Question

Just trying to understand my table isn’t being populated when my view controller appears here. I’m using AIHTTPRequest to communicated with a REST API. The call returns an array of associative arrays (which I’m assuming I’ll have to cast to an NSArray of NSDictionaries).

In the header of my TableViewController:

@interface MyTableViewController : UITableViewController <UITableViewDelegate, UITableViewDataSource> {
    NSArray *homepageItems;
}

@property (nonatomic, retain) NSArray * homepageItems;

In the implementation:

@synthesize homepageItems;
....
- (void)viewDidLoad {

NSURL *url = [NSURL URLWithString:URL_TO_MY_API];
ASIHTTPRequest *request = [ASIHTTPRequest requestWithURL:url];
[request setDelegate:self];
[request startAsynchronous];

When the data is returned:

- (void)requestFinished:(ASIHTTPRequest *)request
{
    // Use when fetching text data
    NSString *responseString = [request responseString];
    id response = [responseString objectFromJSONString];
    homepageItems = (NSArray *)response;
}

And in the Table View method:

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString *CellIdentifier = @"Cell";

    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
    if (cell == nil) {
        cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleValue2 reuseIdentifier:CellIdentifier] autorelease];
    }

    NSDictionary *dataItem = [homepageItems objectAtIndex:indexPath.row];

    // Configure the cell...
    cell.textLabel.text = [dataItem objectForKey:@"message"];

    return cell;
}

When the view loads nothing is in the table. I suspect this is happening because when the table view method is fired homepageItems hasn’t been populated by the asynchronous method. How can I achieve the data being loaded into the table view?

Thanks,

EDIT: In my requestFinished method, I’ve examined the homepageItems object by doing the following:

for(NSDictionary *dictionary in homepageMMDs) {
    NSLog(@"%@", [dictionary objectForKey:@"message"]);
}

And the proper messages from my API service are being logged.

Answer 1

You are not retaining the downloaded data:

Instead of:

- (void)requestFinished:(ASIHTTPRequest *)request
{
    // Use when fetching text data.
    NSString *responseString = [request responseString];
    id response = [responseString objectFromJSONString];
    homepageItems = (NSArray *)response;
}

You need to do: (crucially using self in front of homepageItems)

- (void)requestFinished:(ASIHTTPRequest *)request
{
    // Use when fetching text data.
    NSString *responseString = [request responseString];
    id response = [responseString objectFromJSONString];
    self.homepageItems = (NSArray *)response; 
    // and others have said you need to reload the tableView
    [self.tableView reloadData];
}