Assigning data from an anonymous handler ios - objective-c

Question

I'm trying to get a reference of an NSArray that gets passed when I call sendAsyncrhonousRequest. Once I have that NSArray, I'd like to assign it to a class attribute but it seems I can't do that.
#implementation BarTableViewController {
NSArray *_jsonArray;
}
[NSURLConnection sendAsynchronousRequest:request
queue:[NSOperationQueue mainQueue]
completionHandler:^(NSURLResponse *response, NSData *data, NSError *error)
{
NSInteger statusCode = [(NSHTTPURLResponse *)response statusCode];
if (statusCode == 200 && data.length > 0 && error == nil)
{
NSError *e = nil;
NSArray *jsonArray = [NSJSONSerialization JSONObjectWithData: data options: NSJSONReadingMutableContainers error: &e];
if (!jsonArray) {
NSLog(#"Error parsing JSON: %#", e);
} else {
_jsonArray = jsonArray; // this doesn't work? _jsonArray is at the class level
}
}
else if (error)
{
NSLog(#"HTTP Status: %ld", (long)statusCode);
}
else if (statusCode != 200)
{
NSLog(#"HTTP Status: %ld", (long)statusCode);
}
}];
If I traverse jsonArray it will correctly display the data. If I assign it to _jsonArray to use it later, it no longer returns any data. The count of the array is zero.
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
return _jsonArray.count; // always returns zero
}
How can I assign jsonArray to a class attribute so that I can use that data later?

Answer 1

My theory was correct. The UI was loading before the request finished. What I did to fix this issue was to call
[self.tableView reloadData];
Inside the async request.

Answer 2

Forget simple assignment:
#implementation BarTableViewController {
// NSArray *_jsonArray; forget it
}
instead own the object.
#interface BarTableViewController()
#property(nonatomic, strong)NSArray *jsonArray;
#end
/* --------- */
#implementation BarTableViewController
#syntethise jsonArray = _jsonArray;
#end
then to make it own it
self.jsonArray = jsonArray; // will call synthesized setter
I'm assuming you are using ARC, because you get a nil value instead of a dangling pointer. Now you will get a valid jsonArray.