I haven't seen a thread that handles this, at least not for React.
My case: I want to conditionally render a back to top button only when scrolling is an option. It makes no sense to have such a feature if it can't affect the page.
The only solutions I can find are in jQuery. I'm using react-scroll but couldn't find any functionality there for this.
Luke.
By "scrolling is an option" I am assuming here that you mean "when the scrollbar is visible."
As far as I am aware, there is not any way to check for scrollbar visibility using the React API. There is the DOM boolean window.scrollbars.visible; however, I have not had luck with this. It seems to always return true whether a scrollbar is visible or not. The following approach may work for you:
You could set an event listener for onScroll and check window.scrollY. If window.scrollY > 0, then you could conditionally render the button. If window.scrollY is 0, then the page is already scrolled to the top and there is no need to display the button.
Depending on the design of your web app, checking once for scrollbar visibility (e.g., on componentDidMount) may not be the best option, since some DOM elements may continue to load after the component initially mounts and the height of the page may change.
I hope this is helpful.