Display Direction using google api in ios get - ios

Question

In Below code run so i get a response from url but when i try to get encodedPoints it give me a null value. also i update RegexKitLite but prob. not solve. Any suggestion are welcome Thank you advance.
NSString* saddr = [NSString stringWithFormat:#"%f,%f", f.latitude, f.longitude];
NSString* daddr = [NSString stringWithFormat:#"%f,%f", t.latitude, t.longitude];
NSString* apiUrlStr = [NSString stringWithFormat:#"http://maps.googleapis.com/maps/api/directions/json?origin=%#&destination=%#&sensor=false", saddr, daddr];
// http://maps.googleapis.com/maps/api/directions/json?origin=41.029598,28.972985&destination=41.033586,28.984546&sensor=false%EF%BB%BF%EF%BB%BF
NSURL *apiUrl = [NSURL URLWithString:[apiUrlStr stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]];
NSLog(#"api url: %#", apiUrl);
NSString *apiResponse = [NSString stringWithContentsOfURL:apiUrl encoding:nil error:nil];
NSString* encodedPoints = [apiResponse stringByMatching:#"points:\\\"([^\\\"]*)\\\"" capture:1L];
NSLog(#"encodedPoints: %#", encodedPoints);
if (encodedPoints) {
return [self decodePolyLine:[encodedPoints mutableCopy]];
}
else {
return NO;
}

Answer 1

I think its not a good way to do API request synchronously, especially when user' phone has poor internet connection, it will slow down the responsiveness of your application. So you should do an asynchronous API request with NSURLSession.
Also, the Directions API might return more than one routes for your request. So its better to use a NSArray to store your polyline points.
Sample code:
- (void)getPolyline {
NSURL *url = [[NSURL alloc] initWithString:#"https://maps.googleapis.com/maps/api/directions/json?origin=Chicago,IL&destination=Los+Angeles,CA&key=YOUR_API_KEY"];
NSURLRequest *request = [[NSURLRequest alloc] initWithURL: url];
NSURLSession *session = [NSURLSession sharedSession];
[[session dataTaskWithRequest:request completionHandler:
^(NSData * _Nullable data, NSURLResponse * _Nullable response, NSError * _Nullable error) {
if (!error) {
NSError *jsonError;
NSDictionary *dict = (NSDictionary*)[NSJSONSerialization JSONObjectWithData:data options:nil error:&jsonError];
if (!jsonError) {
NSArray *routesArray = (NSArray*)dict[#"routes"];
NSMutableArray *points = [NSMutableArray array];
for (NSDictionary *route in routesArray) {
NSDictionary *overviewPolyline = route[#"overview_polyline"];
[points addObject:overviewPolyline[#"points"]];
}
NSLog(#"%#", points);
}
} else {
//print error message
NSLog(#"%#", [error localizedDescription]);
}
}] resume];
}