Setting Up SSR with Vue 3

Introduction

Server-Side Rendering (SSR) is a powerful technique for improving the performance and SEO of your Vue.js applications. By rendering the application on the server, SSR allows for faster initial load times and better search engine visibility. This article provides a step-by-step guide to setting up SSR with Vue 3, ensuring your content is original and detailed, with clear explanations and examples.

Preparing Your Environment

Before setting up SSR with Vue 3, ensure you have the necessary tools installed. This includes Node.js, npm or yarn, and Vue CLI.

Example: Installing Necessary Tools

# Install Node.js and npm from the official website
$ npm install -g @vue/cli

# Verify the installation
$ node -v
$ npm -v
$ vue --version

Explanation

In the example above, we use npm to install the Vue CLI globally. This command-line interface simplifies the process of setting up and managing Vue projects.

Creating a Vue 3 Project

Create a new Vue 3 project using Vue CLI. This will serve as the foundation for setting up SSR.

Example: Creating a New Vue 3 Project

# Create a new Vue 3 project
$ vue create my-vue-ssr-app

# Navigate to the project directory
$ cd my-vue-ssr-app

# Add Vue 3 support if not added automatically
$ vue add vue-next

Explanation

In the example above, we create a new Vue project and navigate to the project directory. If Vue 3 support is not added automatically, we use the `vue add vue-next` command to enable Vue 3 features.

Setting Up the Server

Set up an Express server to handle SSR. This server will render your Vue.js application and send the fully rendered HTML to the client.

Example: Creating the Server

# Install necessary dependencies
$ npm install express vue-server-renderer @vue/server-renderer

# Create the server file (server.js)

// server.js
const express = require('express');
const { createBundleRenderer } = require('@vue/server-renderer');
const { createApp } = require('./src/main.js');
const server = express();

server.get('*', (req, res) => {
  const app = createApp();
  const renderer = createBundleRenderer(app, {
    template: require('fs').readFileSync('./index.template.html', 'utf-8')
  });

  renderer.renderToString((err, html) => {
    if (err) {
      return res.status(500).end('Internal Server Error');
    }
    res.end(html);
  });
});

server.listen(8080, () => {
  console.log('Server running at http://localhost:8080');
});

Explanation

In the example above, we set up an Express server to handle SSR. The `createBundleRenderer` function from `@vue/server-renderer` is used to render the Vue application to a string, which is then sent to the client as a fully rendered HTML page.

Configuring the Vue Application

Configure the Vue application to work with SSR. This involves creating a server entry point and modifying the client entry point.

Example: Creating Server and Client Entry Points

// src/main.js
import { createSSRApp } from 'vue';
import App from './App.vue';

export function createApp() {
  const app = createSSRApp(App);
  return { app };
}

// src/entry-client.js
import { createApp } from './main';

const { app } = createApp();

app.$mount('#app');

// src/entry-server.js
import { createApp } from './main';

export default function (context) {
  const { app } = createApp();
  return app;
}

Explanation

In the example above, we create separate entry points for the server and client. The `main.js` file exports a function to create the Vue app, while the `entry-client.js` and `entry-server.js` files handle the client-side and server-side entry points, respectively.

Handling Data Pre-fetching

To ensure that the necessary data is available both on the server and the client, we need to handle data pre-fetching. This involves fetching data on the server and embedding it into the HTML sent to the client.

Example: Fetching Data on the Server

// src/store.js
import { createStore } from 'vuex';

export function createStore() {
  return createStore({
    state: {
      items: []
    },
    actions: {
      fetchItems({ commit }) {
        return fetch('/api/items')
          .then(response => response.json())
          .then(items => {
            commit('setItems', items);
          });
      }
    },
    mutations: {
      setItems(state, items) {
        state.items = items;
      }
    }
  });
}

// src/entry-server.js
import { createApp } from './main';

export default function (context) {
  const { app, store } = createApp();

  return store.dispatch('fetchItems').then(() => {
    context.state = store.state;
    return app;
  });
}

Explanation

In the example above, the `fetchItems` action fetches data from an API and commits the data to the Vuex store. During server-side rendering, the `entry-server.js` file dispatches the `fetchItems` action and attaches the fetched data to the server context. This data is then sent to the client, allowing the client-side application to hydrate with the pre-fetched data.

Hydrating the Client-Side Application

After the server sends the rendered HTML to the client, Vue.js needs to "hydrate" the client-side application by attaching event listeners and making the application interactive. This process is called client-side hydration.

Example: Client-Side Hydration

// src/entry-client.js
import { createApp } from './main';

const { app, store } = createApp();

if (window.__INITIAL_STATE__) {
  store.replaceState(window.__INITIAL_STATE__);
}

app.mount('#app');

Explanation

In the example above, the client-side entry point initializes the Vue.js application and mounts it to the DOM. The `__INITIAL_STATE__` embedded in the HTML from the server is used to replace the client-side store's state, ensuring that the application hydrates with the pre-fetched data.

Fun Facts and Little-Known Insights

• Fun Fact: SSR can significantly improve the performance of applications on low-end devices and slow network connections by reducing the amount of JavaScript that needs to be executed on the client side.
• Insight: Combining SSR with static site generation (SSG) can create a hybrid approach, offering the benefits of both pre-rendering and dynamic rendering. This approach is especially useful for content-heavy sites that require frequent updates.
• Secret: By leveraging edge-side rendering (ESR) with SSR, you can further enhance performance by caching server-rendered pages at the edge, reducing latency and improving load times for users across different regions.

Conclusion

Setting up Server-Side Rendering (SSR) with Vue 3 is a powerful way to enhance the performance, SEO, and user experience of your web applications. By following this comprehensive guide and implementing best practices, you can ensure faster initial load times and improved user engagement. The active and supportive Vue.js community, combined with comprehensive documentation, ensures that you have all the resources needed to succeed in modern web development.