Swift NSTableview convert obj-c to swift - macos

Question

Hey the original apple guide in obj-c is here,
https://developer.apple.com/library/mac/documentation/Cocoa/Conceptual/TableView/PopulatingView-TablesProgrammatically/PopulatingView-TablesProgrammatically.html#//apple_ref/doc/uid/10000026i-CH14-SW6
example 3.2
I have been following through the guide and can not get the program to work, i am getting these errors:
'AnyObject?' does not have a member named 'identifier'
line: result.identifier = "HelloWorld"
and
error: cannot convert the expression's type 'AnyObject?' to type '()'
Line: return result
What am i doing wrong?
func tableView(tableView: NSTableView, viewForTableColumn tableColumn: NSTableColumn, row: Int){
var names: [String] = ["Anna","Alex","brain","jack","gg"]
var result: AnyObject? = tableView.makeViewWithIdentifier("HelloWorld", owner: self)
if result == nil
{
// Create the new NSTextField with a frame of the {0,0} with the width
// of the table.
result = NSTextField(frame: NSRect())
// set identifier of the NSTextField instance to HelloWorld.
result.identifier = "HelloWorld"
}
result = names[row]
return result
}
New Working code
func tableView(tableView: NSTableView, viewForTableColumn tableColumn: NSTableColumn, row: Int) -> NSTextField{
var names = ["Anna","Alex","Brain","Jack","Hello"]
var result: NSTextField? = tableView.makeViewWithIdentifier("HelloWorld", owner: self) as? NSTextField
if result == nil
{
// Create the new NSTextField with a frame of the {0,0} with the width
// of the table.
result = NSTextField(frame: NSRect())
// set identifier of the NSTextField instance to HelloWorld.
result?.identifier = "HelloWorld"
}
result!.bezeled = false
result?.stringValue = names[row]
return result!
}

Answer 1

Here:
var result: AnyObject? = tableView.makeViewWithIdentifier("HelloWorld", owner: self)
you have declared the result variable as an optional AnyObject - and this protocol doesn't have an identifier property, which is instead a property of NSTextField.
What you should do is declare that variable using the correct type:
var result: NSTextField? = tableView.makeViewWithIdentifier("HelloWorld", owner: self) as? NSTextField
which can also be shortened thanks to type inference:
var result = tableView.makeViewWithIdentifier("HelloWorld", owner: self) as? NSTextField
Side note: I think your if is checking for the opposite condition:
if result != nil
whereas I think it should be:
if result == nil
Side note 2
There's no return value declared in your function, but you are returning an instance of NSTextField.
You should change the signature to:
func tableView(tableView: NSTableView, viewForTableColumn tableColumn: NSTableColumn, row: Int) -> NSView
and change the return statement to:
return result!
Note that result is defined as optional, but looking at the method implementation, at the end a non-nil value is available, so I've used forced unwrapping and declared the method to return a non-optional value. Of course feel free to change that if you want.