ViewDidLoad keeps getting called on UIPageViewController

Question

Im trying to make a UIPageViewController with a UITableViewController within.

Im having trouble getting the UIPageViewController to work properly. ViewDidLoad keeps getting called and the view never shows on my iOS Simulator.

Here are my classes:

ProgramViewController.h:

#import <UIKit/UIKit.h>
#import "TableViewController.h"

@interface ProgramViewController : UIPageViewController <UIPageViewControllerDataSource>
{
    UIPageViewController *programViewController;
    NSArray *pageContent;

}
@property (strong, nonatomic) UIPageViewController *programViewController;
@property (strong, nonatomic) NSArray *pageContent;
@property (strong, nonatomic) NSArray *listArray;
@property (strong, nonatomic) NSArray *pageTitles;

ProgramViewController.m

#import "ProgramViewController.h"

@implementation ProgramViewController
@synthesize programViewController,pageContent;

- (void)viewDidLoad
{
    [super viewDidLoad];
    NSLog(@"ViewDidLoad");

    _pageTitles = @[@"page0", @"page1", @"page2"];

    self.programViewController = [self.storyboard instantiateViewControllerWithIdentifier:@"2"];
    self.programViewController.dataSource = self;

    TableViewController *startingViewController = [self viewControllerAtIndex:0];
    NSLog(@"description = %@",[startingViewController description]);
    NSArray *viewControllers = @[startingViewController];
    [self.programViewController setViewControllers:viewControllers direction:UIPageViewControllerNavigationDirectionForward animated:NO completion:nil];

    // Change the size of page view controller
    self.programViewController.view.frame = CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height - 30);

    [self addChildViewController:programViewController];
    [self.view addSubview:programViewController.view];
    [self.programViewController didMoveToParentViewController:self];
}


#pragma mark - Page View Controller Data Source

- (UIViewController *)pageViewController:(UIPageViewController *)pageViewController viewControllerBeforeViewController:(UIViewController *)viewController
{
    NSUInteger index = ((TableViewController*) viewController).pageIndex;

    if ((index == 0) || (index == NSNotFound)) {
        return nil;
    }

    index--;
    return [self viewControllerAtIndex:index];
}

- (UIViewController *)pageViewController:(UIPageViewController *)pageViewController viewControllerAfterViewController:(UIViewController *)viewController
{
    NSUInteger index = ((TableViewController*) viewController).pageIndex;

    if (index == NSNotFound) {
        return nil;
    }

    index++;
    if (index == [self.pageTitles count]) {
        return nil;
    }
    return [self viewControllerAtIndex:index];
}

- (TableViewController *)viewControllerAtIndex:(NSUInteger)index
{
    if (([self.pageTitles count] == 0) || (index >= [self.pageTitles count])) {
        return nil;
    }
    NSLog(@"description = %d",[self.pageTitles count]);

    // Create a new view controller and pass suitable data.
    TableViewController *tableViewController = [self.storyboard instantiateViewControllerWithIdentifier:@"2.0"];
    tableViewController.titleText = self.pageTitles[index];
    tableViewController.pageIndex = index;

    return tableViewController;
}

- (NSInteger)presentationCountForPageViewController:(UIPageViewController *)pageViewController
{
    return [self.pageTitles count];
}

- (NSInteger)presentationIndexForPageViewController:(UIPageViewController *)pageViewController
{
    return 0;
}

And then i have the UITableViewController class. This class works perfectly when i use it by itself, but i dont know if is a problem of trying to put a UITableViewController inside a UIPageViewController:

TableViewController.h

#import <UIKit/UIKit.h>

@interface TableViewController : UITableViewController <UITableViewDataSource, UITableViewDelegate>
@property (strong, nonatomic) IBOutlet UITableView *tableView;
@property NSUInteger pageIndex;
@property NSString *titleText;

@end

TableViewController.m

#import "TableViewController.h"
#import "ProgramCell.h"

@implementation TableViewController
{
    NSArray *arrayDays;
}
- (void)viewDidLoad
{
    [super viewDidLoad];
    // Initialize table data
    for(int i=0;i<10;i++){

    }
    arrayDays = [NSArray arrayWithObjects:@"Egg Benedict", @"Mushroom Risotto", @"Full Breakfast", @"Hamburger", @"Ham and Egg Sandwich", @"Creme Brelee", @"White Chocolate Donut", @"Starbucks Coffee", @"Vegetable Curry", @"Instant Noodle with Egg", @"Noodle with BBQ Pork", @"Japanese Noodle with Pork", @"Green Tea", @"Thai Shrimp Cake", @"Angry Birds Cake", @"Ham and Cheese Panini", nil];
}

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

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    NSLog(@"description = %d",[arrayDays count]);
    return [arrayDays count];
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString *simpleTableIdentifier = @"CustomCell";

    ProgramCell *cell = [tableView dequeueReusableCellWithIdentifier:simpleTableIdentifier];
    NSLog(@"description = %@",[cell description]);

    if (cell == nil) {
        NSLog(@"cell nil");
        cell = [[ProgramCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:simpleTableIdentifier];
    }
    cell.durationLabelCell.text = @"HOLA";


    return cell;
}
@end

On the Xcode console, i keep getting the result of the "NSLog(@'ViewDidLoad');" on my ProgramViewController.h. The app instantiates the ViewController as long as it has memory and then it crashes.

If someone has any idea why this is happening it would be great. Thanks

Answer 1

IMP: Your ProgramViewController class has a variable (and property) named programViewController so the following explanation may sound confusing. To make it easier, I will mention the class in bold : ProgramViewController (with a capital P) and the variable in normal font : programViewController (with small p).

---

This line of code in your viewDidLoad :

self.programViewController = [self.storyboard instantiateViewControllerWithIdentifier:@"2"];

instantiates a new page view controller from storyboard and which you later add to the ProgramViewController .

If the view controller with identifier 2 in your storyboard is also a ProgramViewController (which I suspect is the case), you are creating a recurrence. Every time a ProgramViewController is added and in turn creates a new one in viewDidLoad .

You do not need another programViewController variable within your ProgramViewController class. Delete that variable and the property. Call setViewControllers on with self instead of self.programViewController and delete all the lines where you add the programViewController as a child view and controller.