Easy to use CFNetwork wrapper for HTTP requests, Objective-C, Mac OS X and iPhone ASIHTTPRequest Documentation - All-Seeing Interactive an easy to use wrapper around cfnetwork http api, mac os x & iphone

AFNetworking : How to know if response is using cache or not ? 304 or 200

I can't find any answer to my question, may be I miss something...

When I ask for a url, I need to know if the response comes from the cache or from the net.

Is the status code 304 or 200 ? (but AFNetworking always responde 200)

With ASIHTTPRequest I used to check "didUseCachedResponse" from ASIHTTPRequest, this was perfect.

Source: (StackOverflow)

Objective-C: Instance Variable in Category

I am just asking whether it was possible to add an instance variable via a category. My special problem is, that I need to add an NSIndexPath property to an ASIHTTPRequest object but I don't wanna subclass the ASIHTTPRequest as a matter of principle.

Do I have any kind of alternative?

Thanks for your answers, Christian

Source: (StackOverflow)

ASIHTTPRequest set timeout

How can I set the session timeout using ASIHTTPRequest ?


Source: (StackOverflow)

Generic approach to NSManagedObjectContext in multi-threaded application

I've read a number of posts here about NSManagedObjectContext and multi-threaded applications. I've also gone over the CoreDataBooks example to understand how separate threads require their own NSManagedObjectContext, and how a save operation gets merged with the main NSManagedObjectContext. I found the example to be good, but also too application specific. I'm trying to generalize this, and wonder if my approach is sound.

My approach is to have a generic function for fetching the NSManagedObjectContext for the current thread. The function returns the NSManagedObjectContext for the main thread, but will create a new one (or fetch it from a cache) if called from within a different thread. That goes as follows:

+(NSManagedObjectContext *)managedObjectContext {
    MyAppDelegate *delegate = (MyAppDelegate *)[[UIApplication sharedApplication] delegate];
    NSManagedObjectContext *moc = delegate.managedObjectContext;

    NSThread *thread = [NSThread currentThread];

    if ([thread isMainThread]) {
        return moc;

    // a key to cache the context for the given thread
    NSString *threadKey = [NSString stringWithFormat:@"%p", thread];

    // delegate.managedObjectContexts is a mutable dictionary in the app delegate
    NSMutableDictionary *managedObjectContexts = delegate.managedObjectContexts;

    if ( [managedObjectContexts objectForKey:threadKey] == nil ) {
        // create a context for this thread
        NSManagedObjectContext *threadContext = [[[NSManagedObjectContext alloc] init] autorelease];
        [threadContext setPersistentStoreCoordinator:[moc persistentStoreCoordinator]];
        // cache the context for this thread
        [managedObjectContexts setObject:threadContext forKey:threadKey];

    return [managedObjectContexts objectForKey:threadKey];

Save operations are simple if called from the main thread. Save operations called from other threads require merging within the main thread. For that I have a generic commit function:

+(void)commit {
    // get the moc for this thread
    NSManagedObjectContext *moc = [self managedObjectContext];

    NSThread *thread = [NSThread currentThread];

    if ([thread isMainThread] == NO) {
        // only observe notifications other than the main thread
        [[NSNotificationCenter defaultCenter] addObserver:self

    NSError *error;
    if (![moc save:&error]) {
        // fail

    if ([thread isMainThread] == NO) {
        [[NSNotificationCenter defaultCenter] removeObserver:self 

In the contextDidSave: function we perform the merge, if called by the notification in commit.

+(void)contextDidSave:(NSNotification*)saveNotification {
    MyAppDelegate *delegate = (MyAppDelegate *)[[UIApplication sharedApplication] delegate];
    NSManagedObjectContext *moc = delegate.managedObjectContext;

    [moc performSelectorOnMainThread:@selector(mergeChangesFromContextDidSaveNotification:)

Finally, we clean-up the cache of NSManagedObjectContext with this:

+(void)initialize {
    [[NSNotificationCenter defaultCenter] addObserver:self 

+(void)threadExit {
    MyAppDelegate *delegate = (MyAppDelegate *)[[UIApplication sharedApplication] delegate];
    NSString *threadKey = [NSString stringWithFormat:@"%p", [NSThread currentThread]];  
    NSMutableDictionary *managedObjectContexts = delegate.managedObjectContexts;    

    [managedObjectContexts removeObjectForKey:threadKey];

This compiles and seems to work, but I know threading problems can be tricky due to race conditions. Does anybody see a problem with this approach?

