Question

I am trying to load json into a uitableview. I have worked with json before but never used it with a tableview. I keep getting this error: -[__NSCFNumber count]: unrecognized selector sent to instance. I’m pretty sure it is because in the numberOfRowsInSection method im returning the count of the array. Please let me know how to fix this or if I am missing something and not seeing it.

Here is he code:
.h file

    @interface HistoryViewController : UITableViewController <UITableViewDataSource,                  UITableViewDelegate>
{
    NSArray *jsonData;
    NSMutableData *responseData;
}

.m file

- (void)viewDidLoad 
{       
responseData = [[NSMutableData data] retain];
NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:@"Json url"]];
[[NSURLConnection alloc] initWithRequest:request delegate:self ];


[super viewDidLoad];
}


- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response {
[responseData setLength:0];
}
- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data {
[responseData appendData:data];
}

- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error {
NSLog(@"Connection failed: %@", [error description]);
}

- (void)connectionDidFinishLoading:(NSURLConnection *)connection {
[connection release];

NSString *responseString = [[NSString alloc] initWithData:responseData encoding:NSUTF8StringEncoding];
[responseData release];

NSDictionary *dictionary = [responseString JSONValue];
NSArray *response = [dictionary objectForKey:@"name"];

jsonData = [[NSArray alloc] initWithArray:response];
}


- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
return 1;
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section 
{
return  jsonData.count;
}

- (UITableViewCell *)tableView:(UITableView *)tableView 
     cellForRowAtIndexPath:(NSIndexPath *)indexPath {

UITableViewCell *cell = [[UITableViewCell alloc]
                         initWithStyle:UITableViewCellStyleDefault
                         reuseIdentifier:@"cell"];


cell.textLabel.text = [jsonData objectAtIndex:indexPath.row];

return cell;
}

Answer 1

All right, I notice that your array is never initialized until the connectionDidFinishLoading method is run. The delegate methods for your data table are likely running before connectionDidFinishLoading, so you should initialize your jsonData array in viewDidLoad instead of connectionDidFinishLoading.

You can keep your connectionDidFinishLoading calls the same, but make sure you call reloadData on your data table at the end of the connectionDidFinishLoading method to fill out your data table with the downloaded data.