Creating Single Page Applications (SPAs) with Vue.js — A Complete Beginner’s Guide

Chapter 1: Introduction to Single Page Applications and Vue.js

🧭 What You’ll Learn

In this chapter, you’ll gain a deep understanding of:

• What Single Page Applications (SPAs) are
• How SPAs differ from traditional multi-page apps
• The role of client-side routing and the History API
• Key benefits and trade-offs of using SPAs
• Why Vue.js is an ideal choice for building SPAs
• Real-world use cases and architecture overview

🌍 What Is a Single Page Application (SPA)?

A Single Page Application (SPA) is a web app that dynamically updates the browser’s content without reloading the entire page. Rather than making full-page reloads for each user action, SPAs rely on JavaScript to manipulate the DOM and fetch content asynchronously, delivering a smooth, app-like user experience.

🆚 SPA vs. Traditional Web Apps

🎯 Why Are SPAs So Popular?

The rise of web apps like Gmail, Twitter, Trello, and Notion demonstrates the power of SPAs.

✅ Benefits of SPAs:

• Fast navigation and reduced latency after initial load
• Better user experience, mimicking native apps
• No full-page reloads, resulting in fewer server requests
• Highly interactive UIs with real-time features
• Modular development using components

⚠️ Trade-offs:

• SEO challenges (can be addressed with SSR)
• Initial load time may be higher
• Client-side security and complexity can increase

🔧 How SPAs Work Under the Hood

• When a user visits the site, the initial HTML, CSS, and JS are loaded once.
• JavaScript frameworks like Vue.js take control of the DOM.
• Navigation between “pages” is handled internally using Vue Router, not the browser.
• The History API updates the URL in the address bar without triggering a page reload.
• Additional content is fetched via AJAX, fetch, or Axios calls.

🛠️ Code Sample: Changing URL with History API

js

history.pushState({}, '', '/about');

This updates the browser URL to /about without reloading the page—one of the core features SPAs rely on.

🧱 Anatomy of a Vue.js SPA

To build a full SPA with Vue.js, you need:

🎨 Visual Diagram of an SPA with Vue.js

bash

User → Browser → Vue App (HTML/CSS/JS loaded once)

                ↓

             Vue Router

             ↓        ↓

     /home → Home.vue | /about → About.vue

             ↓        ↓

          Axios → API (Optional)

📦 Installing Vue.js and Setting Up Your First SPA

We recommend using Vite for fast project setup with Vue 3:

🪜 Step-by-Step with Vite:

bash

npm create vite@latest my-spa -- --template vue

cd my-spa

npm install

npm run dev

This gives you:

• A working Vue.js app
• Fast hot-reloading dev server
• Built-in support for vue-router and modular components

🧩 Why Vue.js Is Ideal for SPAs

Vue.js is a progressive JavaScript framework—meaning you can scale it up or down depending on your needs. It’s declarative, reactive, and designed to simplify UI development.

✅ Features That Make Vue Great for SPAs:

• Component-based UI
• Built-in state and lifecycle management
• Official support for client-side routing (Vue Router)
• Lightweight and fast, with a smaller bundle size than React or Angular
• Simple API and gentle learning curve

🔤 Sample Vue Component

vue

<!-- components/Welcome.vue -->

<template>

  <h1>Welcome to my Vue SPA!</h1>

</template>

<script>

export default {

  name: 'Welcome'

}

</script>

🚦 Real-World Use Cases of Vue SPAs

💡 Key Terms Glossary

✅ Recap Checklist

Before moving to routing, make sure you understand:

• What a SPA is and how it differs from MPAs
• Why Vue.js is ideal for building SPAs
• How Vue handles DOM rendering and reactivity
• What Vue Router does in a SPA
• How to set up a basic Vue.js project with Vite