[Interest] undefined as JS object key in QML?

[Jérôme Godbout]

The key is always a string into named array, so you undefined key is transform (optional quote there for JS which is lazy and useless rule) into "undefined" string literal.

What you want to do is a prototype or a function that will verify this for you:

function dictKey(dict, key, defaultKey = "undefined")
{
  if(key === undefined || !(key in dict))
     return dict[defaultKey];
  return dict[key];	
}

That would do it in a better way, you can also make it a prototype if you want, make it easier to use most of the time.
dictKey(textForColor, color) should now return the proper value and the binding should still work.

-----Original Message-----
From: Interest <interest-bounces at qt-project.org> On Behalf Of Jason H
Sent: January 3, 2020 11:46 AM
To: interestqt-project.org <interest at qt-project.org>
Subject: [Interest] undefined as JS object key in QML?

Simplified example:
Text {
    property var textForColor: {"transparent": "Waiting", "lime": "Ready", undefined: "Initializing"}
    text: textForColor[color]
    color: // set somewhere else, potentially undefined at the start }

But if I include the undefined key, QML complains.
Fails execution with: Expected token `}'
If the undefined key-pair is first, then QtCreator complains that the colon after "transparent" as:
  Expected token `,'
If the undefined key-pair is last, then QtCreator complains that the colon after "transparent" as:
  Invalid property name "text"


However in Node it works just fine (JS REPL):
> var a = {undefined: "!", "1":"B"};
undefined
> a
{ '1': 'B', undefined: '!' }
> a[undefined]
'!'
> Object.keys(a)
[ '1', 'undefined' ]

Bug?
Sure there are ways to work around this (change undefined to be a string, and when indexing color, make that a string too) but shouldn't this be able to support it as undefined itself?
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