Unrecognized selector sent to instance in JSON parsing - ios

Question

Please help me debug this code
dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);
dispatch_async(queue, ^{
NSError *error = nil;
NSURL *urls = [NSURL URLWithString:[NSString stringWithFormat:#"http://cnapi.iconnectgroup.com/api/UserProfile?id=1"]];
NSString *json = [NSString stringWithContentsOfURL:urls encoding:NSASCIIStringEncoding error:&error];
NSLog(#"JSon data = %# and Error = %#", json, error);
if(!error)
{
NSData *jsonData = [json dataUsingEncoding:NSASCIIStringEncoding];
NSArray *myJsonArray = [NSJSONSerialization JSONObjectWithData:jsonData options:0 error:nil];
NSLog(#"JSON data is :: %#", myJsonArray);
for(NSDictionary *jsonDictionary in myJsonArray)
{
//NSString *uids = jsonDictionary[#"UID"];
NSString *address1 = jsonDictionary[#"Address1"];
NSString *address2 = jsonDictionary[#"Address2"];
NSString *city = jsonDictionary[#"City"];
NSString *emailId = jsonDictionary[#"EmailID"];
NSString *fname = jsonDictionary[#"FName"];
NSString *fax = jsonDictionary[#"Fax"];
NSString *lname = jsonDictionary[#"LName"];
NSString *password = jsonDictionary[#"Password"];
NSString *phone = jsonDictionary[#"Phone"];
NSString *state = jsonDictionary[#"State"];
NSString *uids = [jsonDictionary objectForKey:#"UID"];
NSString *zip = jsonDictionary[#"Zip"];
NSString *company = jsonDictionary[#"company"];
NSString *department = jsonDictionary[#"department"];
NSLog(#"Uid is = %#", uids);
NSLog(#"First Name = %#", fname );
NSLog(#"Last Name = %#", lname);
NSLog(#"Company = %#", company);
NSLog(#"Email Id = %#", emailId);
NSLog(#"Password = %#", password);
NSLog(#"Department = %#", department);
NSLog(#"Address 1 = %#", address1);
NSLog(#"Address 2 = %#", address2);
NSLog(#"City = %#", city);
NSLog(#"State = %#", state);
NSLog(#"Zip = %#", zip);
NSLog(#"Phone = %#", phone);
NSLog(#"Fax = %#", fax);
}
}
});
[activity stopAnimating];
self.activity.hidden = YES;
}
Image will give you where the error is. I get this error after clicking stepover to debug. I also tried
NSString *address1 = [jsonDictionary objectForKey:#"Address1"];

Answer 1

From the output of url, it shows it's not array but a dictionary. You are trying to convert to array here.
NSArray *myJsonArray = [NSJSONSerialization JSONObjectWithData:jsonData options:0 error:nil];
instead use this
NSDictionary *myJsonDictionary = [NSJSONSerialization JSONObjectWithData:jsonData options:0 error:nil];
then remove that for loop no need of it. and replace your variable jsonDictionary with myJsonDictionary so to retrieve values.
// for(NSDictionary *jsonDictionary in myJsonArray)
Run now it will be fine. Worked for me fine
If the output was array of Dictionaries it would have been looked like this with square brackets around.
For Ex: [{"id": "1", "name":"Aaa"}, {"id": "2", "name":"Bbb"}]
If you are not sure of nature of response from url you can check for
the type. For ex:
id jsonObject = [NSJSONSerialization JSONObjectWithData:jsonData options:0 error:nil];
if ([jsonObject isKindOfClass:[NSArray class]]) {
NSLog(#"its an array!");
NSArray *myJsonArray = (NSArray *)jsonObject;
// Handle Array of Dictionary
for(NSDictionary *jsonDictionary in myJsonArray)
{
NSString *address1 = jsonDictionary[#"Address1"];
//and so on
}
}
else {
NSLog(#"It's Dictionary");
NSDictionary *jsonDictionary = (NSDictionary *)jsonObject;
NSLog(#"jsonDictionary - %#",jsonDictionary);
//Handle NSDictionary
}

Answer 2

jsonDictonary is a NSString not as you expect NSDictonary.
Double check your JSON and maybe before calling that function check if it's NSDictonary.

Answer 3

Your should use one of the semi-standard frameworks for parsing JSON into Core Data. There are some SO questions about those.
In this case, your JSON has only one object which is not an array.
In general, your app shouldn't abort if server sent something unexpected, so it's better to use a parser which will loudly complain about malformed JSON than with it from scratch.