Question

After a ASIFormDataRequest , i create a temporary NSMutableArray *resultArray from the JSON then add it to a defined NSMutablearray *myData

-(void)viewDidLoad{
    myData = [[NSMutableArray alloc] init];
    //request that calls gotInfo method
}

-(void)gotInfo:(ASIFormDataRequest *)request{
    NSString *responseString = [request responseString];
    NSMutableArray *resultArray = [responseString yajl_JSON];
    [myData addObject:resultArray];
}

-(IBAction)doSomethingWithData:(id)sender{
    //something with myData
}

but when i try to call myData from outside of the gotInfo: method, i get bad access errors and when i inspect myData outside of the method, it shows a kern_protection_failure. So i’m guessing that outside of the method, the resultArray is obviously released, but it’s also released from myData since the object inside myData is sharing the same memory location?
I also tried

-(void)gotInfo:(ASIFormDataRequest *)request{
    NSString *responseString = [request responseString];
    [myData addObject:[responseString yajl_JSON]];
}

How do I preserve myData??

in my header file:

#import <UIKit/UIKit.h>

@class ASIFormDataRequest;

@interface EventsTableController : UITableViewController <UITableViewDataSource>{
    NSMutableArray *myData;
}
-(void)gotInfo:(ASIFormDataRequest *)request;

UPDATE:

so in the gbd, the myData is allocated as 0x5e96560 so i did

po 0x5e96560

and then i get the EXC_BAD_ACCESS with the reason being KERN_PROTECTION_FAILURE at address: 0x00000009

but if i do

po [[0x5e96560 objectAtIndex:0] objectForKey:@"key"]

then i get the value! whyyyyyy?

Answer 1

@property(nonatomic,retain) NSMutableArray *myData 

and create the object

self.myData = [[NSMutableArray alloc] init];

and

// and i assume your resultArray is a mature NSMutableArray object
[self.myData addObject:resultArray];

The best way of using copy I can think of, is to always set NSString properties to “copy” instead of retain. That way you get more accurate readings from the Leaks instrument if you mess up and forget to release a string an object is holding onto. Other uses of copy need to be more carefully thought out.

NOTE : You are responsible to release myData after no use of that variable.