ember in-view example

components.page-section.js

import Ember from 'ember';
import InViewportMixin from 'ember-in-viewport';

export default Ember.Component.extend(InViewportMixin, {
  tagName: 'section',
  classNames: ['page-section'],
  classNameBindings: [ 'viewportEntered:active' ],
});

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName: 'ember-in-view example'
});

styles.app.css

body {
  margin: 12px 16px;
  font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif;
  font-size: 12pt;
}

.page-section {
  border: 1px solid red;
  min-height: 120vh;
  transition: background-color 1s;
}

.page-section.active {
  background-color: lightblue;
}

templates.application.hbs

<h1>{{appName}}</h1>


<PageSection />

<PageSection />

<PageSection />

templates.components.page-section.hbs

{{yield}}

twiddle.json

{
  "version": "0.15.1",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.js",
    "ember": "3.4.3",
    "ember-template-compiler": "3.4.3",
    "ember-testing": "3.4.3"
  },
  "addons": {
    "ember-data": "3.4.2",
    "ember-in-viewport": "3.2.2"
  }
}