How to get multiple copies of a UIView loaded from a nib?

Question

I want to use a UIView hierarchy multiple times (the nib object is a template). Unfortunately, UIView does not conform to <NSCopying> so

[cell.contentView addSubview: [[templEditCellView copy] autorelease]];

does not work.

I wasn't surprised, since I want a deep copy of the view hierarchy.

Currently the view is one of several top-level objects in the nib it is loaded from. Is there a way to reload a single specified top-level object from the nib? Should I split out the view to a single NIB which can be reloaded on demand? Or is there another way to make a deep copy of a view?

Thanks!

score 7 · Answer 1 · answered May 08 '10 at 00:57

7

Easiest way to make a deep copy of a view is to archive and unarchive it.

id copyOfAView = 
  [NSUnarchiver unarchiveObjectWithData:
    [NSArchiver archivedDataWithRootObject:aView]];

Putting the view in its own nib works too. You can create an NSNib object and reload it as many times as you want.

answered May 08 '10 at 00:57

NSResponder

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So I could load my template object graphs (UIViews) once from a nib, archive them to data in a dictionary, and unarchive them individually on demand. I might need to know the performance tradeoff between your simple copy equivalent and my idea of caching the archived data in memory? – dmaestro12 May 10 '10 at 18:24
If you have the views in question in their own nib files, then my suggestion above is redundant. You can load the nib as many times as you want. – NSResponder May 12 '10 at 09:54
UINib *)nibWithNibName will allow you to load a nib as an archive skipping the archive step. – zaph Jul 23 '11 at 13:29
Note that this doesn't replicate interface builder actions that were bound to controls within aView. – Ben Gotow Apr 11 '12 at 21:17

score 2 · Accepted Answer · answered May 07 '10 at 15:55

2

You can't load it directly to the cell's content view, but you can create a class with outlets for the view(s) and load it with

[[NSBundle mainBundle] loadNibNamed:@"TheNib" owner:anObject options:nil];

There is more info around SO and the 'net about loading table view cells from nibs. I really like Bill Dudney's approach but the method described by Jeff LaMarche is easier and great for many situations.

answered May 07 '10 at 15:55

Felixyz

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I see an echo between Bill's approach and the one I'm trying. I see that the separate-nib approach is quite workable, just wonder if there are any better. I am severely customizing my UITableCell views! Thanks for the good pointers. – dmaestro12 May 07 '10 at 16:15

score 1 · Answer 3 · answered May 07 '10 at 16:22

This seems to be working well at the moment for what I need:

if (! templEditCellView) {
  [[NSBundle mainBundle] loadNibNamed:@"TextEditCellView" owner:self options:nil];
  if (! templEditCellView) {
    abort(); // !!
  }
}
[cell.contentView addSubview: templEditCellView];
templEditCellView = nil;

The table controller is placing the same customized view heirarchy in the content of each cell in this case.

I'd love to see an approach that doesn't multiply nib files if I have lots of different cell customizations (as I might).

How to get multiple copies of a UIView loaded from a nib?

3 Answers3