Create JSON string in iOS - ios

Question

How to create JSON string for HTTP Request in iOS
i have these values:
{"name":"customer6","pass":"customer6", "mail":"customer6#xy.com","user_roles":"5", "field_login_pin_value":{"und":[{"value":"2324"}]} }
So how to make JSON string out of this data ?
Here is my code :
NSArray *keys = [NSArray arrayWithObjects:#"name",#"pass",#"mail",#"user_roles",#"field_login_pin_value", nil];
NSArray *objects = [NSArray arrayWithObjects:#"customer6",#"customer6",#"customer6#xy.com",#"5",#"{\"und\":[{\"value\":\"2324\"}]", nil];
NSDictionary *jsonDictionary = [NSDictionary dictionaryWithObjects:objects forKeys:keys];
NSString *jsonString = [jsonDictionary JSONRepresentation];
NSData *jsonData = [jsonString dataUsingEncoding:NSUTF8StringEncoding];
NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:[NSURL URLWithString:#"http://xxxxxxxx/register.json"]];
[request setValue:#"application/json" forHTTPHeaderField:#"Content-Type"];
[request setValue:jsonString forHTTPHeaderField:#"json"];
[request setHTTPMethod:#"POST"];
[request setHTTPBody:jsonData];
nsconnection= [[NSURLConnection alloc] initWithRequest:request delegate:self];
When I hit the web-service request, I get the following response:
"form_errors" = {
"field_login_pin_value][und][0][value" = "PIN value field is required.";
};
}
I always get the same error
Can anyone let me know what is wrong with my implementation ?

Answer 1

I'd imagine that JSONRepresentation is formatting "{\"und\":[{\"value\":\"2324\"}]" as the literal string it is, not as a value within a dictionary within an array within a dictionary. You should make the whole dict-array-dict structure. This will all be easier if you use array and dictionary literals:
NSDictionary *jsonDictionary = #{
#"name" : #"customer6",
#"pass" : #"customer6",
#"mail" : #"customer6#xy.com",
#"user_roles" : #"5",
#"field_login_pin_value" : #{
#"und":#[
#{
#"value" : #"2324"
}
]
}
};
You can, of course, coalesce the pin_value value to a single line, this is just for clarity.