Custom implementation of UICollectionViewCell makes cells invisible - ios

Question

For the sake of context I'm developing a calendar app with 3 different views. Day, Month and Year View.
In order to display the days I've decided to use a UICollectionView with a custom implementation of UICollectionViewCell (so that I'm able to customize the aspect of each cell).
On the init of my NSObject CtrlCalendar class I register 3 cell Classes like this:
//Used for the yearView
[self.grid registerClass:[CollectionViewCell class] forCellWithReuseIdentifier:#"monthCell"];
//Used for the monthView
[self.grid registerClass:[CollectionViewCell class] forC ellWithReuseIdentifier:#"dayCell"];
//Used for the dayView
[self.grid registerClass:[CollectionViewCell class] forCellWithReuseIdentifier:#"hourCell"];
Than, on collectionView:collectionView cellForItemAtIndexPath:indexPath I'm doing as follows:
CollectionViewCell *cell = nil;
if ([self.currentDisplayType isEqualToString:#"monthView"]) {
cell = [collectionView dequeueReusableCellWithReuseIdentifier:#"dayCell" forIndexPath:indexPath];
cell.backgroundColor = [UIColor grayColor];
self.month = [self.displayingViews get:indexPath.section];
if (indexPath.row + 1 >= self.month.firstWeekDay && indexPath.row + 1 < self.month.numberOfDays + (self.month.firstWeekDay)) {
NSDateComponents *tempDay = [self.calendar components:NSCalendarUnitDay fromDate:self.month.date];
cell.date = [self.dateHelper addToDate:self.month.date days:(int)(tempDay.day + indexPath.row - self.month.firstWeekDay)];
cell.cellTitle.text = [NSString stringWithFormat:#"%i", (int)(tempDay.day + indexPath.row + 1 - self.month.firstWeekDay)];
cell.cellTitle.textColor = [UIColor blackColor];
if ([[self.dateHelper addToDate:self.month.date days:(indexPath.row + 1 - self.month.firstWeekDay)] isEqualToDate:self.today]) {
cell.cellTitle.textColor = [UIColor redColor];
}
cell.userInteractionEnabled = YES;
cell.separator.hidden = NO;
cell.contentView.hidden = NO;
} else {
cell.userInteractionEnabled = NO;
}
And finally here is my implementation of CollectionViewCell:
#interface CollectionViewCell ()
#property (nonatomic, retain) UILabel *cellTitle;
#property (nonatomic, retain) NSString *titleText;
#property (nonatomic, retain) UILabel *separator;
#property (nonatomic, retain) NSDate *date;
#end
#implementation CollectionViewCell
#synthesize cellTitle;
#synthesize titleText;
#synthesize separator;
#synthesize date;
- (void)dealloc {
[cellTitle release];
[titleText release];
[separator release];
[date release];
[super dealloc];
}
- (instancetype)initWithFrame:(CGRect)frame {
if (self = [super initWithFrame:frame]) {
self.cellTitle = [[[UILabel alloc] initWithFrame:self.bounds] autorelease];
self.cellTitle.textColor = [UIColor blackColor];
self.cellTitle.textAlignment = NSTextAlignmentCenter;
self.separator = [[[UILabel alloc] initWithFrame:CGRectMake(0, (self.frame.size.height - 0.25), self.frame.size.width, 0.5)] autorelease];
self.separator.backgroundColor = [UIColor lightGrayColor];
[self.contentView addSubview:self.separator];
[self.contentView addSubview:self.cellTitle];
}
return self;
}
- (void)prepareForReuse {
[super prepareForReuse];
self.cellTitle.text = nil;
self.separator.hidden = YES;
[self.cellTitle setTextColor:[UIColor blackColor]];
//the presence of this line is explained after the edit bellow
[self.subviews makeObjectsPerformSelector:#selector(removeFromSuperview)];
}
#end
The first time I run the app, the Month View is configured as expected, but as soon as it performs the dequeue, the cells turn blank.
After some debugging I found that the CollectionViewCell's cellTitle property is correctly set. The problem resides in the fact that after the dequeue the labels are hidden for some reason.
I know this is long question, but if you can help in anyway or know someone who can help please let me know!
Thanks a lot!
For clarification of what the problem is I'm adding some screens
Before scrolling:
After scrolling:
UPDATE 1
As #Alessandro Chiarotto answered, the
[self.subviews makeObjectsPerformSelector:#selector(removeFromSuperview)]
does make the cells empty. The caveat here is that I need that selector to remove from the cells some UILabels I'm adding to the yearView.
My yearView UICollection has 12 cells (one for each month). Each cell than has the number of UILabels as the days in each month. I'm adding this UILabels from the collectionView:collectionView cellForItemAtIndexPath:indexPath like this:
for (int d = 1; d < self.month.numberOfDays; d++) {
UILabel *day = [[[UILabel alloc] initWithFrame:dayRect] autorelease];
day.text = currentDay;
[cell addSubview:day];
}
If i don't perform the selector in prepareForReuse, after scrolling the view I have all the day labels in duplicate in each month cell.

Answer 1

If you scroll the collection then prepareForReuse will be called. In prepareForReuse you have the following call:
[self.subviews makeObjectsPerformSelector:#selector(removeFromSuperview)];
this will remove all the subviews of the cell (UILabel and so on).
At this point your cell will "white"...

Answer 2

I've found the problem. As #Alessandro said in his answer the [self.subviews makeObjectsPerformSelector:#selector(removeFromSuperview)]; was removing everything from the cell, therefore making it blank.
That would be it if it weren't for another aspect of the problem.
As I said in my question Update, I need that selector in order to remove some UILabels that are being added in the yearView. Those labels are the days in each month cell.
Solution:
I added a UIView property to the CollectionViewCell that has a frame equal to the cell's bounds. I than add the UILabels to this view and on the prepareForReuse I perform the removeFromSuperView on the self.labelsView.subviews. It works like a charm.
The correct implementation of prepareForReuse would be:
- (void)prepareForReuse {
[super prepareForReuse];
self.cellTitle.text = nil;
self.separator.hidden = YES;
[self.cellTitle setTextColor:[UIColor blackColor]];
[self.labelsView.subviews makeObjectsPerformSelector:#selector(removeFromSuperview)];
}