Run a method when AFMultipartFormData is finished uploading - ios

Question

I'm sending multiple images to server using AFMultipartFormData using a for loop to fetch one image at a time:
NSString *string = [NSString stringWithFormat:#"%#/API/Upload",BaseURLString];
AFHTTPSessionManager *manager = [AFHTTPSessionManager manager];
[manager setRequestSerializer:[AFHTTPRequestSerializer serializer]];
[manager setResponseSerializer:[AFHTTPResponseSerializer serializer]];
NSError *error;
NSString *mystring = #"noName";
//FOR Loop Start
for(NSData *eachImage in dataStringArray) {
NSURLRequest *request = [manager.requestSerializer multipartFormRequestWithMethod:#"POST" URLString:string parameters:nil constructingBodyWithBlock:^(id<AFMultipartFormData> formData) {
[formData appendPartWithFormData:eachImage name:#"myImage"];
[formData appendPartWithFormData:[mystring dataUsingEncoding:NSUTF8StringEncoding]
name:#"FileName"];
} error:&error];
NSURLSessionDataTask *task = [manager dataTaskWithRequest:request uploadProgress:nil downloadProgress:nil completionHandler:^(NSURLResponse * _Nonnull response, id _Nullable responseObject, NSError * _Nullable error) {
if (error) {
NSLog(#"%#", error.localizedDescription);
return;
}
[uploadedImageIDs addObject:[[NSString alloc] initWithData:responseObject encoding:NSUTF8StringEncoding]];
}];
[task resume];
}//for end
[self makeJSON:uploadedImageIDs];
But somehow it calls makeJSON method before. As there are multiple images so I need it to call after the uploading is finished for all images.

Answer 1

Network processing will run by asynchronous so you need to count in network completionHanlder for knowing when all task finished. Like this
NSString *string = [NSString stringWithFormat:#"%#/API/Upload",BaseURLString];
AFHTTPSessionManager *manager = [AFHTTPSessionManager manager];
[manager setRequestSerializer:[AFHTTPRequestSerializer serializer]];
[manager setResponseSerializer:[AFHTTPResponseSerializer serializer]];
NSError *error;
NSString *mystring = #"noName";
NSInteger count = 0;
//FOR Loop Start
for(NSData *eachImage in dataStringArray) {
NSURLRequest *request = [manager.requestSerializer multipartFormRequestWithMethod:#"POST" URLString:string parameters:nil constructingBodyWithBlock:^(id<AFMultipartFormData> formData) {
[formData appendPartWithFormData:eachImage name:#"myImage"];
[formData appendPartWithFormData:[mystring dataUsingEncoding:NSUTF8StringEncoding]
name:#"FileName"];
} error:&error];
NSURLSessionDataTask *task = [manager dataTaskWithRequest:request uploadProgress:nil downloadProgress:nil completionHandler:^(NSURLResponse * _Nonnull response, id _Nullable responseObject, NSError * _Nullable error) {
count++;
if (error) {
NSLog(#"%#", error.localizedDescription);
} else {
[uploadedImageIDs addObject:[[NSString alloc] initWithData:responseObject encoding:NSUTF8StringEncoding]];
}
if (count == dataStringArray.count) {
[self makeJSON:uploadedImageIDs];
}
}];
[task resume];
}//for end