How to send JSON request to service with parameters in Objective-C - objective-c

Question

I'm creating a iPhone app, and im trying to figure out how to create a JSON request to the webservice that contains parameters. In Java this would look like this
HashMap<String, String> headers = new HashMap<String, String>();
JSONObject json = new JSONObject();
json.put("nid", null);
json.put("vocab", null);
json.put("inturl", testoverview);
json.put("mail", username); // something#gmail.com
json.put("md5pw", password); // donkeykong
headers.put("X-FBR-App", json.toString());
The header has to contain a JSON object and "X-FBR-App" before the service recognizes the request. How would this be implemented in Objective-C ?

Answer 1

USE Post method.try this
NSString *method = #"addProduct";
NSString *jsonstring=#"http://yourdomain.com/product_review_api/product-review.php?";
NSString *urlString = [NSString stringWithFormat:#"%#",jsonstring];
NSMutableURLRequest *request = [[[NSMutableURLRequest alloc] init] autorelease];
[request setURL:[NSURL URLWithString:urlString]];
[request setHTTPMethod:#"POST"];
NSMutableData *body = [NSMutableData data];
// image file
NSData *imageData = UIImageJPEGRepresentation( labelimage, 0.8);
NSString *boundary = [NSString stringWithString:#"---------------------------14737809831466499882746641449"];
NSString *contentType = [NSString stringWithFormat:#"multipart/form-data; boundary=%#",boundary];
[request addValue:contentType forHTTPHeaderField: #"Content-Type"];
// parameter method
[body appendData:[[NSString stringWithFormat:#"--%#\r\n", boundary] dataUsingEncoding:NSUTF8StringEncoding]];
[body appendData:[[NSString stringWithFormat:#"Content-Disposition: form-data; name=\"method\"\r\n\r\n"] dataUsingEncoding:NSUTF8StringEncoding]];
[body appendData:[method dataUsingEncoding:NSUTF8StringEncoding]];
[body appendData:[[NSString stringWithString:#"\r\n"] dataUsingEncoding:NSUTF8StringEncoding]];
// parameter categoryid
[body appendData:[[NSString stringWithFormat:#"--%#\r\n", boundary] dataUsingEncoding:NSUTF8StringEncoding]];
[body appendData:[[NSString stringWithFormat:#"Content-Disposition: form-data; name=\"category_id\"\r\n\r\n"] dataUsingEncoding:NSUTF8StringEncoding]];
[body appendData:[selectedID dataUsingEncoding:NSUTF8StringEncoding]];
[body appendData:[[NSString stringWithString:#"\r\n"] dataUsingEncoding:NSUTF8StringEncoding]];
[request setHTTPBody:body];
// now lets make the connection to the web
NSData *returnData = [NSURLConnection sendSynchronousRequest:request returningResponse:nil error:nil];
NSString *returnString = [[NSString alloc] initWithData:returnData encoding:NSUTF8StringEncoding];
NSLog(#"%#",returnString);
NSDictionary *profile = (NSDictionary*)[returnString JSONValue];
NSLog(#"profile=%#", profile);
you can append all the parameters like this.

Answer 2

JSON isn't baked into iOS, but if you look at www.JSON.org there are a number of Objective-C frameworks that provide the required functionality. I have no experience with any of them so I can't make recommendations, but it is a good start to finding a solution.
Also look at this SO question post-data-through-json-webservices-in-iphone