Access to delegate methods of UIViews in UICollectionViewReusableView header

Question

Making a header in a UICollectionView is turning out to be much harder then in a table.

I subclassed the UICollectionViewReusableView, registered it's class in the UICollectionView, implemented collectionView:(UICollectionView *)collectionView viewForSupplementaryElementOfKind:(NSString *)kind atIndexPath:(NSIndexPath *)indexPath. In my header view I have two UITextField's and one UITextView. I need to have access to their delegate methods (editing began, finished...). Using this example I saw that you can do:

UICollectionReusableView *footer = (UICollectionReusableView*)[self.collectionView viewWithTag:999];
UILabel *footerLabel = (UILabel*)[footer viewWithTag:100];

But creating that many variables for every delegate method seems wrong. I need to be able to set the text in those text fields and text view. Is there a better way of doing this?

//...viewDidLoad
UICollectionView *images = [[UICollectionView alloc]initWithFrame:self.view.bounds collectionViewLayout:layout];
[images registerClass:[ImagesCell class] forCellWithReuseIdentifier:@"cellIdentifier"];
[images registerClass:[HeaderView class] forSupplementaryViewOfKind:UICollectionElementKindSectionHeader withReuseIdentifier:@"headerView"];
//images data source and delegate

- (UICollectionReusableView *)collectionView:(UICollectionView *)collectionView viewForSupplementaryElementOfKind:(NSString *)kind atIndexPath:(NSIndexPath *)indexPath{
    if (kind == UICollectionElementKindSectionHeader) {
        HeaderView *headerView = [collectionView dequeueReusableSupplementaryViewOfKind:UICollectionElementKindSectionHeader withReuseIdentifier:@"headerView" forIndexPath:indexPath];
        if (!headerView)
            headerView = [[HeaderView alloc]initWithFrame:CGRectMake(0, 0, self.view.frame.size.width, 180)];
            headerView.delegate = self;
        return headerView;
    }
    return nil;
}

And then I use casting with the tags to get the view. Is there any other way to update the individual views inside the header?

UPDATE:

HeaderView.h

@protocol HeaderViewDelegate <NSObject>

- (void)headerView:(id)view didBeginEditingFullName:(UITextField *)fullNameTextField;
- (void)headerView:(id)view didEndEditingFullName:(UITextField *)fullNameTextField;
- (void)headerView:(id)view didBeginEditingBreed:(UITextField *)breedTextField;
- (void)headerView:(id)view didEndEditingBreed:(UITextField *)breedTextField;
- (void)headerView:(id)view didBeginEditingDescription:(UITextView *)descriptionTextView;
- (void)headerView:(id)view didEndEditingDescription:(UITextView *)descriptionTextView;

@end

@interface HeaderView : UICollectionReusableView {
    id <HeaderViewDelegate> delegate;
}
@property (nonatomic, weak) id <HeaderViewDelegate> delegate;

This is how I set up the HeaderView.h...had to use id instead of (HeaderView *) in the methods...I was getting an error.

This is what I had in my PersonalViewController.m page before:

- (void)textFieldDidBeginEditing:(UITextField *)textField{
    if (textField == _fullName) {

    }else if (....)
}

Now that _fullName is inside the supplementary view, I can't access it. This is what I was trying to get to...

Changing it to this:

- (void)headerView:(HeaderView *)view didBeginEditingFullName:(UITextField *)fullName{
    NSLog (@"here");
}

No log output. I set the delegates for the views in HeaderView.m. Dammit, what am I not getting here?

UPDATE:

HeaderView.h is the same as before. I added the textfield and textview delegates to it. HeaderView.m:

@implementation HeaderView

@synthesize delegate=_delegate;

- (id)initWithFrame:(CGRect)frame {
    self = [super initWithFrame:frame];
    if (self) {
        UITextField *fullName = [[UITextField alloc]initWithFrame:CGRectMake(5, 100, 120, 21)];
        fullName.tag = 4;
        fullName.delegate = self;
        _fullName = fullName;
        [self addSubview:_fullName];
    }
}

PersonalViewController.m is the same. viewForSupplementaryElementOfKind is still the same as before...setting headerView.delegate = self;. In it I'm calling

- (void)headerView:(HeaderView *)view didBeginEditingFullName:(UITextField *)fullName{
    NSLog(@"here");
}

Should I be calling it inside the HeaderView.m? I need to call it from PersonalViewController.m...

Answer 1

You must understand that reusable cells are destroyed and reinitialized each time you scroll off the cell.

I would create a subclass for your supplementary view (as you already did), making all texfields as properties (you did this too). Also i'd create a protocol for your custom supplementary cell like that:

@protocol HeaderViewDelegate <NSObject>
    -(void)headerView:(HeaderView*)view didBeginEditingFirstTextField:(UITextField*)firstTextField;
    -(void)headerView:(HeaderView*)view didBeginEditingSecondTextField:(UITextField*)secondTextField;
    -(void)headerView:(HeaderView*)view didBeginEditingTextView:(UITextView*)textView;
@end

and then implement a delegtion pattern:

headerView.delegate = self;

and so on.

Tip: If you want to distinguish cell's subviews and have an access to them by indexPath you still can use tags without any extra variables, simply init each tag on this formula:

tag = indexpath.hash + subviewIndex

subviewIndex - is just an order number that you set manually, it must be unique for each subview of your cell. (In your example first textfield is 1, second is 2, textview is 3).