Introduction

ViewportMixin is a mixin that provides event handlers for elements on the page that can be scrolled into and out of view.

About Mixins

Mixins provide functionality that other elements can inherit and use.

Mixins are not elements. You cannot add mixins to a page in the Editor like other $w elements, and mixins are not meant to be used directly in your code.

For example, you would not write code like this, because it is out of context:

$w("#ViewportMixin").onViewportEnter( (event) => {
   let targetId = event.target.id; 
});

Instead, you can code the following if myElement is an element that "mixes in" ViewportMixin.

$w("#myElement").onViewportEnter( (event) => {
   let targetId = event.target.id; 
});