Generic function to get any class of NSView for a NSTableView

getRowViewGeneric.swift

import Cocoa

// Use this as a helper function in your table view delegate.

func getRowView<T: NSView>(_ tableView: NSTableView) -> T {
    let identifier = NSUserInterfaceItemIdentifier(
        rawValue: "\(T.self)")

    var dequeuedRowView: T? = tableView.makeView(
        withIdentifier: identifier, owner: self
        ) as? T

    if dequeuedRowView == nil {
        dequeuedRowView = T.fromNib()
        dequeuedRowView?.identifier = identifier
    }

    guard let rowView: T = dequeuedRowView
        else { fatalError("Unable to get a \(T.self)") }

    return rowView
}