cellForRowAtIndexPath not called; sections returns 1 and rows returns 4

Question

After parsing JSON data in a Data class, I set the UIViewController's NSArray *headlines property in a fillArrays method of the same Data class. In the viewDidAppear method of my UIViewController, I call reloadData on my UITableView. numberOfSectionsInTableView fires and returns 1, then numberOfRowsInSection fires and returns an array count of 4 (for 4 strings in the array). However, control never gets to cellForRowAtIndexPath and I'm having the hardest time understanding why, especially since I have valid sections and rows. The cells are all visible.

I've added the UITableViewDataSource and UITableViewDelegate protocols to the UIViewController interface and set the UITableView's delegate and dataSource to self in viewDidLoad (which also is verified by the row and section count methods being called).

I'm wondering if it has something to with me reinitializing the UIViewController in Data.m in order to set its properties.

In Data.m:

- (void)fillArrays:(NSArray *)jsonObjs {
    NSLog(@"fillArrays");         
    HeadlinesRootViewController *hrvc = [[HeadlinesRootViewController alloc] init];
    hrvc.headlines = [self getJsonValuesForKey:@"headline" inArrayOfObjects:jsonObjs];
    [hrvc viewDidAppear:NO];
}

In ViewController.m:

- (void)viewDidLoad {
    [super viewDidLoad];
    NSLog(@"viewDidLoad");
    // Table view
    headlineTableView = [[UITableView alloc] initWithFrame:CGRectMake(0, 180, self.view.bounds.size.width, 300) style:UITableViewStylePlain];
    [headlineTableView setDelegate:self];
    [headlineTableView setDataSource:self];
    // Temporary
    self.headlines = [[NSMutableArray alloc] initWithObjects:@"headline1", @"headline2", @"headline3", @"headline4", nil];



    [self.view addSubview:headlineTableView];
    self.headlineTableView = headlineTableView;
    [headlineTableView release];
}
- (void)viewDidAppear:(BOOL)animated {
    [super viewDidAppear:animated];
    NSLog(@"viewdidappear");
    NSLog(@"headlines: %@", self.headlines); // Returns an array of 4 headlines
    if( [self.headlines count] != 0 ){
        [self.headlineTableView reloadData];
    }
}

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

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
    NSLog(@"numberOfRowsInSection: %d", [self.headlines count]);
    return [self.headlines count];
}

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

    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];

    if (cell == nil) {
        cell = [[[UITableViewCell alloc] initWithFrame:CGRectZero reuseIdentifier:CellIdentifier] autorelease];
    }

    cell.text = [[NSString alloc] initWithFormat:@"%@", [self.headlines objectAtIndex:indexPath.row]];

    return cell;
}

Answer 1

Check to make sure that the tableView delegate and dataSource are pointed to the viewController

Answer 2

I cannot see anything wrong with the code as-is, have you verified with breakpoints that cellForRow is never reached (even though I see you have a log statement)?

Also I would try just for a sanity check to return "1" explicitly in rowsInSection, and hardcode a string in the cell you are returning in cellForRow.

If all else fails, create a new table view controller from the XCode templates and put your calls in there - then when that works, work backwards to why your code does not.

Also, it would be good to see your viewDidLoad setup code (add to answer above please).

Answer 3

if you're setting the delegate and datasource at viewDidLoad, then that may be the source of your bug. Can you set the datasource and delegate in init?

Answer 4

In fillArrays, you create another view controller - but you never do anything with it or its view, you would never see that view. You would never call viewDidAppear manually either, that happens automatically when a view controllers view is displayed (ONLY in the context of a navigation controller though).

Normally the flow is, you create a view controller and either add that view as a subview of a current view, or push it as a new window via a navigation controller. I'm pretty sure your whole issue is that they table is never added to a view anyone actually sees, so the table calls the other methods but never calls cellForRow because its layoutSubviews code is simply not being called.

Answer 5

I am pretty new to Iphone dev . I am also facing same problem. But the interesting thing is when I write the same code on my Application's viewController.m then It works fine. But when I write the same code on BrowseList.m which is linked with BowseList.xib(a new view which will load on the click event of a button on viewcontroller.xib) then it dos not work. When I debug the code then I found that CellForRowAtIndexPath method is not called.

Now can any one help me in this issue.

Thanks in Advance.

Gaurav