OptionController value coercing number to string

Inside OptionController by using the HTML DOM option object and specifically the inherited setAttribute method any value in a list of possible options that should be a number will subsequently be converted into a string by the native implementation of setAttribute method.

https://github.com/dataarts/dat.gui/blob/8cd1b4d2ae0982b63105deedac320004373af99b/src/dat/controllers/OptionController.js#L54

Happens when wanting to have multiple numbers as options when using add with args that are of type: add(target: Object, propName:string, items:number[]): GUIController;

https://developer.mozilla.org/en-US/docs/Web/API/Element/setAttribute

[MacroMan]

The values of a select input will always be of type string. That’s the HTML spec, and so cannot remain a number.

You could subscribe to the onchange event and coerce them back using Number or parseInt.

[neillrobson]

I was also stumped for a little while on how to elegantly solve this issue. The following function worked for me:

function toNumber(value) {
    this.object[this.property] = Number(value);
}

gui.add(obj, "name", { Zero: 0, One: 1 }).onChange(toNumber);

I do think that it would be good to mention this constraint (and perhaps provide alternative solutions such as the above function) somewhere in the documentation.