Question

I need to load data from my API without waiting 20s each time I launch my application.

So I use:

NSURL *myUrlCourses = [[NSURL alloc] initWithString:url];
NSMutableURLRequest *request = [NSURLRequest requestWithURL: myUrlCourses];
NSURLConnection *connexion = [[NSURLConnection alloc] initWithRequest:request delegate:self];

for my 10 first request in while loop which permit to get data in background.
But, when I get data from this request with:

- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data{}
- (void)connectionDidFinishLoading:(NSURLConnection *)connection{}

The result don’t match.
So, I think I have to use thread or something like that to get the right data for each request but I don’t really know how!?

Could you help me to solve this problem?

Thanks

Answer 1

I use a CFMutableDictionaryRef to save another mutable dictionary for each connection. This inner dictionary can hold as much data as you want.

like this:

@interface Foo {
    CFMutableDictionaryRef connections;
}


@implementation Foo

- (id)init {
    self = [super init];
    if (self) {
        connections = CFDictionaryCreateMutable(kCFAllocatorDefault, 0, &kCFTypeDictionaryKeyCallBacks, &kCFTypeDictionaryValueCallBacks);
    }
    return self;
}

- (BOOL)addURLRequest:(NSURLRequest *)request successSelector:(SEL)successSelector errorSelector:(SEL)errorSelector {
    NSMutableDictionary *connectionInfo = [NSMutableDictionary dictionaryWithObjectsAndKeys:
                                           [NSMutableData data], @"receivedData",
                                           [NSValue valueWithPointer:successSelector], @"successSelector",
                                           [NSValue valueWithPointer:errorSelector], @"errorSelector",
                                           request, @"request",
                                           nil];
    NSURLConnection *connection = [[[NSURLConnection alloc] initWithRequest:request delegate:self startImmediately:NO] autorelease];
    CFDictionaryAddValue(connections, connection, connectionInfo);
    [connection start];
    return YES;
}

- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data {
    NSMutableDictionary *connectionInfo = (NSMutableDictionary *)CFDictionaryGetValue(connections, connection);
    [[connectionInfo objectForKey:@"receivedData"] appendData:data];
}

- (void)connectionDidFinishLoading:(NSURLConnection *)connection {
    NSMutableDictionary *connectionInfo = (NSMutableDictionary *)CFDictionaryGetValue(connections, connection);
    NSData *data = [connectionInfo objectForKey:@"receivedData"];
    LogInfo(@"Finished Connection %@", connection);
    SEL selector = [[connectionInfo objectForKey:@"successSelector"] pointerValue];
    if ([self respondsToSelector:selector]) {
        [self performSelector:selector withObject:data];
    }
    CFDictionaryRemoveValue(connections, connection);
}