Facing an issue with NSURLSessionDataTask with SynchronousRequest in objective-c - objective-c

Question

Here is my working code with NSURLConnection sendSynchronousRequest :
+ (Inc*)getData:(NSString*)inUUID {
NSString* urlString = [NSString stringWithFormat:#"/inc/%#", incUUID];
NSURLRequest* request = [[HttpRequest requestWithRelativePath:urlString] toNSMutableURLRequest];
NSDictionary* json = [self getJSONForRequest:request];
return [Inc incFromDictionary:json];
}
+ (NSDictionary*)getJSONForRequest:(NSURLRequest*)request {
NSData* responseData = [NSURLConnection sendSynchronousRequest:request returningResponse:nil error:nil];
return [NSJSONSerialization JSONObjectWithData:responseData options:NSJSONReadingAllowFragments error:nil];
}
But, sendSynchronousRequest:request is deprecated.
So that, I used NSURLSessionDataTaskinstead of sendSynchronousRequest. Here, is the code which I implemented:
+ (Inc*)getData1:(NSString*)inUUID {
NSString* urlString = [NSString stringWithFormat:#"/in/%#", inUUID];
NSURLRequest* request = [[HttpRequest requestWithRelativePath:urlString] toNSMutableURLRequest];
//NSDictionary* json = [self getJSONForRequest1:request];
__block NSDictionary* json;
dispatch_async(dispatch_get_main_queue(), ^{
[self getJsonResponse1:request success:^(NSDictionary *responseDict) {
json = [responseDict valueForKeyPath:#"detail"];;
//return [Inc incFromDictionary:json];
} failure:^(NSError *error) {
// error handling here ...
}];
});
return [Inc incFromDictionary:json];
}
+ (void)getJsonResponse1:(NSURLRequest *)urlStr success:(void (^)(NSDictionary *responseDict))success failure:(void(^)(NSError* error))failure
{
NSURLSessionDataTask *dataTask1 = [[NSURLSession sharedSession] dataTaskWithRequest:urlStr completionHandler:^(NSData *data, NSURLResponse *response,
NSError *error) {
NSLog(#"%#",data);
if (error)
failure(error);
else {
NSDictionary *json = [NSJSONSerialization JSONObjectWithData:data options:0 error:nil];
NSLog(#"%#",json);
success(json);
}
}];
[dataTask1 resume]; // Executed First
}
The problem is return statement call in getData1 before finish the api call.
Thanks in advance.

Answer 1

As mentioned in the comments you need a completion handler.
Something like this (untested):
+ (void)getData1:(NSString*)inUUID success:(void (^)(NSDictionary *responseDict))success failure:(void(^)(NSError* error))failure {
NSString* urlString = [NSString stringWithFormat:#"/in/%#", inUUID];
NSURLRequest* request = [[HttpRequest requestWithRelativePath:urlString] toNSMutableURLRequest];
[self getJsonResponse1:request success:^(NSDictionary *responseDict) {
NSDictionary* json = [responseDict valueForKeyPath:#"detail"];
success(json);
} failure:^(NSError *error) {
failure(error);
}];
}
+ (void)getJsonResponse1:(NSURLRequest *)urlStr success:(void (^)(NSDictionary *responseDict))success failure:(void(^)(NSError* error))failure
{
NSURLSessionDataTask *dataTask1 = [[NSURLSession sharedSession] dataTaskWithRequest:urlStr completionHandler:^(NSData *data, NSURLResponse *response,
NSError *error) {
NSLog(#"%#",data);
if (error)
failure(error);
else {
NSDictionary *json = [NSJSONSerialization JSONObjectWithData:data options:0 error:nil];
NSLog(#"%#",json);
success(json);
}
}];
[dataTask1 resume]; // Executed First
}
And to call
[MyClass getData1:#"asdf" success:^(NSDictionary *responseDict) {
dispatch_async(dispatch_get_main_queue(), ^{
NSDictionary *json = [responseDict valueForKeyPath:#"detail"];
Inc *inc = [Inc incFromDictionary:json];
// do something witrh `inc`
});
} failure:^(NSError *error) {
// error handling here ...
}];
Consider to use instances and instance methods of your class(es) rather than only class methods.