scrolldir-observable
Get the direction of scrolling - as an observable
Install
Usage
via import
// will react on scroll events that happen on the document
const scrollDir$ = scrollDirObservable(window.document);
scrollDir$.subscribe(dir => {
console.log(dir); // 'up' or 'down', depending on the scroll direction
});
The observable only emits values on the first scroll or when the scroll direction changes. So if the user e.g. scrolls down for 2 seconds, the observable will emit the value down only once.
via script tags
In case you want to use this library via script tags, you can do it like this
<html>
<head>
<script type="module" src="scrolldir-observable/dist/bundles/scrolldir-observable.es.min.js">script>
<script nomodule src="scrolldir-observable/dist/bundles/scrolldir-observable.umd.min.js">script>
head>
...
html>
It tries to load the library as an ES module and if that is not supported, it will fall back to an UMD module. Further details can be found in Jake Archibald's great article ECMAScript modules in browsers.
API
scrollDirObservable(element: HTMLElement | Document, windowElem: Window = window): Observable
element: Some html element or the document on which scroll directions should be observed.
windowElem: The global window object - defaults to window - if you use this library directly in the browser, you need not to care about this parameter.
Directions: 'up' | 'down'
String, which describes the direction of the scroll.
Development
npm run build: compiles library into the dist folder:- standalone (used, if consumers want to bundle it themselves):
dist/index.jsdist/index.es.js
- bundles (direct usage via script tags (see Usage)):
dist/bundles/scrolldir-observable.es.min.jsdist/bundles/scrolldir-observable.umd.min.js
- types:
dist/types/index.d.ts
- standalone (used, if consumers want to bundle it themselves):
npm test: executes all tests
License
MIT