How do make Json request to server? - objective-c

Question

I'm doing an application that should work with the server.
Need to be authorized on the server through the program using the username and password.
I need to make a request to the server with the line:
{"login": "mad_fashist", "password": "eqeeuq313371", "method": "authentificator"}
The string must be in Json.
In response, I should get a line if authentication fails:
{"validated": "false", "kuid": "", "sid": "", "uid": ""}
And if authentication is passed:
{"validated":"true","kuid":"6","sid":"834fe9b4626502bf9ff23485a408ac40","uid":"69"}
The question is how to send and receive all of the above?

Answer 1

Use SBJson framework. and do smth like:
-(void)requestProjects
{
//I prepare the string
NSString *preparedString=[NSString stringWithFormat:#"%# %#", self.lastDate, self.currentCategory];
NSDictionary *jsonDict = [NSDictionary dictionaryWithObject:preparedString forKey:#"request"];
//Prepare convert to json string
NSString *jsonRequest = [jsonDict JSONRepresentation];
NSLog(#"jsonRequest is %#", jsonRequest);
//Set the URL YOU WILL PROVIDE
NSURL *url = [NSURL URLWithString:#"http:xxxxxxxxxxxxxxxxxxx"];
//PREPARE the request
NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url
cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:60.0];
//Prepare data which will contain the json request string.
NSData *requestData = [NSData dataWithBytes:[jsonRequest UTF8String] length:[jsonRequest length]];
//Set the propreties of the request
[request setHTTPMethod:#"POST"];
[request setValue:#"application/json" forHTTPHeaderField:#"Accept"];
[request setValue:#"application/json" forHTTPHeaderField:#"Content-Type"];
[request setValue:[NSString stringWithFormat:#"%d", [requestData length]] forHTTPHeaderField:#"Content-Length"];
[request setValue:jsonRequest forHTTPHeaderField:#"Query-string"];
//set the data prepared
[request setHTTPBody: requestData];
//Initialize the connection with request
NSURLConnection *connection = [[NSURLConnection alloc]initWithRequest:request delegate:self];
//Start the connection
[delegate showIndicator];
[connection start];
}
//delegate methods:
//METHODS TO HANßDLE RESPONSE
#pragma mark NSURLConnection delegate methods
//WHen receiving the response
- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response {
NSLog(#" Did receive respone");
[responseData setLength:0];
}
- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data {
//While receiving the response data
[responseData appendData:data];
}
- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error {
//When failed just log
[delegate hideIndicator];
NSLog(#"Connection failed!");
NSLog(#"Error %#", error);
}
- (void)connectionDidFinishLoading:(NSURLConnection *)connection {
//When the response data is downloaded
// NSLog(#" Data obtained %#", responseData);
NSString *responseString = [[NSString alloc] initWithData:responseData encoding:NSUTF8StringEncoding];
// NSLog(#" Response String %#", responseString);
//converted response json string to a simple NSdictionary
//If the response string is really JSONABLE I will have the data u sent me displayed succefully
NSMutableArray *results = [responseString JSONValue];
NSLog(#"Response: %#", results);
/// la la al alal alaa
}
It's your back end who should define how the response in Json will look like

Answer 2

Refer NSJsonSerialization class. Which is newly included in ios5.0. which is the most flexible one for your need. you can access it in apple developer site.
link to NSJSONSerialization