Detaching functions in javascript while retaining their context?

Question

Is it possible to detach functions in javascript while allowing them to retain access to their context?

For example suppose we have a ViewportScroller instance called vc. We can get the current scroll position by calling:

vc.getScrollPosition()

Is it possible to detach it like this:

cont scrollPosition = vc.getScrollPosition

While ensuring that it will still work and be able to access everything it needs to work or do we always need to wrap vc like this:

const scrollPostion = ()=>vc.getScrollPosition()

`let scrollPostion = vc.getScrollPosition.bind(vc)`. See [*How does the “this” keyword work?*](https://stackoverflow.com/questions/3127429/how-does-the-this-keyword-work) and [*What is the use of the JavaScript 'bind' method?*](https://stackoverflow.com/questions/2236747/what-is-the-use-of-the-javascript-bind-method) — RobG, Dec 14 '19 at 21:12
Does this answer your question? [What is the use of the JavaScript 'bind' method?](https://stackoverflow.com/questions/2236747/what-is-the-use-of-the-javascript-bind-method) — Dexygen, Dec 14 '19 at 21:23

score 2 · Accepted Answer · answered Dec 14 '19 at 21:12

You can also use .bind

The bind() method creates a new function that, when called, has its this keyword set to the provided value, with a given sequence of arguments preceding any provided when the new function is called.

cont scrollPosition = vc.getScrollPosition.bind(vc)

Detaching functions in javascript while retaining their context?

1 Answers1