WebComponents in 2023: A Complete Exploration Horacio Gonzalez 2023-10-02 #Devoxx #WebComponents

Who are we? Introducing myself and introducing OVHcloud #Devoxx #WebComponents

Horacio Gonzalez @LostInBrittany Spaniard Lost in Brittany #Devoxx #WebComponents

OVHcloud Web Cloud & Telcom 30 Data Centers in 12 locations 1 Million+ Servers produced since 1999 Private Cloud 34 Points of Presence on a 20 TBPS Bandwidth Network 1.5 Million Customers across 132 countries Public Cloud 2200 Employees worldwide 3.8 Million Websites hosting Storage 115K Private Cloud VMS running 1.5 Billion Euros Invested since 2016 300K Public Cloud instances running P.U.E. 1.09 Energy efficiency indicator 380K Physical Servers running in our data centers 20+ Years in Business Disrupting since 1999 Network & Security #Devoxx #WebComponents

We want the code! https://github.com/LostInBrittany/web-components-in-2023/ #Devoxx #WebComponents

What the heck are web component? The 3 minutes context #Devoxx #WebComponents

Web Components Web standard W3C #Devoxx #WebComponents

Web Components Available in all modern browsers: Firefox, Safari, Chrome #Devoxx #WebComponents

Web Components Create your own HTML tags Encapsulating look and behavior #Devoxx #WebComponents

Web Components Fully interoperable With other web components, with any framework #Devoxx #WebComponents

Web Components CUSTOM ELEMENTS SHADOW DOM #Devoxx #WebComponents TEMPLATES

Custom Element To define your own HTML tag <body> … <script> window.customElements.define(‘my-element’, class extends HTMLElement {…}); </script> <my-element></my-element> </body> #Devoxx #WebComponents

Shadow DOM To encapsulate subtree and style in an element <button>Hello, world!</button> <script> var host = document.querySelector(‘button’); const shadowRoot = host.attachShadow({mode:’open’}); shadowRoot.textContent = ‘こんにちは、影の世界!’; </script> #Devoxx #WebComponents

Template To have clonable document template <template id=”mytemplate”> <img src=”” alt=”great image”> <div class=”comment”></div> </template> var t = document.querySelector(‘#mytemplate’); // Populate the src at runtime. t.content.querySelector(‘img’).src = ‘logo.png’; var clone = document.importNode(t.content, true); document.body.appendChild(clone); #Devoxx #WebComponents

But in fact, itʼs just an element… ● ● ● ● Attributes Properties Methods Events #Devoxx #WebComponents

Sometimes I feel a bit grumpy The stories of the grumpy old speaker… #Devoxx #WebComponents

On Polymer tour since 2014 #Devoxx #WebComponents

Image: bu.edu Web components == Revolution #Devoxx #WebComponents

Images: BitRebels & Brickset Building a world brick by brick #Devoxx #WebComponents

Is the promise unfulfilled? It’s 2023 now, where is your revolution, dude? #Devoxx #WebComponents

Is it a conspiracy? #Devoxx #WebComponents

Am I only a dreamer? #Devoxx #WebComponents

Well, revolution IS there But it’s a silent one… #Devoxx #WebComponents

I as looking for a great example #Devoxx #WebComponents

New Reddit runs on Web Components #Devoxx #WebComponents

Often hidden in plain sight #Devoxx #WebComponents

Vanilla Web Components #Devoxx #WebComponents

Let’s build a vanilla Web Component Using only HTML, CSS & JS, no library needed #Devoxx #WebComponents

A very basic web component class HelloWorld extends HTMLElement { // This gets called when the HTML parser sees your tag constructor() { super(); // always call super() first in the ctor. this.msg = ‘Hello World!’; } // Called when your element is inserted in the DOM or // immediately after the constructor if it’s already in the DOM connectedCallback() { this.innerHTML = <p>${this.msg}</p>; } } customElements.define(‘hello-world’, HelloWorld); #Devoxx #WebComponents

Custom Elements: ● Let you define your own HTML tag with bundled JS behavior ● Trigger lifecycle callbacks ● Automatically “upgrade” your tag when inserted in the document #Devoxx #WebComponents

Custom Elements donʼt: ● Scope CSS styles ○ Shadow DOM ● Scope JavaScript ○ ES2015 ● “Reproject” children into <slot> elements ○ Shadow DOM #Devoxx #WebComponents

