Include Alpine.js in a production environment

Reasons for using Alpine

Alpine.js describes itself as your new lightweight JavaScript framework and focuses on just that. With the features of Vue.js and an equally familiar syntax (thanks to @vue/reactivity), existing HTML code can be extended with a desired level of reactivity without greatly increasing the footprint of existing scripts.

Integration & First Steps

The integration of Alpine, taking into account data protection and current content security policies is as simple as it could be.

$ pnpm i alpinejs

In most cases, the recommended implementation in the documentation is sufficient. For an increased level of security, Alpine provides a dedicated build with @alpinejs/csp.

After installing the package, Alpine can be imported and initialized with the line window.Alpine.start().

import Alpine from "alpinejs";

window.Alpine = Alpine; // Optional for feedback within DevTools
window.Alpine.start();

Theoretically, Alpine can be used fully inline from this point. In the following example, a dropdown element is controlled with Alpine attributes.

<div class="dropdown" x-data="{open: false}">
  <button class="dropdown-head" x-on:click="open = !open">Hello</button>
  <div class="dropdown-body" x-cloak x-show="open" x-transition>
    World
  </div>
</div>

The x-cloak attribute for .dropdown-body is not mandatory, but prevents the component from flickering when the page is initially loaded.

Since elements such as dropdowns are often used multiple times on a page in the same context, the functionality can be optimized with global methods to the extent that the actual inline code turns out a bit leaner and clearer.

More flexibility with Alpine.data()

The Alpine.data() method allows reuse of x-data contexts within the application. This allows the dropdown element already presented to be redesigned as follows.

import Alpine from "alpinejs";

document.addEventListener("alpine:init", () => {
  Alpine.data("dropdown", () => ({
    open: false,
    toggle() {
      this.open = !this.open;
    },
  }));
});

window.Alpine.start();

<div class="dropdown" x-data="dropdown">
  <button class="dropdown-head" x-on:click="toggle">Hello</button>
  <div class="dropdown-body" x-cloak x-show="open" x-transition>
    World
  </div>
</div>

In this scenario, the open state and the onclick function are offloaded to the global method so that changes to the code can be made centrally, within the dropdown object.

Global and local scopes and x-data as utility

As illustrated by the dropdown example, global and local scopes can be used to create and manipulate context. This methodology can be established as a higher-level utility to control multiple elements simultaneously, or to define and order states in a uniform way.

In the aforementioned PHP environment, video content from a popular third-party provider was included, requiring user consent to share data. Using Alpine, I defined a method that loads and displays all of the user’s videos within the x-data scope videos if users agree to the data exchange.

Alpine.data("videos", () => ({
  show: false,
  embed: "https://www.youtube-nocookie.com/embed/",
  accept: "Allow YouTube content",
  decline: "Hide YouTube content",

  toggle() {
    this.show = !this.show;
  },

  src(id) {
    return this.show && this.embed + id;
  },

  text() {
    return !this.show ? this.accept : this.decline;
  },
}));

<div class="videos" x-data="videos">
  <!-- ... -->
  <div class="video">
    <div class="video-consent" x-show="!show" x-transition>...</div>
    <iframe
      class="video-frame"
      title="Video-Player"
      x-cloak
      x-bind:src="src('dQw4w9WgXcQ')"
      x-show="show"
      x-transition
    ></iframe>
    <button class="video-button" x-on:click="toggle" x-text="text"></button>
  </div>
  <!-- ... -->
</div>

In principle, this concept can be modularized and optimized for different third parties, so that one methodology can be applied to multiple cases.

Findings

Complex and multi-used functions can be grouped into a context and made accessible to child elements through x-data. The ability to write and test scripts within Alpine attributes invites experimentation, but is unsuitable for a production environment. Functions and methods can instead be defined within the 'alpine:init' EventListener to reduce HTML document load time and complexity.

Global events and elements can be managed excellently via a context in the <html> element, as this is due to all child elements.

<html lang="en" x-data="utility"></html>

However, the global context does not block the use of other contexts within the HTML structure. This allows two contexts to be available within one element.

<html lang="en" x-data="utility">
  <!-- ... -->
  <div class="videos" x-data="videos"></div>
  <!-- ... -->
</html>

Thus for each HTML component an own context with functions and data can be established, which has also access to superordinate context and is not excluded from global settings.

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TL;DR

Alpine allows the incremental extension with interactive and reactive elements by a reduced approach and a methodology, which - thanks to a clear documentation - can be quickly taken up and established.