TableViewController data is empty in cellForRowAtIndexPath

Question

• I am very new to iOS programming
• I am trying to fetch data from Yelp's API and present that in UITableViewCell
• My code looks like

@interface SearchResultViewController ()
@property(nonatomic, strong) YelpClient *client;
@property(weak, nonatomic) IBOutlet UITableView *searchResultTableView;
@property(strong, nonatomic) NSArray *businesses;
@end

@implementation SearchResultViewController

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil {
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self) {
        NSLog(@"fetching businesses");
        [self fetchBusinesses];

    }
    return self;
}

- (void)fetchBusinesses {
    // You can register for Yelp API keys here: http://www.yelp.com/developers/manage_api_keys
    self.client = [[YelpClient alloc] initWithConsumerKey:kYelpConsumerKey

consumerSecret:kYelpConsumerSecret accessToken:kYelpToken accessSecret:kYelpTokenSecret];

    [self.client searchWithTerm:@"Thai" success:^(AFHTTPRequestOperation *operation, id response) {
        self.businesses = response[@"businesses"];
        [self.searchResultTableView reloadData];
        NSLog(@"businesses count (after fetch): %d", self.businesses.count);
    }                   failure:^(AFHTTPRequestOperation *operation, NSError *error) {
        NSLog(@"error: %@", [error description]);
    }];
}

- (void)viewDidLoad {
    [super viewDidLoad];

    self.searchResultTableView.dataSource = self;
    self.searchResultTableView.delegate = self;

    UITableViewController *uiTableViewController = [[UITableViewController alloc] init];
    uiTableViewController.tableView = _searchResultTableView;

    NSLog(@"view loaded");
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
    return 5;
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
    RestaurantViewCell *restaurantViewCell = [tableView dequeueReusableCellWithIdentifier:@"RestaurantViewCell"];
    if (restaurantViewCell == nil) {
        restaurantViewCell = [[RestaurantViewCell alloc] initWithStyle:UITableViewCellStyleDefault

reuseIdentifier:@"RestaurantViewCell"]; }

    NSLog(@"businesses count (for cell view): %d", self.businesses.count);
    restaurantViewCell.textLabel.text = @"Osha's Thai";
    return restaurantViewCell;
}
@end

When I run my application, I see the following in log

2014-06-19 09:51:57.447 yelp[15415:70b] fetching businesses
2014-06-19 09:51:57.483 yelp[15415:70b] view loaded
2014-06-19 09:51:57.485 yelp[15415:70b] businesses count (for cell view): 0
2014-06-19 09:51:57.486 yelp[15415:70b] businesses count (for cell view): 0
2014-06-19 09:51:57.487 yelp[15415:70b] businesses count (for cell view): 0
2014-06-19 09:51:57.487 yelp[15415:70b] businesses count (for cell view): 0
2014-06-19 09:51:57.487 yelp[15415:70b] businesses count (for cell view): 0
2014-06-19 09:51:57.900 yelp[15415:70b] businesses count (after fetch): 20

Questions - It seems that fetching data is asynchronous, so I get last line as

2014-06-19 09:51:57.900 yelp[15415:70b] businesses count (after fetch): 20

• But meanwhile cellForRowAtIndexPath is already called and the data is nil

How do I handle this situation to make sure that cellForRowAtIndexPath is called when we have data?

• I am also using [self.searchResultTableView reloadData]; but not sure if that is doing right thing

Answer 1

cellForRowAtIndexPath is being called because you told the table that there are cells to display.

This...

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
    return 5;
}

Should be...

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