Are Web Components the Betamax of web development?

24-25 September, 2019

24-25 September, 2019 Are Web Components the Betamax of web development? Horacio Gonzalez @LostInBrittany

Who are we? Introducing myself and introducing OVH

Horacio Gonzalez @LostInBrittany Spaniard lost in Brittany, developer, dreamer and all-around geek

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The 3 minutes context What the heck are web component?

Web Components Web standard W3C

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

Web Components Create your own HTML tags Encapsulating look and behavior

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

Web Components CUSTOM ELEMENTS SHADOW DOM 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>

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>

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);

But in fact, it’s just an element… ● ● ● ● Attributes Properties Methods Events

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

On Web Components tour since 2014

Image: bu.edu Web components == Revolution

Images: BitRebels & Brickset Building a world brick by brick

Is the promise unfulfilled? It’s 2019 now, where is your revolution, dude?

And, even worse, several months ago Hey, dude, your Web Components thing is like Betamax Even if it was a better solution, market has already chosen, React has won, as VHS did…

Hey, old man, WTF is a Betamax? A videocassette guide for Millenials

At the beginning there was the TV And public saw it was good…

But how to keep your favorite show forever? Sony VTR CV-2000 - Image credit LabGuy’s World The VTR was born, somewhere in the 1960s

From videotape to videocassette… Sony U-matic - Image credit MKH Electronics U-matic cassette - Image credit PSAP And then to mass market, sometime in the 1970s

Each vendor proposed their solution Sony’s Betamax - Image credit PSAP JVC’s VHS - Image credit PSAP Cassettes aren’t so different from JS frameworks after all…

There was a format war So fierce that it has its own Wikipedia page

Betamax was a superior format Higher quality recorders, better resolution, slightly superior sound, and more stable image

But the market decided otherwise And Betamax, even if superior, failed…

As usual, the winner took it all Until a new arrival entered in scene, the DVD… But that’s another story for another talk

Why did Betamax failed? Spoiler: it isn’t so simple…

Betamax was believed to be superior In the minds of the public and press

But consumers wanted an affordable VCR Betamax costed hundreds of dollars more

They also wanted to record a full movie Originally Betamax cassettes only recorded 1 hour

And compatibility weighted on VHS side Many licencees offered VHS VCRs

Are Web Components like Betamax? A perceived superior alternative destined to fail?

It could be even the opposite… Web components are maybe the VHS of JS

Compatibility is on Web Components side Web Components everywhere, baby!

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

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

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

Web Components change that In a clean and standard way

They are indeed a revolution But it’s a silent one…

They are there, in everyday sites More than you can imagine

The components architecture won Components, components everywhere

Web components ARE platform Truly part of the platform…

Aren’t the multiple Web Components libs a sign of failure? If the standard worked, people would use Vanilla, wouldn’t them?

Web component standard is low level At it should be!

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

Libraries are helpers They give you higher-level primitives

Different high-level primitives Each one tailored to a use

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

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

Stencil Powering Ionic 4

Not another library A Web Component compiler

Not a beta anymore Ionic 4 released, powered by Stencil!

A build time tool To generate standard web components

Fully featured ● Virtual DOM ● Async rendering ● Reactive data-binding ● TypeScript ● JSX

And the cherry on the cake Server-Side Rendering

Polymer Is the old player still alive?

Polymer evolved again in 2018 Image: © Nintendo Polymer 3 was here!

What’s Polymer status today? Well, how could I say… it’s complicated

It seems it’s going to be deprecated… Technically yes… and that means good news!

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

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

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

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

And let it rest… There will have no Polymer 4…

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

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

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!

And without metaphors? Polymer Project != Polymer library Polymer Project well alive Polymer library was only one library

LitElement New kid on the block

Born from the Polymer team For the new web paradigm

Modern lightweight web components For the new web paradigm

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

Do you know tagged templates? function uppercaseExpression(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 = [ ‘Tours’, ‘Touraine Tech’, ‘Thank you’]; console.log( uppercaseExpressionI am so happy to be in ${expressions[0]} for ${expressions[1]} again! ${expressions[2]}, ${expressions[1]}! ) Little known functionality of template literals

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

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

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

One more thing…* Let’s copy from the master

Polymer is not important WebComponents ARE

Use the Platform, Luke… WebComponents ARE native

Do you love your framework? Oh yeah, we all do

Would you marry your framework? Like until death…

How much does cost the divorce? Do you remember when you dropped AngularJS for Angular?

Why recode everything again? Reuse the bricks in your new framework

Lots of web components libraries LitElement SkateJS For different need and sensibilities

And some good news Angular Elements Vue Web Component Wrapper Frameworks begin to understand it

So for your next app Choose a framework, no problem… But please, help your future self Use Web Components!

Conclusion That’s all, folks!