How can I get UITableViewCell object from a UIButton action method? - ios

Question

I have a UITableView in which I have added a UIButton as accessory view for each cell. Note that I set the tag of the button as current row for future use.
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
// Configure the cell...
if(cell == nil) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier];
cellButton = [UIButton buttonWithType:UIButtonTypeCustom];
cellButton.frame = CGRectMake(0, 0, 30, 30);
[cellButton setBackgroundImage:[UIImage imageNamed:#"cellButton.png"] forState:UIControlStateNormal];
[cellButton addTarget:self action:#selector(cellButtonAction:) forControlEvents:UIControlEventTouchUpInside];
cellButton.tag = indexPath.row; // <= Will use this in the next method
cell.accessoryView = cellButton;
}
//Load cell with row based data
return cell;
}
Now when one of these buttons is tapped, I need to make changes to the cell. So I implement cellButtonAction where I use the tag to get back the cell:
-(void)editCommentButtonAction:(id)sender
{
UIButton *button = sender;
NSIndexPath *indexPath = [NSIndexPath indexPathForRow:button.tag inSection:0];
UITableViewCell *cell = [self.tableView cellForRowAtIndexPath:indexPath];
[self makeChangesToCell:cell];
}
But this seems like a very round about way. Is there a cleaner way to do this?

Answer 1

So assuming that the button is in the contentView directly:
ask "sender" (ie the button) for its superview, which is the cell's contentView
ask that view for its superView, which is the cell
ask the tabview for the index of this cell:
- (NSIndexPath *)indexPathForCell:(UITableViewCell *)cell
EDIT: Actually, I use a general purpose method or function now that just walks up the superviews, looking for a view that is 'KindOf' a UITableViewCell or a UICollectionViewCell. Works like a champ!
The code in Swift:
func containingUITableViewCell(tableView: UITableView, var view: UIView) -> (UITableViewCell, NSIndexPath)? {
while let v = view.superview {
view = v
if view.isKindOfClass(UITableViewCell.self) {
if let cell = view as? UITableViewCell, let indexPath = tableView.indexPathForCell(cell) {
return (cell, indexPath)
} else {
return nil
}
}
}
return nil
}
func containingUICollectionViewCell(collectionView: UICollectionView, var view: UIView) -> (UICollectionViewCell, NSIndexPath)? {
while let v = view.superview {
view = v
if view.isKindOfClass(UICollectionViewCell.self) {
if let cell = view as? UICollectionViewCell, let indexPath = collectionView.indexPathForCell(cell) {
return (cell, indexPath)
} else {
return nil
}
}
}
return nil
}

Answer 2

You can do it in a easier way. You will get the table view cell using the sender parameter.
Check the following code.
-(void)editCommentButtonAction:(id)sender
{
UIButton *button = (UIButton *)sender;
UITableViewCell *cell = (UITableViewCell*)[button superview];
[self makeChangesToCell:cell];
}
Here,
You are casting the sender of type id to a UIButton
You are calling the getter superview of that button, it will give you the UITableViewCell
Doing your customization.

Answer 3

You can get the cell as follows.
-(void)editCommentButtonAction:(id)sender
{
NSIndexPath* indexPath = 0;
//Convert the bounds origin (0,0) to the tableView coordinate system
CGPoint localPoint = [self.tableView convertPoint:CGPointZero fromView:sender];
//Use the point to get the indexPath from the tableView itself.
indexPath = [self.tableView indexPathForRowAtPoint:localPoint];
//Here is the indexPath
UITableViewCell *cell = [self.tableView cellForRowAtIndexPath:indexPath];
[self makeChangesToCell:cell];
}

Answer 4

I had the same situation, the thing is that I had an imageView inside my tablecells, and I want to get the cell that holds the imageview that I tapped..
//MyCell is subclass of UITableViewCell
if ([[[[sender view] superview] superview] isKindOfClass:[MyCell class]]) {
MyCell *cell = (MyCell *)[[[sender view] superview] superview];
NSIndexPath *cellIndexPath = [myTable indexPathForCell:cell];
NSLog(#"cellIndexPath: %# - %#",cellIndexPath, [videoURLArray objectAtIndex:cellIndexPath.row]);
}
[sender view] - imageView
[[sender view] superview] -- where my imageView was placed (in this case, the superview of my imageView is the cell's contentView)
[[[sender view] superview] superview] --- where the contentView was placed -- the cell
The NSLog part should print the correct row and section of the tapped imageView.. Just Modify the code. ;)

Answer 5

Hello gigahari Use the following code.
- (void)cellStopDownloadButtonClicked:(id)sender
{
id viewType = [sender superview];
do {
viewType = [viewType superview];
}
while (![viewType isKindOfClass:[CustomCell class]] || !viewType);
CustomCell *cell = (CustomCell *)viewType;
// use the cell
}
This will work in all cases like ios 6 and ios 7. in ios 7 an extra view added in cell (content view).
if you use [[sender superview] superview] it will fail in some cases.

Answer 6

The way i usually do this:
cell stores the data for the given row or the index path
create a protocol with a method -didSelectSomething or -didSelectAtIndexPath:
the cell holds a reference to an instance of the protocol, which will be your datasource
wire the button action to the cell in your nib
have the cell call the delegate
DON'T FORGET to clean up the cell in prepareForReuse. Storing state in cells can lead to nasty bugs, so be sure to clean up on reuse.
The tag thing is a real hack, and it won't work if you have more than one section.
The sender superview will break if you reorder the views in your nib.
For this particular case (accessory view), isn't there a dedicated table delegate method?