UITableview in UITableviewcontroller - cellforrowatindexpath not called on reload

Question

I am stucked in a stupid problem since two days. I have got a UITableViewController pushed in Navigation Controller. When it loads, since there is no data, so empty table is visible:

But when I receive data from server, and call [self.tableView reloadData], both numberOfRowsInSection and heightForRowAtIndexPath get invoke except cellForRowAtIndexPath and my controller is shown without table:

I can't really understand that why it is happening. All datasource methods are called except for cellForRowAtIndexPath. Please someone guide me... Thanks..

ActLogController.h

@interface ActLogController : UITableViewController<ASIHTTPRequestDelegate,UITableViewDataSource,UITableViewDelegate>

@property(strong) NSMutableArray *activityKeys;

@end

ActLogController.m

- (void)viewDidLoad
{
    [super viewDidLoad];

    activityKeys = [[NSMutableArray alloc] init];
    self.tableView.dataSource = self;
}

-(void) viewWillAppear:(BOOL)animated
{
    [super viewWillAppear:animated];
    [self retrieveActivityLogFromServer];
}

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

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

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

    if(cell == nil)
    {
        cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
    }
    // Configure the cell...
    ActivityLogUnit *act = [activityKeys objectAtIndex:indexPath.row];
    cell.textLabel.text = act.price;

    return cell;
}

-(CGFloat) tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
{
    return 50.0;
}

-(void) requestFinished:(ASIHTTPRequest *)request
{
    NSArray *list = [request.responseString JSONValue];

    for (int i = 0; i < list.count; i++) {

        NSArray *singleTrade = [[list objectAtIndex:i] JSONValue];

        ActivityLogUnit *unit = [[ActivityLogUnit alloc] init];

        unit.symbol = [singleTrade objectAtIndex:0];
        unit.type = [singleTrade objectAtIndex:1];
        unit.price = [singleTrade objectAtIndex:2];
        unit.volTraded = [singleTrade objectAtIndex:3];
        unit.remVol = [singleTrade objectAtIndex:4];
        unit.actualVol = [singleTrade objectAtIndex:5];
        unit.recordID = [singleTrade objectAtIndex:6];
        unit.orderNo = [singleTrade objectAtIndex:7];
        unit.time = [singleTrade objectAtIndex:8];

        [activityKeys addObject:unit];

    }

    if(activityKeys.count > 0)
    {
        [self.tableView reloadData];//it is called and I have got 6 items confirm
    }
}

EDIT

I set some dummy data in my array activityKeys, Data is being displayed in table, and cellforrowatindexpath is called successfully. But as I reload data after sometime, other methods are called except this one and table disappears as shown in 2nd pic. Any ideas?

Answer 1

Your problem is that you probably download the data content on a background thread. Since you cannot update the UI on a background you need to call [self.tableView reloadData] on the main thread once the download is finished!

Hope it helps!