NSURLConnection delegate method

Question

I am having a hard time to find any examples for NSURLConnection delegate method implementations.

I want to send data with a HTTP post with a button click. Not sure how to make a "submitting" screen and "submitted". (I know how to use spinner and will use them)

I am using this code under a botton click action, but unable to use any delegate stuff. Not sure how to implement them with my current set up.

NSMutableURLRequest *request = 
    [[NSMutableURLRequest alloc] initWithURL:
     [NSURL URLWithString:@"http://myURL.com"]];

    [request setHTTPMethod:@"POST"];

    NSString *postString = [wait stringByAppendingString:co];

    [request setValue:[NSString 
                       stringWithFormat:@"%d", [postString length]] 
   forHTTPHeaderField:@"Content-length"];



    [request setHTTPBody:[postString 
                          dataUsingEncoding:NSUTF8StringEncoding]];

    //[[NSURLConnection alloc] initWithRequest:request delegate:self];
    [NSURLConnection sendSynchronousRequest:request returningResponse:nil error:nil];


    [SVProgressHUD dismissWithSuccess:@"Submission Successful"];

Answer 1

- (void)connection:(NSURLConnection*)connection didReceiveResponse:(NSURLResponse *)response
{
    NSLog(@"Did Receive Response %@", response);
    responseData = [[NSMutableData alloc]init];
}
- (void)connection:(NSURLConnection*)connection didReceiveData:(NSData*)data
{
    //NSLog(@"Did Receive Data %@", data);
    [responseData appendData:data];
}
- (void)connection:(NSURLConnection*)connection didFailWithError:(NSError*)error
{
    NSLog(@"Did Fail");
}
- (void)connectionDidFinishLoading:(NSURLConnection *)connection
{
    NSLog(@"Did Finish");
    // Do something with responseData
}

Answer 2

You need to use the new NSURLConnectionDataDelegate protocol.

I found some exemples here:

http://blog.kemalkocabiyik.com/index.php/2012/02/fetching-data-with-getpost-methods-by-using-nsurlconnection/

And if you can read portuguese: http://www.quaddro.com.br/blog/desenvolvimento-ios/baixando-conteudo-com-nsurlconnection-e-nsurlconnectiondatadelegate-no-ios

Answer 3

//Connection request
 -(void)requestURL:(NSString *)strURL
    {
        // Create the request.
        NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:strURL]];

        // Create url connection and fire request
        NSURLConnection *conn = [[NSURLConnection alloc] initWithRequest:request delegate:self];

    }


    //Delegate methods
    - (void)connection:(NSURLConnection*)connection didReceiveResponse:(NSURLResponse *)response
    {
        NSLog(@"Did Receive Response %@", response);
        responseData = [[NSMutableData alloc]init];
    }
    - (void)connection:(NSURLConnection*)connection didReceiveData:(NSData*)data
    {
        //NSLog(@"Did Receive Data %@", data);
        [responseData appendData:data];
    }
    - (void)connection:(NSURLConnection*)connection didFailWithError:(NSError*)error
    {
        NSLog(@"Did Fail");
    }
    - (void)connectionDidFinishLoading:(NSURLConnection *)connection
    {
        NSLog(@"Did Finish");
        // Do something with responseData

        NSString *strData=[[NSString alloc] initWithData:responseData encoding:NSASCIIStringEncoding];

        NSLog(@"Responce:%@",strData);
    }

http://codewithchris.com/tutorial-how-to-use-ios-nsurlconnection-by-example/

Answer 4

in this code you will use GCD ,Activity Indicator ,UIButton Action on login button First you will call StartActivityindicator on another thread and it keeps in moving until you remove or stop the Activityindicator. then you will call the web service for login in GCD queue . at the time you receive response from server call main queue to update the UI.

// After the interface declration 
@interface LoginViewController ()
{

NSData *responseData;
dispatch_queue_t myqueue;

}    
//Button Action 
- (IBAction)Login_Button_Action:(id)sender

{

 [NSThread detachNewThreadSelector: @selector(StartActivityindicator) toTarget:self withObject:nil];
myqueue =dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH, 0);
dispatch_group_t group=dispatch_group_create();
dispatch_group_async(group, myqueue, ^{ [self loginWebService];});
}
-(void)loginWebService
{
//Combine Both url and parameters
    NSString *UrlWithParameters = [NSString stringWithFormat:@"http://www.xxxxx.com?count=%@&user=%@&email=%@&password=%@",@"4",@"Username",s@"UserEmail",@"PAssword String"];
//Pass UrlWithParameters to NSURL
NSURL *ServiceURL =[NSURL URLWithString:UrlWithParameters];

NSMutableURLRequest *serviceRequest =[NSMutableURLRequest requestWithURL:ServiceURL];
[serviceRequest setHTTPMethod:@"POST"];

[serviceRequest setValue:@"application/json" forHTTPHeaderField:@"accept"];
[serviceRequest setValue:@"application/json" forHTTPHeaderField:@"content-type"];

//GEt Response Here
NSError *err;
NSURLResponse *response;
responseData = [NSURLConnection sendSynchronousRequest:serviceRequest returningResponse:&response error:&err];

NSHTTPURLResponse* httpResponse = (NSHTTPURLResponse*)response;
NSInteger code = [httpResponse statusCode];
// check status code for response from server and do RND for code if you recive anything than 200 
NSLog(@"~~~~~ Status code: %ld",(long)code);
if (code ==200)
{
 // your response is here if you call right  
    NSArray *jsonArray = [NSJSONSerialization JSONObjectWithData:responseData options: NSJSONReadingMutableContainers error: &err];  

 dispatch_async(dispatch_get_main_queue(),^{
       // place the code here to update UI with your received response 
        [NSThread detachNewThreadSelector: @selector(StopActivityindicator) toTarget:self withObject:nil];
        });
}
}
//Activity indicator Method to display 
- (void) StartActivityindicator
{
mySpinner.hidden = NO;
[mySpinner startAnimating];
}
- (void) StopActivityindicator
{
mySpinner.hidden = YES;
[mySpinner stopAnimating];
}