ViewWillAppear on UITableViewCell?

Question

Is there any way to perform something like ViewWillAppear on UITableViewCell?

UITableViewDelegate methods (like willDisplayCell) only works when cells appear by scrolling.

In my situation, I need to detect cell appearance in a situation like user moves to another Tab and gets back to the UITableView.

I was able to solve the my problem using indexPathsForVisibleRows method but this doesn't seem to be a smart way of doing it.

Dichloride

What do you want to perform when user came back from another tab ? – Collazo

Answer 1

Yes. you have to use awakeFromNib meyhod inside the m file. this method is always call first.

-(void)awakeFromNib{

}

if visible cell not load then you have to reload your tableview.

 tableView.reloadData()

Hope it helps you.

Cymbal

Thanks for the answer but awakeFronNib is not called in a case like a user moves to another Tab and gets back to the UITableView. – Dichloride

@Dichloride awakeFromNib is called only when first of cell load like in UIViewController – Cymbal

@Dichloride one anothyer way to load previus tableview cell is reload your tableview when it clicks on another Tab – Cymbal

"calling tableView.reloadData() in the UITableView viewWillAppear" as Vvk Aghera suggested was a perfect solution. This should be an accepted answer. Great and very smart solution, thanks a lot. – Dichloride

I didn't realize tableView.reloadData() solution was on the answer, I just accepted the answer – Dichloride

Answer 2

I'm not sure whether this will work for you as you want to do something on tab change as well otherwise it will work.

I know I am answering too late, but I am answering to help others who view this post.

So you can try this: (Objective-C)

- (void)tableView:(UITableView *)tableView willDisplayCell:(UITableViewCell *)cell  
                                         forRowAtIndexPath:(NSIndexPath *)indexPath {
    // Do what ever you want
}

(Swift)

func tableView(tableView: UITableView, willDisplayCell cell: UITableViewCell, forRowAtIndexPath indexPath: NSIndexPath) {
    // Do what ever you want
}

Lavellelaven

I tried to use this method (swift) but I got an error to remove "override" -"Method does not override any method from its superclass". When I remove the "override" the app compiles but the method is not called, although other delegate methods are called (such as "didSelectRowAtIndexPath") – Alon

@Zvi, Thanks. Updated my answer. Can you try following method instead of willDisplayCell and let me know your result: func tableView(_ tableView: UITableView, willDisplay cell: UITableViewCell, forRowAt indexPath: IndexPath) – Lavellelaven

First need to use indexPath: NSIndexPath (mistake even in Apple documentation). Second, I do not know what I did but now it works, using willDisplayCell - willDisplay does still not working – Alon