Adding ShadowDOM class HelloWithShadowdom extends HTMLElement { // This gets called when the HTML parser sees your tag constructor() { super(); // always call super() first in the ctor. this.msg = ‘Hello World from inside the ShadowDOM!’; this.attachShadow({ mode: ‘open’ }); } // Called when your element is inserted in the DOM or // immediately after the constructor if it’s already in the DOM connectedCallback() { this.shadowRoot.innerHTML = <p>${this.msg}</p>; } } customElements.define(‘hello-with-shadowdom’, HelloWithShadowdom); #Devoxx #WebComponents

Using web components <!DOCTYPE html> <html> <head> <title>Vanilla Web Components</title> <script src=”./hello-world.js”></script> <script src=”./hello-with-shadowdom.js”></script> </head> <body> <hello-world></hello-world> <hello-with-shadowdom></hello-with-shadowdom> </body> </html> #Devoxx #WebComponents

Using web components #Devoxx #WebComponents

Lifecycle callbacks class MyElementLifecycle extends HTMLElement { constructor() { // Called when an instance of the element is created or upgraded super(); // always call super() first in the ctor. } static get observedAttributes() { // Tells the element which attributes to observer for changes return []; } connectedCallback() { // Called every time the element is inserted into the DOM } disconnectedCallback() { // Called every time the element is removed from the DOM. } attributeChangedCallback(attrName, oldVal, newVal) { // Called when an attribute was added, removed, or updated } adoptedCallback() { // Called if the element has been moved into a new document } } #Devoxx #WebComponents

my-vanilla-counter element class MyVanillaCounter extends HTMLElement { constructor() { super(); this._counter = 0; this.attachShadow({ mode: ‘open’ }); } connectedCallback() { this.render(); this.display(); } static get observedAttributes() { return [ ‘counter’ ] } // We reflect attribute changes into property changes attributeChangedCallback(attr, oldVal, newVal) { if (oldVal !== newVal) { this[attr] = newVal; } } #Devoxx #WebComponents

my-counter custom element // Getter and setters for counter get counter() { return this._counter; } set counter(value) { if (value != this._counter) { this._counter = Number.parseInt(value); this.setAttribute(‘counter’, value); this.display(); } } increment() { this.counter = this.counter + 1; this.dispatchEvent(new CustomEvent(‘increased’, {detail: {counter: this.counter}})); } #Devoxx #WebComponents

my-counter custom element render() { let container = document.createElement(‘div’); container.style.display = ‘flex’; … this.style.fontSize = ‘5rem’; } display() { this.output.innerHTML = ${this.counter}; } } customElements.define(my-vanilla-counter, MyVanillaCounter); #Devoxx #WebComponents

my-counter-with-templates let template = ` <style> … </style> <div class=”container”> <div id=”icon”> <img src=”${import.meta.url}/../img/logo.png”>

</div> <div id=”value”> 0 </div> </div> `; #Devoxx #WebComponents

my-counter-with-templates render() { let templ = document.createElement(‘template’); templ.innerHTML = template; this.shadowRoot.appendChild(templ.content.cloneNode(true)); let button = this.shadowRoot.getElementById(‘icon’); button.addEventListener(‘click’, this.increment.bind(this)); } display() { console.log(this.shadowRoot.getElementById(‘value’)) this.shadowRoot.getElementById(‘value’).innerHTML = ${this.counter}; } #Devoxx #WebComponents

Coding my-counter #Devoxx #WebComponents

my-counter custom element #Devoxx #WebComponents

Why those libs? Why people don’t use vanilla? #Devoxx #WebComponents

Web component standard is low level At it should be! #Devoxx #WebComponents

Standard == basic bricks Standard exposes an API to: ○ Define elements ○ Encapsulate DOM #Devoxx #WebComponents

Libraries are helpers They give you higher-level primitives #Devoxx #WebComponents

Different high-level primitives Each one tailored to a use #Devoxx #WebComponents

Sharing the same base High-performant, low-level, in-the-platform web components standard #Devoxx #WebComponents

Libraries aren’t a failure of standard They happen by design #Devoxx #WebComponents

A library for building reusable, scalable component libraries #Devoxx #WebComponents

Not another library A Web Component toolchain #Devoxx #WebComponents

A build time tool To generate standard web components #Devoxx #WebComponents

Fully featured ● Web Component-based ● Component pre-rendering ● Asynchronous rendering pipeline ● Simple component lazy-loading ● TypeScript support ● JSX support ● Reactive Data Binding ● Dependency-free components #Devoxx #WebComponents

And the cherry on the cake Server-Side Rendering #Devoxx #WebComponents

Stencil leverages the web platform #Devoxx #WebComponents

The Stencil story A company tired of putting good code in the bin #Devoxx #WebComponents

Once upon a time there was a fight Between native apps and web app on mobile #Devoxx #WebComponents

