Modern Monoliths: Building SPAs with Inertia.js and Laravel

Overview of the Inertia Approach

Building single-page applications (SPAs) often feels like managing two separate worlds: a complex JavaScript frontend and a robust PHP backend. Usually, this requires building a messy REST API and managing client-side routing, which adds significant overhead. Inertia.js solves this by acting as an adapter rather than a framework. It allows you to build fully client-side rendered SPAs using classic server-side routing and controllers. You get the snappy feel of a modern web app without the pain of manual state synchronization or token-based authentication.

Prerequisites

Before diving into the code, ensure you have a firm grasp of Laravel fundamentals, particularly routing and controllers. Since Inertia.js lets you use your favorite frontend tools, you should be comfortable with either Vue.js or React. You will also need Node.js and Composer installed on your local machine to manage dependencies.

Key Libraries & Tools

• Laravel Installer: The command-line utility for bootstrapping new projects.
• Laravel Breeze: A minimal starter kit that provides a perfect starting point for Inertia.js projects.
• Inertia Adapters: Specialized packages for Vue.js or React that bridge the gap between the backend and the frontend.

Code Walkthrough: Data Exchange

In a standard app, a link click reloads the whole page. Inertia.js intercepts these clicks and performs an AJAX request instead.

On the backend, your controller looks surprisingly familiar:

use Inertia\Inertia;

public function index()
{
    return Inertia::render('Dashboard', [
        'users' => User::all(),
    ]);
}

Instead of returning a Blade view, we use Inertia::render. This sends a JSON response containing the component name ('Dashboard') and the data (props). On the frontend, Inertia.js receives this data and swaps the current page component with the new one dynamically.

Syntax Notes & Best Practices

Always use the <Link> component provided by the Inertia.js library rather than standard <a> tags. Standard tags trigger a full browser refresh, defeating the purpose of the SPA.

import { Link } from '@inertiajs/vue3'

<Link href="/users">View Users</Link>

Tips & Gotchas

Don't try to use Inertia.js for public-facing websites where SEO is the top priority unless you implement Server Side Rendering (SSR). For internal dashboards and complex SaaS products, however, it shines. Remember that because Inertia.js shares the same session as your Laravel backend, you don't need to worry about OAuth or JWT for internal navigation. Use the standard Laravel auth guards you already know.