HTTP POST request in iOS [closed]

Answer 1

A couple of thoughts:

1. You NSLog your webData, which will always show <> (as your logging it immediately after instantiated it). I'm not sure why you're logging that.

   The question is whether you're seeing that <>, or the NSLog in connectionDidFinishLoading.

2. I ask that because you are not logging the error in connection:didFailWithError:, if it fails, you'll never know why. You really should log the error in connection:didFailWithError: so you know if it failed, and if so, why:

   NSLog(@"%s: %@", __FUNCTION__, error);
   

3. In your connection:didReceiveResponse:, you really should look at the HTTP status code:

   if ([response isKindOfClass:[NSHTTPURLResponse class]]) {
       NSInteger statusCode = [(NSHTTPURLResponse *)response statusCode];
   
       if (statusCode != 200)
           NSLog(@"%s: status code is %d; should be 200", __FUNCTION__, statusCode);
   }
   

   If it's not 200, you really want to know about that.

4. You report in one of your comments that you are seeing connectionDidFinishLoading: called, but never having didReceiveData called. That means (unsurprisingly) that there was no data received. So, you should:

   • Confirm that the connection:didReceiveResponse: reported a statusCode of 200; and

   • Confirm that the server code is working properly. I could imagine getting the behavior you describe if you had an error in your server PHP code (which is exacerbated by the fact that servers often have display_errors turned off in their php.ini file).

---

As an aside, if it's possible that the value associated with key1 might contain any reserved characters (as defined in section 2 of RFC 3986), you should percent-escape the string using CFURLCreateStringByAddingPercentEscapes. Thus:

NSString *post = [NSString stringWithFormat:@"key1=%@", [self percentEscapeString:vali]];

Where, per the W3C specs for application/x-www-form-urlencoded, you not only percent escape, but also replace spaces with + characters, thus:

- (NSString *)percentEscapeString:(NSString *)string
{ 
    NSString *result = CFBridgingRelease(CFURLCreateStringByAddingPercentEscapes(kCFAllocatorDefault,
                                                                                 (CFStringRef)string,
                                                                                 (CFStringRef)@" ",
                                                                                 (CFStringRef)@":/?@!$&'()*+,;=",
                                                                                 kCFStringEncodingUTF8));
    return [result stringByReplacingOccurrencesOfString:@" " withString:@"+"];
}

Answer 2

Use:

+ (void)sendAsynchronousRequest:(NSURLRequest *)request queue:(NSOperationQueue *)queue completionHandler:(void (^)(NSURLResponse*, NSData*, NSError*))handler

Unless you have a compelling reason not to.

Example (probably non-working):

Note creating postData.

-(void)sendRequest {
    NSString *vali = @"$uppl!3r$";
    NSString *post = [NSString stringWithFormat:@"key1=%@",vali];
    NSData *postData = [post dataUsingEncoding:NSUTF8StringEncoding];
    NSString *postLength = [NSString stringWithFormat:@"%lu", [postData length]];
    NSLog(@"%@", postLength);

    NSMutableURLRequest *request = [[NSMutableURLRequest alloc] init];
    [request setURL:[NSURL URLWithString:@"http://www.ddemo3.enerjinet.com/webservices/ios/suppliers.php"]];
    [request setHTTPMethod:@"POST"];
    [request setValue:postLength forHTTPHeaderField:@"Content-Length"];
    [request setValue:@"application/x-www-form-urlencoded" forHTTPHeaderField:@"Content-Type"];
    [request setHTTPBody:postData];

    [NSURLConnection sendAsynchronousRequest:request
                                       queue:[NSOperationQueue mainQueue]
                           completionHandler:^(NSURLResponse *response, NSData *data, NSError *error) {

                               NSLog(@"data: %@", data);

                           }];
}

Oh, make life easier, use ARC.