How do I receive responce after I POST data to an url? - ios

Question

I have this code;
NSString *post = [NSString stringWithFormat:#"latitude=%lf&longitude=%lf&provider=network&accuracy=%lf&hiz=%lf&retrieveTime=%#",
locationManager.location.coordinate.latitude,
locationManager.location.coordinate.longitude,
locationManager.location.horizontalAccuracy,
locationManager.location.speed,
dateString];
NSData *postData = [post dataUsingEncoding:NSASCIIStringEncoding allowLossyConversion:YES];
NSString *postLength = [NSString stringWithFormat:#"%lu", [postData length]];
NSMutableURLRequest *request = [[NSMutableURLRequest alloc] init];
NSString *sUrl = [[NSUserDefaults standardUserDefaults] stringForKey:#"serviceUrl"];
NSString *swoclString = [NSString stringWithFormat:#"%#/saveLocation.php", sUrl];
[request setURL:[NSURL URLWithString:swoclString]];
[request setHTTPMethod:#"POST"];
[request setValue:postLength forHTTPHeaderField:#"Content-Type"];
[request setValue:#"application/x-www-form-urlencoded" forHTTPHeaderField:#"Content-Type"];
[request setHTTPBody:postData];
NSURLConnection *conn = [[NSURLConnection alloc] initWithRequest:request delegate:self];
if(conn) {
NSLog(#"Location Save Successfully");
} else {
NSLog(#"Location Save Error");
}
I can receive the data in the server side. And on the iOS side I can see the log "Location Save Successfully".
How can I receive the response from the server without implementing other methods?

Answer 1

Use NSURLSession instead of NSURLConnection to post your data to the Server. Below is an example how you can post JSON.
NSURLSessionConfiguration *config = [NSURLSessionConfiguration defaultSessionConfiguration];
NSURLSession *session = [NSURLSession sessionWithConfiguration:config delegate:nil delegateQueue:nil];
NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:[NSURL URLWithString:#"<YOUR-URL-STRING>"] cachePolicy:NSURLRequestReloadIgnoringCacheData timeoutInterval:120.0];
[request setHTTPMethod:#"POST"];
[request addValue:#"application/json" forHTTPHeaderField:#"Content-Type"];
[request addValue:#"application/json" forHTTPHeaderField:#"Accept"];
NSError *error;
NSData *postData = [NSJSONSerialization dataWithJSONObject:<YOUR_JSON_DATA> options:NSJSONWritingPrettyPrinted error:&error];
NSString *tmp = [[NSString alloc]initWithData:postData encoding:NSUTF8StringEncoding];
[request setHTTPBody:postData];
NSURLSessionDataTask *dataTask = [session dataTaskWithRequest:request completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) {
NSHTTPURLResponse *resp = (NSHTTPURLResponse *) response;
NSLog(#"%li",(long)resp.statusCode);
if(resp.statusCode==200){
NSMutableArray *result = [NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingAllowFragments error:&jsonError];
}];`
The block is used to return the response by the server. For example the HTTP-Status Code and the response data. If you use json you can convert the Data with the NSJSONSerialization class.

Answer 2

If you are using latest ios coding standards you must have to use URLSession object to send any request to the API calls because DEPRECATED: The NSURLConnection class should no longer be used. NSURLSession is the replacement for NSURLConnection. But still, if you want to continue with an old procedure, there are three ways to send API request.
P1:
-(void)procedure1{
NSURLRequest *requestObject = nil; /** replace with your request object **/
NSURLResponse *serverResponse = nil;
NSError *connectError = nil;
/* thread bloker request */
NSData *responseData = [NSURLConnection sendSynchronousRequest:requestObject returningResponse:&serverResponse error:&connectError];
if (connectError == nil) {
//parse server response data (i.e, json or xml)
}else{
/* handle connection error */
}
}
P2:
-(void)procedure2{
NSURLRequest *requestObject = nil; /** replace with your request object **/
/* thread free request */
[NSURLConnection sendAsynchronousRequest:requestObject queue:[NSOperationQueue mainQueue] completionHandler:^(NSURLResponse * _Nullable response, NSData * _Nullable data, NSError * _Nullable connectionError) {
if (connectionError == nil) {
//parse server response data (i.e, json or xml)
}else{
/* handle connection error */
}
}];
}
P3:
the last one is a bit different than the other two,
#interface TestViewController ()<NSURLConnectionDelegate>
#property (nonatomic, retain) NSMutableData* responseData;
#end
-(void)procedure3{
NSURLRequest *requestObject = nil; /** replace with your request object **/
NSURLConnection *connectionObject = [NSURLConnection connectionWithRequest:requestObject delegate:self];
[connectionObject start];
}
here in this procedure you are required to invoke NSURLConnectionDelegate methods
- (void) connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response {
[self.responseData setLength:0];
}
- (void) connection:(NSURLConnection *)connection didReceiveData:(NSData *)data {
[self.responseData appendData:data];
}
- (void) connectionDidFinishLoading:(NSURLConnection *)connection {
NSString* responseString = [[NSString alloc] initWithData:self.responseData encoding:NSUTF8StringEncoding];
connection = nil;
}