Web component

Page file

page.js

Web component is imported in this file

import { Component, html } from '@thewebformula/lithe';
/* HTML imports will bundle with the build */
import htmlTemplate from './page.html';

// imported component
import './component.js';

export default class extends Component {
  // html page title
  static title = 'Page';

  // you can set the html from and import or use the template method (see below)
  static htmlTemplate = htmlTemplate;
  
  constructor() {
    super();
  }

  // this can be used in place of import the html file
  template() {
    return html`
      <div>Page Content</div>

      <!-- custom component -->
      <custom-button>Click</custom-button>
    `;
  }
}

Component file

component.js

<!-- component.html -->
<button><slot></slot></button>

import { Component } from '@thewebformula/lithe';
import htmlTemplate from './component.html';

class CustomButton extends Component {
  /**
    * Pass in HTML string. Use for imported .HTML
    * Supports template literals: <div>undefined</div>
    * @type {String}
    */
  static htmlTemplate = htmlTemplate;


  /**
    * Hook up shadow root
    * @type {Boolean}
    */
  static useShadowRoot = false;

  
  /**
    * @type {Boolean}
    */
  static shadowRootDelegateFocus = false;


  /**
    * Pass in styles for shadow root.
    * Can use imported stylesheets: import styles from '../styles.css' assert { type: 'css' };
    * @type {CSSStyleSheet}
    */
  static shadowRootStyleSheets;


  /**
    * @typedef {String} AttributeType
    * @value '' default handling
    * @value 'string' Convert to a string. null = ''
    * @value 'number' Convert to a number. isNaN = ''
    * @value 'int' Convert to a int. isNaN = ''
    * @value 'boolean' Convert to a boolean. null = false
    * @value 'event' Allows code to be executed. Similar to onchange="console.log('test')"
    */
    /**
    * Enhances observedAttributes, allowing you to specify types
    * You can still use `observedAttributes` in stead of this.
    * @type {Array.<[name:String, AttributeType]>}
    */
  static get observedAttributesExtended() { return []; }; // static observedAttributesExtended = [['required', 'boolean']];
  

  /**
    * Use with observedAttributesExtended
    * You can still use `attributeChangedCallback` in stead of this.
    * @function
    * @param {String} name - Attribute name
    * @param {String} oldValue - Old attribute value
    * @param {String} newValue - New attribute value
    */
  attributeChangedCallbackExtended(name, oldValue, newValue) { }


  // need to bind events to access `this`
  #onClick_bound = this.#onClick.bind(this);

  
  constructor() {
    super();
  }

  /**
    * Method that returns a html template string. This is an alternative to use static htmlTemplate
    * @name template
    * @function
    * @return {String}
    */
  template() { return '<div></div>' }

  connectedCallback() {}
  disconnectedCallback() {}
  beforeRender() {}

  afterRender() {
    this.#root.querySelector('button').addEventListener('click', this.#onClick_bound);
  }
  
  disconnectedCallback() {
    this.#root.querySelector('button').removeEventListener('click', this.#onClick_bound);
  }

  #onClick() {
    console.log('Custom button component clicked!');
  }
}

// define web component
customElements.define('custom-button', CustomButton);

Interacting with component elements

<!-- index.html -->
<body>
  <custom-webcomponent></custom-webcomponent>
</body>

<!-- component.html -->
<button onclick="this.closest('custom-webcomponent').clickIt()">Click it direct</button>
<button id="eventlistener-button">Click it event listener</button>

import { Component } from '@thewebformula/lithe';
import html from './component.html'; // automatically bundles

class CustomWebcomponent extends Component {
  static htmlTemplate = html;

  // need to bind events to access `this`
  #onClick_bound = this.clickIt.bind(this);

  varOne = 'var one';

  
  constructor() {
    super();
  }

  afterRender() {
    this.#root.querySelector('#eventlistener-button').addEventListener('click', this.#onClick_bound);
  }
  
  disconnectedCallback() {
    this.#root.querySelector('#eventlistener-button').removeEventListener('click', this.#onClick_bound);
  }

  clickIt() {
    console.log('click it!');
  }
}

// define web component
customElements.define('custom-webcomponent', CustomWebcomponent);