Also, I'm using this from within the context of an asynchronous request (using ASIHTTPRequest), which fetches some data from a server and updates and inserts the store on the iPhone. It seems NSThreadWillExitNotification doesn't fire after the request completes, and the same thread is then used for subsequent requests. This means the same NSManagedObjectContext is used for separate requests on the same thread. Is this a problem?

Source: (StackOverflow)

ASIHTTPRequest / ASIFormDataRequest - referencing request object within blocks under ARC

Very similar to this question, I am trying to convert a project that uses ASIHTTPRequest & ASIFormDataRequest to ARC.

In my view controller classes, I often refer to and use properties of the request object in the completion blocks (looking at the response code, response data etc):

__block  ASIFormDataRequest *request = [ASIFormDataRequest requestWithURL:[NSURL URLWithString:SOME_URL]];    
[request setCompletionBlock:^{   

    if([request responseStatusCode] == 200) ....etc

When converting to ARC I get the warning:

Capturing 'request' strongly in this block is likely to lead to a retain cycle

What is the proper way to do this?

Another SO user notes in the previous thread that simply adding __weak may cause the request to be released before the completion of the block, which I believe to be true.

How can I properly reference these properties in completion/failure blocks under ARC?

Source: (StackOverflow)

UILabel text not being updated

I am unable to change the UILabel text. The code for the the UILabel inside viewDidLoad is :

startLabel=[[UILabel alloc] initWithFrame:CGRectMake(75, 395, 200, 30)];
startLabel.text=@"Recording Sound ...";
startLabel.backgroundColor=[UIColor clearColor];
startLabel.textColor=[UIColor whiteColor];
startLabel.font=[UIFont boldSystemFontOfSize:17];

[self.view addSubview:startLabel];

Later, if I want to change the label of the text with the following code, its not changing on the app :

startLabel.text=@"Searching Database ...";


[startLabel setText:@"Searching Database ..."];

The UILabel is not empty, I printed it out during debugging and it shows :

(gdb) po startLabel
<UILabel: 0x2c1a30; frame = (75 395; 200 30); text = 'Searching Database ...'; 
clipsToBounds = YES; userInteractionEnabled = NO; layer = <CALayer: 0x2ae8f0>>

So, the text of the label changes inside the UILabel, but its not updated on the screen.

Can anyone kindly let me know what I am missing here ? Thanks.

Edit 1: I tried performSelectorOnMainThread: - didnt work for me. Edit 2: I am using AVFoundation and ASIHTTP classes to record sound and upload the recorded file here. Nothing else. Didnt use any thread.

Source: (StackOverflow)

Why should I prefer ASIHTTPRequest over NSURLConnection for downloading files from the web?

I've seen a couple of times people using ASIHTTPRequest to download files. Now I wonder why? What are the core benefits over NSURLConnection?

Source: (StackOverflow)

Does AFNetworking have backgrounding support?

I'm in the process of investigating AFNetworking as a replacement for ASIHTTPRequest, and notice a complete lack of information on whether it supports background downloads/uploads.

With an ASIHTTPReqeust object, all you have to do is call [request setShouldContinueWhenAppEntersBackground:YES] and the request will continue in the background. Is there any support for this in AFNetworking?

Source: (StackOverflow)

Use a self-signed ssl certificate in an iphone app

I apologize in advance for the long-winded question. I'm having trouble with a self-signed SSL cert and I want to document everything I've tried so far.

I'm working on an app that communicates with a REST service. The test server uses a self-signed ssl certificate that I can install on my computer without issue. It's a .p12 file that requires a password to install. Without this certificate installed, all requests to the server return a 403.

The .p12 installs three items in the Keychain, a "Root certificate authority", a "test user" certificate that's issued by the "Root certificate authority", and a private key that's associated with the "test user" cert.

I've installed this certificate on my iPad by emailing myself the .p12 file. I tapped on the attachment, input the password, and I can now access the site in Safari. Unfortunately, because of application sandboxing, this isn't enough to get my app to communicate with the REST service.

I'm using ASIHTTPRequest for all of the communication with the REST service from my app. Each request is a subclass of ASIHTTPRequest. The first thing I found I had to do was call [self setValidatesSecureCertificate:NO]; so that it would even attempt the SSL connection to the server. If that's all I do, I get 403 error codes back from the service.