A quest to the perfect solution Hybrid apps, leveraging on web technologies #Devoxx #WebComponents

A company wanted to do it well The perfect technology for mobile web and hybrid apps #Devoxx #WebComponents

The time is 2013 So what technology would you use? #Devoxx #WebComponents

Really soon after launch… Hey folks, we are killing AngularJS! #Devoxx #WebComponents

What did Ionic people do? Let’s put everything in the trash bin and begin anew #Devoxx #WebComponents

But times have changed… In 2013 Angular JS was the prom queen #Devoxx #WebComponents

Times have changed… In 2017 Angular is only one more in the clique #Devoxx #WebComponents

Angular limits adoption of Ionic Devs and companies are very vocal about JS Frameworks #Devoxx #WebComponents

What did Ionic people do? Let’s put everything in the trash bin and begin anew… But on which framework? #Devoxx #WebComponents

What about web components? A nice solution for Ionic problems: Any framework, even no framework at all! #Devoxx #WebComponents

But what Web Component library? SkateJS There were so many of them! #Devoxx #WebComponents

Let’s do something different A fully featured web component toolchain With all the bells and whistles! #Devoxx #WebComponents

Ionic rewrote all their code again From Ionic 4 is fully based on Stencil #Devoxx #WebComponents

Now Ionic works on any framework Or without framework at all #Devoxx #WebComponents

And we have Stencil To use it in any of our projects #Devoxx #WebComponents

Hands on Stencil Simply use npm init npm init stencil Choose the type of project to start ? Select a starter project. Starters marked as [community] are developed by the Stencil Community, rather than Ionic. For more information on the Stencil Community, please see https://github.com/stencil-community › - Use arrow-keys. Return to submit. ❯ component Collection of web components that can be used anywhere app [community] Minimal starter for building a Stencil app or website ionic-pwa [community] Ionic PWA starter with tabs layout and routes #Devoxx #WebComponents

Hands on Stencil And the project is initialized in some seconds! ✔ Pick a starter › component ✔ Project name › my-stencil-counter ✔ All setup in 17 ms $ npm start Starts the development server. $ npm run build Builds your components/app in production mode. $ npm test Starts the test runner. We $ $ $ suggest that you begin by typing: cd my-stencil-counter npm install npm start Happy coding! 🎈 #Devoxx #WebComponents

Let’s look at the code #Devoxx #WebComponents

Some concepts import { Component, Prop, h } from ‘@stencil/core’; import { format } from ‘../../utils/utils’; @Component({ tag: ‘my-component’, styleUrl: ‘my-component.css’, shadow: true }) export class MyComponent { @Prop() first: string; Decorators #Devoxx #WebComponents

Some concepts @Prop() first: string; @Prop() middle: string; @Prop() last: string; @State() nickname: string; Properties and States #Devoxx #WebComponents

Some concepts render() { return <div>Hello, World! I’m {this.getText()}</div>; } Asynchronous rendering using JSX #Devoxx #WebComponents

Some concepts @Prop() value: number; @Watch(value) valueChanged(newValue: boolean, oldValue: boolean) { console.log(The new value is ${newValue}, it was ${oldValue} before); } Watch #Devoxx #WebComponents

Some concepts @Event() actionCompleted: EventEmitter; someAction(message: String) { this.actionCompleted.emit(message); } @Listen(‘actionCompleted’) actionCompletedHandler(event: CustomEvent) { console.log(‘Received the custom actionCompleted event: ‘, event.detail); } Emitting events #Devoxx #WebComponents

Some concepts @Method() async sayHello() { this.hello = true; } render() { return ( <Host> <h2>{ this.hello ? Hello sthlm.js : ”}</h2> </Host> ); } Asynchronous public methods #Devoxx #WebComponents

Some concepts @Component({ tag: ‘my-component’, styleUrl: ‘my-component.css’, shadow: true }) export class MyComponent { Optional Shadow DOM #Devoxx #WebComponents

Coding my-stencil-counter #Devoxx #WebComponents

Simple. Fast. Web Components #Devoxx #WebComponents

Do you remember Polymer The first Web Component library #Devoxx #WebComponents

It is deprecated… And that means good news! #Devoxx #WebComponents

Let’s try to see clearer Let’s dive into Polymer history… #Devoxx #WebComponents

A tool built for another paradigm No web component support on browsers No React, Angular or Vue innovations #Devoxx #WebComponents

No so well suited for the current one The current platform is way more powerful The state of art has evolved #Devoxx #WebComponents

Let’s learn from its lessons The current platform is way more powerful The state of art has evolved #Devoxx #WebComponents

