Reloading UITableView Container from method

Question

I am trying to reload my tableview with the parameters received from changing a UIDatepicker. Currently I have the following method that captures the data and sends it to the UIButton (which works). I am trying to reset the container view that houses the UITableViewController which is called DisplayTableViewController but it is not reloading the NSFetchController. Any suggestions about how to debug or fix this issue?

-(void)changeDate:(UIDatePicker *)sender {

    //NSDate Formatter
    NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
    [dateFormatter setDateFormat:@"ddMMyyyy"];

    //Convert to string
    NSString *stringFromDate = [dateFormatter stringFromDate:sender.date];

    //Send to UIButton
    [dateLabel setTitle:stringFromDate forState:UIControlStateNormal];

    DisplayTableViewController *tbc = (DisplayTableViewController *)self.childViewControllers[0];
    [tbc.tableView reloadData];

}

---

EDIT

 if ([[segue identifier] isEqualToString:@"ShowDisplayResults"])
    {
        //Format Date for Seague
        NSDateFormatter *todaysdate = [[NSDateFormatter alloc] init];
        [todaysdate setDateFormat:@"ddMMyyyy"];
        //Convert to string for Seague
        NSString *stringFromDate = [todaysdate stringFromDate:[NSDate date]];
        // Store the text we entered to dateSeague
        dateSeague =stringFromDate;
        // Get reference to the destination view controller
        DisplayTableViewController *targetVC = [segue destinationViewController];
        // Pass any objects to the view controller here, like...
        targetVC.dateSeague = dateSeague;
        targetVC.Ex = self.Ex;

    }

NSFETCHCONTROLLER IN CONTAINER

- (NSFetchedResultsController *)fetchedResultsController {
    NSLog(@"Test Date for second seague = %@", dateSeague);
    if (_fetchedResultsController != nil) {
        return _fetchedResultsController;
    }
    NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
    //Query Entity
    NSEntityDescription *entity = [NSEntityDescription entityForName:@"WorkoutDetails"inManagedObjectContext:managedObjectContext];
    //Fetch Entity
    [fetchRequest setEntity:entity];

    //Sort Returned Values
    NSSortDescriptor *sort = [[NSSortDescriptor alloc] initWithKey:@"weight" ascending:NO];
    //Fetch Sorted Array
    [fetchRequest setSortDescriptors:[NSArray arrayWithObject:sort]];
    //Set Return Size
    [fetchRequest setFetchBatchSize:20];

    //Predicate Results Based on ID
    NSPredicate *sortName = [NSPredicate predicateWithFormat:@"exid == %@", Ex.name];
    //Get NSDate format from String
    NSString *stringFromDate = dateSeague;
    NSDateFormatter *df = [[NSDateFormatter alloc] init];
    //Convert Back to NSDate
    [df setDateFormat:@"ddMMyyyy"];
    NSDate *inputedDate = [df dateFromString: stringFromDate];
    //Set Predicate
    NSPredicate *sortDate = [NSPredicate predicateWithFormat:@"date == %@", inputedDate];
    //Compound Predicate Array
    NSPredicate *placesPredicate = [NSCompoundPredicate andPredicateWithSubpredicates:[NSArray arrayWithObjects:sortName, sortDate, nil]];
    //Fetch Predicate Compound Array
    [fetchRequest setPredicate:placesPredicate];
    //Continue Fetching!
    NSFetchedResultsController *theFetchedResultsController =
    [[NSFetchedResultsController alloc] initWithFetchRequest:fetchRequest
                                        managedObjectContext:managedObjectContext sectionNameKeyPath:nil
                                                   cacheName: nil];
    self.fetchedResultsController = theFetchedResultsController;
    _fetchedResultsController.delegate = self;

    return _fetchedResultsController;

}

Answer 1

First of all self.childViewControllers[0] will get you the first view controller on the view controller hierarchy and you want this only if you have one view controller that contains another view controller.

Second it's not a good practice to use this approach since you don't really know the state of the view controller when you call this and it's possible that the view controller at that index won't be the same class as you expected.

So I suggest that you implement a delegate for your view controller or view that holds the date picker and when the date is changed and you do all the things that you want to do with the date, call the delegate. If you don't want to do anything with the date, you just want to pass it to the view controller, then you can set the date picker delegate to be your DisplayTableViewController

As a side note, I don't know the hierarchy that you have right now and if you don't find my answer helpful please add more details to your question (the hierarchy and the flow that you want to get)

Answer 2

Are query params for the NSFetchRequest of the NSFetchController changing? If so, make sure that you use deleteCacheWithName if it is using a cache, and then reconfigure the NSFetchController.