[iPhone SDK] - reuseIdentifier with loadNibNamed

the reuse identifier is called identifier in the nib.

Table View Cell Attributes tab of the inspector, (when you have a UITableViewCell selected) first line

I have been starting at this problem for a couple of hours now and am starting to believe there is a Cocoa Touch bug that causes the cell to not be stored as a reusable cell if it was loaded from a nib instead of being alloc and init'ed. Anyone have a workaround?

You're thinking about this in the wrong way.
There are 2 pieces to this. As was said above, the first thing is make sure that in the Nib for the Cell you enter the identifier value. This ensures that the instance that's created with the Nib info has the right identifier.
The second piece is that you absolutely do NOT want the identifier to be anything other than a constant. The identifier specifies the pool from which you can take reusable cells and it makes no sense to change it. When you do the following

MyCustomCell *cell = (MyCustomCell *)[tableView dequeueReusableCellWithIdentifier:MyIdentifier];

it tries to pull a cell from the pool specified by MyIdentifier. That's it. If there's no previously cell tagged for reuse, it returns nil and then you recreate one using the following code:

 if (cell == nil) {
 NSArray * MyCustomCellNib = [[NSBundle mainBundle] loadNibNamed:@"MyCustomCell" owner:self options:nil];
 cell = (MyCustomCell *)[MyCustomCellNib objectAtIndex:1];
}

(which assumes you've created a nib called MyCustomCell.nib and the only thing in it apart from First Responder and File's Owner is your custom tableview cell)

This code does work, and does reuse cells properly.

H Asseily,

Perhaps you are working with SDK 2.1? In 2.0 I have no problems with reuse of table cells created in code. Table cells loaded from nib files however are not being reused. I have tried setting the file's owner to NSObject and UIViewController (using loadNibNamed and initWithNibName respectively). The identifier is set in the nib and is the same value passed to dequeueReusableCellWithIdentifier. I have not run this on the phone but in the simulator it's not reusing the cell.

I stand corrected - it is reusing my cells.

I hope I don't break the NDA by this, but I think a word of warning is due here: Please don't use the array returned by -loadNibNamed:owner:options: for anything but retaining it. Objects in the nib should only be accessed through the owner's outlets. You never know in which order the Nib's root objects are in the array.

Things like this are BAD practice and a very good example why Apple should lift the NDA so we can legally talk about this.