Swift: How do I handle a double with two decimal places in a tableView?

Question

I've been trying to work this out for some little while now.

I've got a double in my array, but it invariably displays as a rounded integer.

var dataArray: [(colorNo: String, colour: NSColor, spares: Double)] = []

Here's the tableView:

    func numberOfRowsInTableView(aTableView: NSTableView) -> Int {
        return dataArray.count
    }
}

extension ViewController: NSTableViewDelegate {
    func tableView(tableView: NSTableView,
                   viewForTableColumn tableColumn: NSTableColumn?,
                   row: Int) -> NSView? {
        if let column = tableColumn {
            if let cellView = tableView.makeViewWithIdentifier(column.identifier, owner: self) as? NSTableCellView {
                let thread = dataArray[row]
                if column.identifier == "colourNo" {
                    cellView.textField?.stringValue = "\(thread.colourNo)"
                    return cellView
                }
                if column.identifier == "colour" {
                    cellView.textField?.backgroundColor = thread.colour
                    return cellView
                }
                if column.identifier == "spares" {
                    let val = Double(thread.spare)
                    cellView.textField?.doubleValue = val
                    return cellView
                }
                return cellView
            }
        }
        return nil
    }
}

and here's the definition of the field in Xcode:

Whenever I enter a decimal value...

It invariably reverts to integer:

I'm sure it must be blindingly obvious to someone out there, but I'm afraid it isn't to me.

Any ideas?

Where does the `thread.spare` in `let val = Double(thread.spare)` come from? — Alexander, Jun 15 '20 at 14:37
You have `spare` in table view code but `spares` in the tuple, I assume it is a typo? Why do you create a new Double from a Double in the cell? How is the number formatter set up? — Joakim Danielson, Jun 15 '20 at 15:05
"spares" is the column identifier, not the field in the tuple. The number formatter is style: Decimal, Minimum: 0, Maximum: 99.99, Localize Format and Lenient both checked. As mentioned below, In the code, I've also tried .usesGroupingSeparator, .minimumFractionDigits = 0, .maximumFractionDigits = 2, .locale = NSLocale.currentLocale(), yet none of this appears to make any difference to the output. — pastewort, Jun 15 '20 at 19:52

score 0 · Accepted Answer · answered Jun 15 '20 at 15:06

0

This has nothing to do with any of the code you've shown. — You've got a NumberFormatter on your cell. The way a string entered into the field is interpreted as a Double, and the way the Double value is displayed as a string in the interface, depends upon the configuration of that formatter. Configure it to display stuff after the decimal point and that's what it will do.

answered Jun 15 '20 at 15:06

matt

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875
1,141

I tried that, but however I configure it, seemingly, it still shows integers. In the Number Formatter in Attributes Inspector, I set the style to Decimal, and it still shows an integer whatever is entered as Sample Input. I've also tried .usesGroupingSeparator, .minimumFractionDigits = 0, .maximumFractionDigits = 2, .locale = NSLocale.currentLocale() and none of this appears to make any difference to the output. – pastewort Jun 15 '20 at 18:44
Finally got it - thanks matt. Changed the Number Formatter Behaviour in Attributes Inspector from Default to Custom, and loads of additional configuration options opened up! – pastewort Jun 16 '20 at 10:26

Swift: How do I handle a double with two decimal places in a tableView?

1 Answers1