Question

I’m a newbie programming iOS and I’ve a problem adding a new cell to a UITableView object. I’m using an storyboard and one of the scenes is a UIViewController that has several subviews: textfields, a tableview, etc. I intend to add rows to this tableView from a detail scene.

I’m able to initially add rows to the table, but I’m not able to add a row afterwards. When I press a button to add the row I call the method ‘[self.stepsListTableView reloadData];’ which produces a call to the method ‘- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section’ and it returns a correct value, including the new array element. But method ‘- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath’ is not called to update the table.

I do not understand what I’m doing wrong.

Details of my source code:

WorkoutDetailsViewController.h

(…)
@interface WorkoutDetailsViewController : UIViewController <StepDetailsViewControllerDelegate, UITextFieldDelegate, UITableViewDelegate, UITableViewDataSource>

@property (nonatomic, weak) id <WorkoutDetailsViewControllerDelegate> delegate;
@property (nonatomic, strong) Workout *workout;
(…)
@property (nonatomic, retain) IBOutlet UITableView *stepsListTableView;
(…)

WorkoutDetailsViewController.m

(…)
@synthesize stepsListTableView;
(…)
- (void)viewDidLoad
{
    [super viewDidLoad];

    addButton.enabled = FALSE;

    workoutNameField.delegate = self;
    if (self.workout == nil) {
        self.workout = [[Workout alloc] init];  
        self.stepsListTableView = [[UITableView alloc] init];
    }  
    self.stepsListTableView.delegate = self;
    self.stepsListTableView.dataSource = self;

}

(…)

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

// Customize the number of rows in the table view.
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section 
{
    //return [self.workout.stepsList count];
    NSInteger counter = 0;
    counter = [self.workout.stepsList count];
    return counter;
}

// Customize the appearance of table view cells.
- (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];
    }
    // Set up the cell...
    // Pending

    return cell;
}

- (void)stepDetailsViewControllerDidDone:(StepDetailsViewController *)controller
{
    [self.workout.stepsList addObject:controller.step];
    NSInteger counter = [self.workout.stepsList count];

    [self.stepsListTableView beginUpdates];

    NSArray *paths = [NSArray arrayWithObject:[NSIndexPath indexPathForRow:(counter-1) inSection:0]];
    [self.stepsListTableView insertRowsAtIndexPaths:paths withRowAnimation:UITableViewRowAnimationTop];

    [self.stepsListTableView endUpdates];

    [self.stepsListTableView reloadData];
}

(…)

Also in the storyboard, I have setup the outlets delegate and dataSource to be the controller view.

Any idea ?

Regards,
JoanBa

Answer 1

I have solved the issue. I have discovered using debugger that method reloadData was called for a different UITableView than the one initialized in viewDidLoad.

I reviewed the UITableView settings in storyboard, which aparently were correct but I have deleted them and created again. Now it works.

In UIViewController header I have the line

@property (nonatomic, retain) IBOutlet UITableView *stepsListTableView;

and in implementation I have commented lines

//self.stepsListTableView.delegate = self;
//self.stepsListTableView.dataSource = self;

And, of course, in storyboard I have defined for the UITableView the following relationships:

Outlets: dataSource, delegate –> UIViewController

Referencing outlet: UITableView –> UIVIewController

That’s it !!