Expand tableview and increase scrollview content size by an appropriate difference on clicking a button inside a table cell

Question

I have a UITableView which has been added inside a UIScrollView as part of a view controller which adheres to a part of the mockup shown below:-

As you can see

Answer 1

Try this

func expandCell(_ sender: UI.Button) {
    if self.parent!.indexOfCellToExpand != self.tag {
        print("EXPANDING...")
        self.parent!.indexOfCellToExpand = self.tag
        self.parent!.businessTable.reloadRows(at: [IndexPath(row: self.tag, section: 0)], with: .fade)
        self.parent!.businessTable.scrollToRow(at: IndexPath(row: self.tag, section: 0), at: .top, animated: true)
    }
    else if self.parent!.indexOfCellToExpand == self.tag {
        print("CONTRACTING...")
        self.parent!.indexOfCellToExpand = -1
        self.parent!.businessTable.reloadRows(at: [IndexPath(row: self.tag, section: 0)], with: .fade)
        self.parent!.businessTable.scrollToRow(at: IndexPath(row: self.tag, section: 0), at: .top, animated: true)
    }
    //        self.toggleBusinessesTable()
    yourTableView.reloadData()
}

Answer 2

Instead of calculating heights and modifying the scroll view's .contentSize, you can use auto-layout with a subclassed UITableView that determines its own height:

final class ContentSizedTableView: UITableView {

    override var contentSize:CGSize {
        didSet {
            invalidateIntrinsicContentSize()
        }
    }

    override var intrinsicContentSize: CGSize {
        layoutIfNeeded()
        return CGSize(width: UIView.noIntrinsicMetric, height: contentSize.height)
    }

}

When you change the table view - either adding / removing rows or sections, or changing the row heights - the table view's intrinsicContentSize will be automatically updated, and its height will grow or shrink just like a multi-line UILabel.

With the constraints setup properly, auto-layout will handle the scroll view's content size for you.