Run request operations in loop inside operation - ios

Question

How can I run multiple requests inside the success block of 1 request and wait for it to finish?
[manager GET:url parameters:params success:^(AFHTTPRequestOperation *operation, id responseObject) {
NSLog(#"%# Response: \n%#", url, responseObject);
resultsArray = [[NSMutableArray alloc] init];
for (NSDictionary *json in [responseObject objectForKey:#"items"]) {
[self getDetails:json];
}
} failure:^(AFHTTPRequestOperation *operation, NSError *error) {
[SVProgressHUD dismiss];
}];
Where in getDetails:(id)json is the method to load the group of requests whose parameters are based on the result of the main request.
For example:
I would like to request from the API a list of students, then on the success block. For each student, I would like to get the related data from another table (another request) and put them on my NSObject.
EDIT Here is my getDetails method
- (AFHTTPRequestOperation *)getDetails:(NSDictionary *)json
{
NSLog(#"Start Op %#",[json objectForKey:#"related_salon"]);
NSString *url = [NSString stringWithFormat:#"%#read/salons/%#",SERVER_API_URL,[json objectForKey:#"related_salon"]];
NSURLRequest *req = [NSURLRequest requestWithURL:[NSURL URLWithString:url]];
AFHTTPRequestOperation *op = [[AFHTTPRequestOperation alloc] initWithRequest:req];
//op.responseSerializer = [AFJSONResponseSerializer serializer];
[op setCompletionBlockWithSuccess:^(AFHTTPRequestOperation *operation, id responseObject) {
NSLog(#"Success %#",[json objectForKey:#"name"]);
} failure:^(AFHTTPRequestOperation *operation, NSError *error) {
NSLog(#"Failed Op %#",error.localizedDescription);
}];
//AFHTTPRequestOperation *op = [[AFHTTPRequestOperation alloc] initWithRequest:req];
//op.responseSerializer = [AFJSONResponseSerializer serializer];
[op start];
return op;
}

Answer 1

The AFNetworking GET method returns a ATHTTPRequestOperation (an NSOperation subclass). You could have your getDetails method return that object. You can then create a new operation dependent upon those operations, which you'd run at the end:
NSOperation *completionOperation = [NSBlockOperation blockOperationWithBlock:^{
// add here whatever you want to perform when all the getDetails calls are done,
// e.g. maybe you want to dismiss your HUD when all the requests are done.
[SVProgressHUD dismiss];
}];
[manager GET:url parameters:params success:^(AFHTTPRequestOperation *operation, id responseObject) {
NSLog(#"%# Response: \n%#", url, responseObject);
resultsArray = [[NSMutableArray alloc] init];
for (NSDictionary *json in [responseObject objectForKey:#"items"]) {
NSOperation *operation = [self getDetails:json];
[completionOperation addDependency:operation];
}
[[NSOperationQueue mainQueue] addOperation:completionOperation];
} failure:^(AFHTTPRequestOperation *operation, NSError *error) {
[SVProgressHUD dismiss];
}];
Again, this is presuming that getDetails is doing its own GET call, and that you change getDetails to (a) capture the NSOperation returned by GET and (b) return it.