And let it rest… There will have no Polymer 4… #Devoxx #WebComponents

So Polymer as we know it is dead… But the Polymer Project is indeed alive! #Devoxx #WebComponents

But I have invested so much on it! What to do? #Devoxx #WebComponents

That’s why web components are top You can keep using all your Polymer components and create the new ones with a new library… And it simply works! #Devoxx #WebComponents

Born from the Polymer team For the new web paradigm #Devoxx #WebComponents

Modern lightweight web components For the new web paradigm #Devoxx #WebComponents

Based on lit-html An efficient, expressive, extensible HTML templating library for JavaScript #Devoxx #WebComponents

Do you know tagged templates? function uppercase(strings, …expressionValues) { var finalString = ” for ( let i = 0; i < strings.length; i++ ) { if (i > 0) { finalString += expressionValues[i - 1].toUpperCase() } finalString += strings[i] } return finalString } const expressions = [ ‘Sophia Antipolis’, ‘RivieraDev’, ‘Thank you’]; console.log(uppercaseJe suis à ${expression[0]} pour ${expression[1]}. ${expression[2]}! Little known functionality of template literals #Devoxx #WebComponents

lit-html Templates let myTemplate = (data) => html<h1>${data.title}</h1> <p>${data.body}</p>; Lazily rendered Generates a TemplateResult #Devoxx #WebComponents

It’s a bit like JSX, isn’t it? The good sides of JSX… but in the standard! #Devoxx #WebComponents

LitElement import { LitElement, html } from ‘lit-element’; // Create your custom component class CustomGreeting extends LitElement { // Declare properties static get properties() { return { name: { type: String } }; } // Initialize properties constructor() { super(); this.name = ‘World’; } // Define a template render() { return html<p>Hello, ${this.name}!</p>; } } // Register the element with the browser customElements.define(‘custom-greeting’, CustomGreeting); Lightweight web-components using lit-html #Devoxx #WebComponents

Coding my-lit-counter #Devoxx #WebComponents

Web Components & Frameworks Less “either/or” and more “both/and” #Devoxx #WebComponents

Compatibility is on Web Components side Web Components everywhere, baby! #Devoxx #WebComponents

They are the interoperable alternative Any framework… or no framework at all #Devoxx #WebComponents

You can have a single implementation And it simply works everywhere* #Devoxx #WebComponents

*React don’t fully support them yet Long story made short: use lit-labs/react #Devoxx #WebComponents

When you need interoperability Nothing beats the standard #Devoxx #WebComponents

Angular can generate web components Angular Elements #Devoxx #WebComponents

Vue can generate web components With defineCustomElement() #Devoxx #WebComponents

React can generate web components But it can generate them too #Devoxx #WebComponents

What about Svelte? Let’s look in detail one case #Devoxx #WebComponents

Web Components & Design Systems One of the best cases for Web Components #Devoxx #WebComponents

So, what are Design Systems? And why should I look at them? #Devoxx #WebComponents

A talk for devs by a dev I am not a designer, neither I play one on TV… #Devoxx #WebComponents

The same or different? #Devoxx #WebComponents

Style Guides A document listing the styles, patterns, practices, and principles of a brand design standards #Devoxx #WebComponents

Style Guides Style guides define the applicationʼs look and feel #Devoxx #WebComponents

Style Guide Example: Uber https://brand.uber.com/ #Devoxx #WebComponents

Style Guide Example: Medium https://www.behance.net/gallery/7226653/Medium-Brand-Development #Devoxx #WebComponents

Style Guides alone are ambiguous Interpretation needed to adapt the preconisation to the use case #Devoxx #WebComponents

Component Catalogs A component catalog is a repository of components, with one or several implementations, code examples and technical documentation #Devoxx #WebComponents

Component Catalog example: Bootstrap https://getbootstrap.com/ #Devoxx #WebComponents

Component Catalog Example: ING’s Lion https://lion-web-components.netlify.app/ #Devoxx #WebComponents

Catalogs alone create inconsistency Like using the same LEGO bricks to create very different objects #Devoxx #WebComponents

Design Systems A Design System is like a common visual language for product teams #Devoxx #WebComponents

Design systems A Design System is a set of design standards, documentations, and principles, alongside with the toolkit (UI patterns and code components) to achieve those standards #Devoxx #WebComponents

Design systems #Devoxx #WebComponents

Example: Carbon Design System https://www.carbondesignsystem.com/ #Devoxx #WebComponents

Example: Firefox’s Photon Design System https://design.firefox.com/photon/ #Devoxx #WebComponents

