'NSInvalidArgumentException', reason: '-[SBJsonParser objectWithString:error:]: unrecognized selector sent to instance 0x6695330' - iphone

Question

While creating a login view on my iphone app, I ran into this error:
'NSInvalidArgumentException', reason: '-[SBJsonParser objectWithString:error:]:
unrecognized selector sent to instance 0x6695330'
It's coming from this line:
NSDictionary *results = [parser objectWithString:json_string error:nil];
From this method:
+ (BOOL)loginWithUsername:(NSString *)username password:(NSString *)password
{
NSString *urlString = [NSString stringWithFormat:#"%#login3", ROSE_ROOT_URL];
NSURL *url = [NSURL URLWithString:urlString];
NSString *requestString = [NSString stringWithFormat:#"&mobile=1&username=%#&password=%#", username, password];
NSMutableURLRequest *request = [[NSMutableURLRequest alloc] initWithURL:url];
[request setHTTPMethod:#"POST"];
[request setHTTPBody:[NSData dataWithBytes:[requestString UTF8String] length:[requestString length]]];
NSData *response = [NSURLConnection sendSynchronousRequest:request returningResponse:nil error:nil];
NSString *json_string = [[NSString alloc] initWithData:response encoding:NSUTF8StringEncoding];
[request release];
// parse the JSON response into an object
// Here we're using NSArray since we're parsing an array of JSON product objects
SBJsonParser *parser = [[SBJsonParser alloc] init];
NSDictionary *results = [parser objectWithString:json_string error:nil];
[json_string release];
[parser release];
// NSDictionary *results = [RoseFetcher fetch:request];
// [request release];
if ([[results objectForKey:#"password"] intValue] == 0)
return NO;
return YES;
}
Any help or explanation would be greatly appreciated.

Answer 1

According to the documentation for SBJsonParser, it doesn't have a method called -objectWithString:error: - an opinion that's corroborated by your findings at runtime. Try sending it a message it will respond to, like -objectWithString:.