iOS - Extra param in POST request - ios

Question

I am new on iOS development. I try to send POST JSON to my RoR server.
It is my code:
params - some NSDictionary -> { uid = 123 }
NSData *postData = [NSJSONSerialization dataWithJSONObject:params
options:NSJSONWritingPrettyPrinted error:&jsonSerializationError];
NSString *urlString = [[NSString alloc] initWithFormat:#"%#%#", API_URL, url];
NSURL *nsUrl = [NSURL URLWithString:urlString];
NSMutableURLRequest *request = [[NSMutableURLRequest alloc] initWithURL:nsUrl];
[request setHTTPMethod:#"POST"];
[request setValue:[NSString stringWithFormat:#"%lu",
(unsigned long)postData.length] forHTTPHeaderField:#"Content-Length"];
[request setValue:#"application/json" forHTTPHeaderField:#"Content-Type"];
[request setHTTPBody:postData];
At the end in the server I see:
{"uid"=>"123",
"action"=>"mAction",
"controller"=>"mController",
"token"=>{"uid"=>"123"}}
Why I see 'extra token' and how I can remove it ?

Answer 1

there is no reason I can see for the extra "token" to be there, so I would suggest that either the token was in the param all along, or that the receiving script (PHP?) on the server is adding the data someway.
I would suggest you to print the content of parameter with
NSLog(#"param: %#", param);
just to be sure, and also convert the postData to a NSString with something like:
NSString *myString = [[NSString alloc] initWithData:postData encoding:NSUTF8StringEncoding];
and print that too, just to be on the safe side and, once you have make certain that you aren't sending the "token" parameter, start to debug the receiving end.
Hope this helps

Answer 2

It is a magic problem with a NSDictionary. When I send as NSMutableString - no problems.
NSMutableString *stringData = [[NSMutableString alloc] init];
[params enumerateKeysAndObjectsUsingBlock:^(id key, id value, BOOL *stop) {
[stringData appendString:[NSString stringWithFormat:#"%#=%#", key, value]];
[stringData appendString:[NSString stringWithFormat:#"&"]];
}];
NSData *postData = [stringData dataUsingEncoding:NSUTF8StringEncoding];
I don't know what happens and why :(