Example: Material Design https://material.io/ #Devoxx #WebComponents

The component catalog The poor relative of the Design System family #Devoxx #WebComponents

Let’s choose a simple example Bootstrap based component catalogs #Devoxx #WebComponents

A long time ago Components defined in HTML, CSS and some jQuery #Devoxx #WebComponents

Then it was AngularJS time… And new reference implementations were needed #Devoxx #WebComponents

But you know the sad story… All UI Bootstrap based catalogs woke up with an obsolete implementation #Devoxx #WebComponents

Worry no more, let’s do Angular! ng-bootstrap to the rescue #Devoxx #WebComponents

But times had changed… In 2017 Angular is only one more in the clique #Devoxx #WebComponents

TM React is the new Big Thing So let’s build React Bootstrap… #Devoxx #WebComponents

Wait, what about Vue? We also need BootstrapVue #Devoxx #WebComponents

OK, I think you see my point… #Devoxx #WebComponents

Most Design System do a choice Either they choose a canonical implementation or they ship and maintain several implementations #Devoxx #WebComponents

Both choices are problematic Shipping only one implementation: Web dev ecosystem changes quickly and almost nobody keeps the same framework for years… #Devoxx #WebComponents

Both choices are problematic Shipping several implementations: You need to maintain all the implementation… and you still miss some others #Devoxx #WebComponents

Incomplete catalogs are problematic People will need to recode the components in their chosen framework… Coherence is not guaranteed!!! #Devoxx #WebComponents

Example: Carbon Design System #Devoxx #WebComponents

Web Components & Design Systems A match made in heaven #Devoxx #WebComponents

Compatibility is on Web Components side Web Components everywhere, baby! #Devoxx #WebComponents

Do you remember AngularJS? And all the code put in the trash bin when Angular arrived… #Devoxx #WebComponents

The pain of switching frameworks? Rewriting once again your code… #Devoxx #WebComponents

The impossibility of sharing UI code? Between apps written with different frameworks #Devoxx #WebComponents

Web Components change that In a clean and standard way #Devoxx #WebComponents

They are the interoperable alternative Any framework… or no framework at all #Devoxx #WebComponents

They are truly everywhere 🚀 🚀 Even in the spaaaaaaaace 🚀 #Devoxx #WebComponents

You can have a single implementation And it simply works everywhere #Devoxx #WebComponents

When you need interoperability Nothing beats the standard #Devoxx #WebComponents

But how to do it? Designing, developing and managing a catalog of Web Components #Devoxx #WebComponents

Learning from the best https://lion-web-components.netlify.app/ #Devoxx #WebComponents

Learning from the best https://github.com/CleverCloud/clever-components #Devoxx #WebComponents

What kind of components? From little atomic blocs to big smart components, and everything in between #Devoxx #WebComponents

A matter of size and complexity What kind(s) of components you want to build #Devoxx #WebComponents

Build from the bottom and go up Eat your own dog food #Devoxx #WebComponents

And how to choose the atoms? Flexibility and configurability are key #Devoxx #WebComponents

And how to choose the atoms? Encode often used patterns #Devoxx #WebComponents

And what about the molecules? Capitalize on your atoms Keep the flexibility and configurability #Devoxx #WebComponents

Big smart business components Encoding your business logic #Devoxx #WebComponents

Internal or external customers? Who are your target users? #Devoxx #WebComponents

Internal customers need off-the-shelf components A well defined and coherent look-and-feel #Devoxx #WebComponents

External customers need to be able to tweak Theming and customizing components #Devoxx #WebComponents

How to organize the catalog Packages, imports and pragmatism #Devoxx #WebComponents

A single repository Single source of truth for the catalog #Devoxx #WebComponents

Two schools of thought A packet per component or a global one #Devoxx #WebComponents

Two schools of thought Individual versioning vs global one #Devoxx #WebComponents

Driving-up adoption Making devs use your components #Devoxx #WebComponents

Think who are your target users Users of any framework current or future… #Devoxx #WebComponents

They aren’t used to your library And they shouldn’t need to be #Devoxx #WebComponents

Go the extra mile to drive up adoption So they don’t need to do it #Devoxx #WebComponents

Make it easy to use As easy as a HTML tag #Devoxx #WebComponents

Document every composant How to use, inputs/outputs, examples… #Devoxx #WebComponents

Documentation isn’t enough Storybook make adoption easy #Devoxx #WebComponents

Keeping a coherent writing style Write down your guidelines #Devoxx #WebComponents

I18n shouldn’t be an afterthought Prepare everything for internationalization #Devoxx #WebComponents

That’s all, folks! Thank you all! #Devoxx #WebComponents