Updating height of UITableViewCell - ios

Question

I'm building a table that shows an entry for a user. One of the cells shows a set of "tags" downloaded from the server. I am currently building a set of UILabels and manually adding them to a view contained in the cell. While this works, the cell does not dynamically resize after adding the tags. The tags overlap the cell beneath it and I can't figure out how to manually update the height of the cell.
In cellForRowAtIndexPath:
JournalTagsCell *cell = [tableView dequeueReusableCellWithIdentifier:#"JournalTagsCell" forIndexPath:indexPath];
//Check if we have any tags to show
if(self.journalObject.journalEntryTags != nil){
cell.placeholderLabel.hidden = YES;
cell.tagsView = [self updateTagsView:cell.tagsView];
}
return cell;
The following is my method for actually creating each tag, laying them out and adding them to the view:
- (void)updateTagsView:(UIView*)viewToUpdate{
NSArray *items = self.journalObject.journalEntryTags;
//Clean up the view first
NSArray *viewsToRemove = [viewToUpdate subviews];
for (UIView *v in viewsToRemove) {
[v removeFromSuperview];
}
float x = 10;
float y = 10;
for (int i = 0; i < items.count; i++) {
CGRect textRect = [items[i] boundingRectWithSize:CGSizeMake(self.view.frame.size.width - 20, 1000)
options:NSStringDrawingUsesLineFragmentOrigin
attributes:#{NSFontAttributeName:[UIFont tagCopy]}
context:nil];
CGSize size = textRect.size;
if (x+size.width > (self.view.frame.size.width-20)) {
y += size.height + 10;
x = 10;
}
UILabel *lbl = [[UILabel alloc] initWithFrame:CGRectMake(x, y, size.width, size.height)];
lbl.userInteractionEnabled = YES;
[lbl setText:[NSString stringWithFormat:#" %# ", items[i]]];
[lbl setFont:[UIFont tagCopy]];
[lbl sizeToFit];
[lbl setTextColor:[UIColor colorWithRed:0.145 green:0.392 blue:0.576 alpha:1.000]];
[lbl setBackgroundColor:[UIColor colorWithRed:0.804 green:0.871 blue:0.914 alpha:1.000]];
lbl.layer.borderWidth = 1;
lbl.layer.borderColor = [UIColor colorWithRed:0.145 green:0.392 blue:0.576 alpha:1.000].CGColor;
lbl.layer.cornerRadius = 5;
[lbl.layer setMasksToBounds:YES];
[viewToUpdate addSubview:lbl];
UITapGestureRecognizer *tapGesture =
[[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(userClickedOnTag:)];
[lbl addGestureRecognizer:tapGesture];
x += size.width + 10;
if (x > (self.view.frame.size.width-20)) {
y += size.height + 10;
x = 10;
}
if (i == items.count-1) {
y+= size.height + 20;
}
}
[viewToUpdate setFrame:CGRectMake(0, 0, self.view.frame.size.width, y)];
}
However, I don't know how to manually update the height for this cell based on the size of this view. I don't want/need to manually calculate the height of every single cell, just this one which is why I'm not currently using heightForRowAtIndexPath but I don't know how to update the height of this one cell. Obviously I can calculate the height I need for this cell if necessary as I'm already setting up the view frame that holds the tags, but short of having to go through every single cell and manually calculate each ones height, I'm stumped.

Answer 1

I think you will have to use heightForRowAtIndexPath. I'm not sure you completely understand what's happening. Or maybe I have it wrong.. Either way, how I understand it: The total height of the "cell" will always be presented. You never set the "height" of the cell, it will automatically show the entire content. heightForRowAtIndexPath is not a way to tell the cell how tall it should be, but rather how much space the tableView should reserve for that particular cell. If you pass a height too short, it will still present the entire cell, but the next cell will start too soon. It also works the other way around, if you pass a bigger number than necessary, it will look like the cells are bigger, even though the cells aren't. It's just the tableView's representation.

Answer 2

If you are using iOS 8 you can use UITableViewAutomaticDimension.You can check out this example
self.tableView.rowHeight = UITableViewAutomaticDimension;
You can take a look also on this video : What's New in Table and Collection Views in the 2014 WWDC.

Answer 3

You can solve the issue with a variable for that row's height. In viewDidLoad() store default cell height to the variable. then while you calculate the height for the view store the view's height to the variable and to reload that cell use below method for the tableview by passing single cell's indexpath in array.
- (void)reloadRowsAtIndexPaths:(NSArray *)indexPaths withRowAnimation:(UITableViewRowAnimation)animation
It will update cell at particular index by calling all lifecycle method of a cell.
Make sure you return default value for all other cell in heightForRowAtIndexPath() except the cell with tagsView with calculated height cell.
-(CGFloat)tableView:(UITableView *)myTableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
{
if(indexpath.row == TAGSVIEW_ROWINDEX)
return calculated_height_value;
return default_row_height;
}
If the Cell with tagsView is not predefined with rowIndex, you can also store that rowIndex in one integer variable in cellForRowAtIndexPath().