {
// Leave the group as soon as the request succeeded
dispatch_group_leave(group);
}
failure:^(NSURLSessionDataTask *task, NSError *error) {
// Leave the group as soon as the request failed
dispatch_group_leave(group);
}];
}
// Here we wait for all the requests to finish
dispatch_group_notify(group, dispatch_get_main_queue(), ^{
// Do whatever you need to do when all requests are finished
});
I want to look write something that makes this easier to do and discuss with Matt if this is something (when implemented nicely) that could be merged into AFNetworking. In my opinion it would be great to do something like this with the library itself. But I have to check when I have some spare time for that.
Just updating the thread... I had the same problem and after some researches I found some good solutions, but I decided to stick with this one:
I am using the project called Bolts. So, for the same sample above posted by #Mac_Cain13, it would be:
[[BFTask taskWithResult:nil] continueWithBlock:^id(BFTask *task) {
BFTask *task = [BFTask taskWithResult:nil];
for (int i = 0; i < 10; i++) {
task = [task continueWithBlock:^id(BFTask *task) {
return [self executeEndPointAsync];
}];
}
return task;
}] continueWithBlock:^id(BFTask *task) {
// Everything was executed.
return nil;
}];;
- (BFTask *) executeEndPointAsync {
BFTaskCompletionSource *task = [BFTaskCompletionSource taskCompletionSource];
[self GET:#"endpoint.json" parameters:nil
success:^(NSURLSessionDataTask *task, id responseObject) {
[task setResult:responseObject];
}
failure:^(NSURLSessionDataTask *task, NSError *error) {
[task setError:error];
}];
}];
return task.task;
}
Basically, it's stacking all of the tasks, waiting and unwrapping until there is no more tasks, and after everything is completed the last completion block is executed.
Another project that does the same thing is RXPromise, but for me the code in Bolts was more clear.
For request which can be post or get, you can use AFNetworking 2.0 for batch operation as firstly you need to create operation like this:
//Request 1
NSString *strURL = [NSString stringWithFormat:#"your url here"];
NSLog(#"scheduleurl : %#",strURL);
NSDictionary *dictParameters = your parameters here
NSMutableURLRequest *request = [[AFHTTPRequestSerializer serializer] requestWithMethod:#"POST" URLString:strURL parameters:dictParameters error: nil];
AFHTTPRequestOperation *operationOne = [[AFHTTPRequestOperation alloc] initWithRequest:request];
operationOne = [AFHTTPResponseSerializer serializer];
[operationOne setCompletionBlockWithSuccess:^(AFHTTPRequestOperation *operation, id responseObject)
{
//do something on completion
}
failure:^(AFHTTPRequestOperation *operation, NSError *error)
{
NSLog(#"%#",[error description]);
}];
//Request 2
NSString *strURL1 = [NSString stringWithFormat:#"your url here"];
NSLog(#"scheduleurl : %#",strURL);
NSDictionary *dictParameters1 = your parameters here
NSMutableURLRequest *request1 = [[AFHTTPRequestSerializer serializer] requestWithMethod:#"POST" URLString:strURL1 parameters:dictParameters1 error: nil];
AFHTTPRequestOperation *operationTwo = [[AFHTTPRequestOperation alloc] initWithRequest:request1];
operationTwo = [AFHTTPResponseSerializer serializer];
[operationTwo setCompletionBlockWithSuccess:^(AFHTTPRequestOperation *operation, id responseObject)
{
//do something on completion
}
failure:^(AFHTTPRequestOperation *operation, NSError *error)
{
NSLog(#"%#",[error description]);
}];
//Request more here if any
Now perform batch operation like this :
//Batch operation
//Add all operation here
NSArray *operations = [AFURLConnectionOperation batchOfRequestOperations:#[operationOne,operationTwo] progressBlock:^(NSUInteger numberOfFinishedOperations, NSUInteger totalNumberOfOperations)
{
NSLog(#"%i of %i complete",numberOfFinishedOperations,totalNumberOfOperations);
//set progress here
yourProgressView.progress = (float)numberOfFinishedOperations/(float)totalNumberOfOperations;
} completionBlock:^(NSArray *operations)
{
NSLog(#"All operations in batch complete");
}];
[[NSOperationQueue mainQueue] addOperations:operations waitUntilFinished:NO];
On AFNetworking 2.0, AFHTTPClient has been split on AFHTTPRequestOperationManager and AFHTTPSessionManager, so probably you could start with the first, which has operationQueue property.
Currently, NSURLSession tasks are not suitable for the same kind of patterns request operations use. See the answer from Mattt Thompson here regarding this issue.
Direct answer: if you need dependencies or batches, you'll still need to use request operations.
I download asynchronously some object, I store it in array. Next for each object I download some coordinates with geocoding (it is also asynchronously), and update my database for each object with new parameters which is coordinate. My method looks like this:
- (void)downloadObjectsWithTitle:(NSString *)title andHandler:(void(^)(NSMutableDictionary *result))handler {
AFHTTPClient *httpClient = [[AFHTTPClient alloc] initWithBaseURL:url];
NSMutableURLRequest *request = [httpClient requestWithMethod:#"GET"
path:nil
parameters:nil];
AFHTTPRequestOperation *operation = [[AFHTTPRequestOperation alloc] initWithRequest:request];
[httpClient registerHTTPOperationClass:[AFHTTPRequestOperation class]];
[operation setCompletionBlockWithSuccess:^(AFHTTPRequestOperation *operation, id responseObject) {
//I get here array of objects
//now for each object I want to download geocoding localization so i called another asynchronyous method getLocationWithTitle:andHandler;
for(int i = 0; i < resutArray.count; i++) {
[self downloadLocationWithString:[dictionary objectForKey:#"string"] andHandler:^(NSMutableDictionary *result) {
//update database;
}];
}
handler(dictionary);
} failure:^(AFHTTPRequestOperation *operation, NSError *error) {
NSLog(#"Error: %#", error);
}];
[operation start];
}
My question is how to downalod coordinates for each object and that fire:
handler(dictionary);
so wait for each coordinates download (for each object) before quit method (fire handler).
Thnaks for all sugestions.
Maintain a count of all the tasks. When it's zero you're done.
Assuming you're using dispatch_async in downloadLocationWithString: on a concurrent queue:
dispatch_barrier_async(queue, ^{
// will only be called after all the blocks submitted to queue have finished.
}];
(If you're using serial queue, simply call handler at the last line of the last block)
Try a global flag. set NO first. In download block, after download complete set flag to yes. You can check that flag.