Now I can't seem to figure out how to get the request to use the certificate. I've tried exporting the three items as separate .cer file, including them in the project and adding them to the request using the code below:

NSData *data = [NSData dataWithContentsOfFile:[[NSBundle mainBundle] pathForResource:@"cert" ofType:@"cer"]];
SecCertificateRef cert = SecCertificateCreateWithData(NULL, (CFDataRef)data);
[self setClientCertificates:[NSArray arrayWithObjects:(id)cert, ..., nil]];

While the code executes without issue using this approach, I still get the 403 error.

I've even tried including the .p12 file in my application and importing it using the same code. This fails because SecCertificateCreateWithData returns nil.

I admit I don't really know what I'm doing here. This is all a little over my head and any help anyone could give me would be greatly appreciated.

Source: (StackOverflow)

ASIHTTPRequest: https with SSL

How to implement a https connection with SSL and ASIHTTPRequest? Are there some special steps to do? Can it be that this has nothing to do with ASIHTTPRequest? It has to do only with the server-side I think. Can someone post a link or describe the process of how a https connection can be established?

This is what I found out so far:

I read somewhere that you need a "real" SSL certificate and not a self signed one. There are also not all provider of SSL certificates supported I think (read this).

You also have to run through the U.S. Government requirement for a CCATS review and approval. (see here).

Source: (StackOverflow)

Best architecture for an iOS application that makes many network requests?

I'm in the process of rethinking my approach to the request architecture of a large app I'm developing. I'm currently using ASIHTTPRequest to actually make requests, but since I need many different types of requests as a result of many different actions taken in different view controllers, I'm trying to work out the best system of organizing these requests.

I'm currently building singleton "requesters" that are retained by the app delegate and sit around listening for NSNotifications that signal a request needs to be made; they make the request, listen for the response, and send out a new NSNotification with the response data. This solves most of my problems, but doesn't elegantly handle failed requests or simultaneous requests to the same singleton requester.

Anyone have any success devising a clear, OO architecture for making many different types of requests in an iOS app?

Source: (StackOverflow)

What major ASIHTTPRequest features is AFNetworking missing?

With work having recently stopped on ASIHTTPRequest, it seems like attention is shifting to AFNetworking.

However, I've not yet found a good comparison of the features of the two libraries, so I don't know what I might lose if/when I switch over.

Major differences I've spotted so far are:

  1. AFNetworking has a much smaller code size (which is good)
  2. AFNetworking is being rapidly improved (so it may not yet be mature, may not have a stable API yet?)
  3. Both seem to have caching, though I've seen hints that because AFNetworking uses NSURLConnection it won't cache objects over 50K
  4. ASIHTTPRequest has very good support for manual & automatic (PAC) http proxies; I can't find any information on what level of support AFNetworking has for proxies
  5. AFNetworking requires iOS 4+, whereas ASIHTTPRequest works right back to iOS 2 (not really an issue for me, but it is an issue for some people)
  6. AFNetworking doesn't (yet) have a built in persistent cache, but there's a persistent cache which has a pending pull request:

Has anyone seen any good comparisons of the two libraries or any documented experiences of switching from one to the other?

Source: (StackOverflow)

Fix warning "Capturing [an object] strongly in this block is likely to lead to a retain cycle" in ARC-enabled code

In ARC enabled code, how to fix a warning about a potential retain cycle, when using a block-based API?

The warning:
Capturing 'request' strongly in this block is likely to lead to a retain cycle

produced by this snippet of code:

ASIHTTPRequest *request = [[ASIHTTPRequest alloc] initWithURL:...

[request setCompletionBlock:^{
    NSDictionary *jsonDictionary = [[CJSONDeserializer deserializer] deserialize:request.rawResponseData error:nil];
    // ...

Warning is linked to the use of the object request inside the block.

Source: (StackOverflow)

How? UITableViewCell with UIImageView asynchronously loaded via ASINetworkQueue

I'm trying to load some images in table cells asynchronously using ASINetworkQueue. I just can't figure it out and can't seem to find a good SIMPLE example.

The best I can find is this, but its just totally overkill and a little too complicated for me:

Does anyone else have any tips/solutions/code for doing this with the ASIHTTPRequest library?

Source: (StackOverflow)

Best substitute, successor or alternative for ASIHTTP for a download queue

I've recently read the news on that ASIHTTP is being discontinued. I have much respect for the makers of the library. However, I am now looking for a substitute that also supports queued download (multithreaded) on iOS, that also supports a progress bar with appropriate information.

Is there any (hopefully lightweight) library, that is in an active development livecycle? ARC support would also be much appreciated.

Many thanks for your thoughts.

Source: (StackOverflow)