Question

I have a class with two NSString data members

Header file

@interface WebSiteFavorites : NSObject

@property (strong, nonatomic) NSString *titleName;
@property (strong, nonatomic) NSString *url;`

- (id) initWithTitleName: (NSString *)titleName url: (NSString *)url;

@end

I have a TVC that uses this class as its data source, and I have hard coded some instances of my class in the appDelegate to populate the TV which works. From the TV i have a add button with a modal transition to a VC. In this view controller I have two text fields where the user enters a name and a url and then I using protocols and delegate to update the TVC (which i don’t quite understand). My problem is that after the entering the required info in the text fields my class instance is null.

Here is my code for this

Header
@interface WebSiteFavoritesAddFavoritesViewController : UIViewController

@property (strong, nonatomic) WebSiteFavorites *favorites;

@property (weak, nonatomic) IBOutlet UITextField *titleTextField;
@property (weak, nonatomic) IBOutlet UITextField *urlTextField;

@property (strong) id<WebSiteFavoritesDelegate> delegate;

- (IBAction)titleTextFieldChanged;
- (IBAction)urlTextFieldChanged;

- (IBAction)doneButtonTapped:(id)sender;
- (IBAction)cancelButtonTapped:(id)sender;

@end

Implementation

@implementation WebSiteFavoritesAddFavoritesViewController

@synthesize favorites = _favorites;
@synthesize urlTextField = _urlTextField;
@synthesize titleTextField = _titleTextField;


- (IBAction)titleTextFieldChanged
{
    self.favorites.titleName = self.titleTextField.text;

}

- (IBAction)urlTextFieldChanged
{
   self.favorites.url = self.urlTextField.text;

}

- (IBAction)doneButtonTapped:(id)sender
{  
    [self.delegate newFavoriteAdded:self.favorites];
    [self dismissModalViewControllerAnimated:YES];
}

- (IBAction)cancelButtonTapped:(id)sender
{
    [self dismissModalViewControllerAnimated:YES];
}

#pragma mark UITextFieldDelegate
- (BOOL)textFieldShouldReturn:(UITextField *)textField
{
    [textField resignFirstResponder];
    return YES;
}
@end

After the IBAction methods i have used break points and favorites is null.
Also I have some questions about protocols and delegates just for understanding. I have created a separate header file for my protocol, my TVC conforms to the protocol, in my VC i have created the delegate which you can see in my posted code. In my TVC i have implemented the function from my protocol. Is this the proper sequence?

Answer 1

You must instantiate favorites. Without instantiating objects don’t hold the values you assign to them.

So you must do…

favorites=[[WebSiteFavorites alloc] init];

or as you have another method initWithTitleName:url:, do use that to instantiate.

Hope this helps!