custom-elements

components.text-markup\.js

import Component from '@glimmer/component';

export default class extends Component {
}

class EncodedText extends HTMLElement {
  _state = 'encoded';
  get isEncoded() {
    return  this._state === 'encoded';
  }
  set isEncoded(value) {
    this._state = value ? 'encoded' : 'decoded';
    this.render();
  }
  connectedCallback() {
    this.setAttribute('role', 'button');
    this.addEventListener('click', () => {
      this.isEncoded = !this.isEncoded;
    });
    this.updateValue();
  }
  attributeChangedCallback() {
    this.updateValue();
  }
  render() {
    this.dataset.state = this._state;
    this.textContent = this.isEncoded ? this.value : atob(this.value);
  }
  updateValue() {
    this.value = this.getAttribute('value');
    this.render();
  }
  static get observedAttributes() {
    return ['value'];
  }
}

customElements.define('encoded-text', EncodedText);

controllers.application\.js

import Controller from '@ember/controller';

export default class ApplicationController extends Controller {
  appName = 'Ember Twiddle';
}

templates.application\.hbs

<TextMarkup @text="Zm9vYmFy" />

templates.components.text-markup\.hbs

<encoded-text value={{@text}}></encoded-text>

twiddle\.json

{
  "version": "0.17.1",
  "EmberENV": {
    "FEATURES": {},
    "_TEMPLATE_ONLY_GLIMMER_COMPONENTS": false,
    "_APPLICATION_TEMPLATE_WRAPPER": true,
    "_JQUERY_INTEGRATION": true
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/3.5.1/jquery.js",
    "ember": "3.18.1",
    "ember-template-compiler": "3.18.1",
    "ember-testing": "3.18.1"
  },
  "addons": {
    "@glimmer/component": "1.0.0"
  }
}