How to use Webapi.Performance.now()

[t-gebauer]

Webapi.Performance is defined as:

type t

@send external now: t => float = "now"

now() requires an argument of type t, but I could not find a way to get a value of type t with this library.

I ended up writing my own external for it.

  @val external performance: Webapi.Performance.t = "performance"

Shouldn't this be equivalent to how document and window are handled?

@val external window: Dom.window = "window"
@val external document: Dom.document = "document"

[spocke]

It's defined here it takes a window instance and returns a performance t instance.

https://github.com/tinymce/rescript-webapi/blob/main/src/Webapi/Dom/Webapi__Dom__Window.res#L54

So window->Window.performance->Performance.now should work.

[TheSpyder]

The thing to remember is we don't use implicit globals. The only exception we make is document, because it's so common, everything else must come via window.
https://github.com/tinymce/rescript-webapi/blob/9f616918907ea67b29a4174fd851be0caea8e617/src/Webapi/Webapi__Dom.res#L86-L89

This is done both to better match the spec and also handle situations where a reference from a different window (such as an iframe) needs to be used.