Question

Good day everyone! I would just want to ask what is wrong with what I am doing. I am working with this for two days and yet I still can’t make it. It says “unrecognized selector sent to instance 0x748b800”.
What I am doing is parsing a json returned value. Below is the sample json returned value:

{
   "data": [
      {
         "name": "John Patola",
         "id": "123444432"
      },
      {
         "name": "Joshua Valdez",
         "id": "22234567778"
      }
]
}

I want to store them in an array called
NSArray *storage.
Below are my codes:

-(void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data{
[self.rData appendData:data];
}
-(void)connection: (NSURLConnection *)connection didFailWithError:(NSError *)error{
[rData release];
[connection release];
}
-(void)connectionDidFinishLoading:(NSURLConnection *)connection{
NSString *myVar = [[[NSString alloc] initWithData:rData encoding:NSUTF8StringEncoding] autorelease];
NSArray *storage =[[(NSDictionary *)myVar objectForKey:@"data"]retain]; // this line seems to be the error
NSLog(@"%i", [storage count]);

When I run this code, I got an error “unrecognized selector sent to instance 0x748b800”. Do you think that the line I’ve marked really gives error? How can I fix it? Thank you for your help in advance. 😉

Answer 1

Add JSON kit in your project.

Declare a method in your viewController.h file

-(void)JsonParsing:(NSString *)string;

Then import

#import "SBJSON.h"
#import "JSON.h"

in your viewController.m file and

-(void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data
{
    [self.rData appendData:data];
}
-(void)connection: (NSURLConnection *)connection didFailWithError:(NSError *)error
{
    [rData release];
    [connection release];
}
-(void)connectionDidFinishLoading:(NSURLConnection *)connection
 {
    NSString *theXMLString = [[NSString alloc]initWithBytes:[self.rData mutableBytes] length:[self.rData length] encoding:NSUTF8StringEncoding];
    [self JsonParsing:theXMLString];
 }

Then parse your string here –

-(void)JsonParsing:(NSString *)string
{
    SBJSON *jsonObject = [[SBJSON alloc]init];
    NSArray *dataArray = [[NSArray alloc]init];
    dataArray = [jsonObject objectWithString:string];
    NSLog(@"%d", [dataArray count]);

}