How to get Storyboard to support dynamically sized cells in UICollectionView?

ios, storyboard, uicollectionview, uicollectionviewcell, xcode

Solution

The simplest way seems to be over-riding the cell size via the delegate within my main View Controller:

- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath {
    float cellWidth = (self.view.frame.size.width / 2) - 35;
    float cellHeight = cellWidth * 190.0f / 270.0f;
    return CGSizeMake(cellWidth, cellHeight);
}

I'd prefer to have as much display logic in the storyboard, but I suppose this is room for future improvement for Apple.

Problem

I have the following layout in my dynamically-sized Storyboard: However, when running the application (depending on the orientation), cells look like the following: This is to be expected, because the previous cells had static heights and widths. However, I'd like the cells to resize dynamically based on the device width (height can remain static for this purpose). The CollectionView itself resizes properly, because it's pinned to its superview, so how can cells be overridden with auto-layout constraints (vs. the static cell sizes dictated from the UICollectionView).

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