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Getting started

Vite is a tool to facilitate the development experience of modern web projects.

It provides:

  • a development server which allows, among other things, Hot Module Replacement 🔥 of generated code by taking advantage of ES modules.

  • a build command which uses Rollup .

How does Vite work?

By default, Vite uses an index.html file as your application's entry point.

html
<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <title>Vite Project</title>
  </head>
  <body>
    <div id="app"></div>
    <script type="module" src="./src/main.ts"></script>
  </body>
</html>

💻 Vite dev server

When you launch Vite in development with npx vite, it will launch an HTTP server on port 5173 and serve your index.html file by rewriting the urls of your <script> tags and assets.

Thus, a request to the address: curl http://localhost:5173 will return your file index.html with the following code.

html
<!DOCTYPE html>
<html lang="en">
  <head>
    <script type="module" src="/@vite/client"></script>
    <meta charset="UTF-8" />
    <title>Vite in Dev mode</title>
  </head>
  <body>
    <div id="app"></div>
    <script type="module" src="/src/main.ts"></script>
  </body>
</html>

The code returned by http://localhost:5173/src/main.ts is your compiled entry point script. The one returned by http://localhost:5173/@client/client corresponds to the script setting up a WebSocket between your browser and the Vite server. The latter allows the hot replacement of your code to optimize your development experience.

📦 Building for production

Finally, when you start building your code with npx vite build, Vite will rely on Rollup and generate an index.html file that looks like this.

html
<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <title>Vite Build</title>
    <script type="module" crossorigin src="/assets/index-aa676a50.js"></script>
    <link rel="stylesheet" href="/assets/index-3443e464.css">
  </head>
  <body>
    <div id="app"></div>
  </body>
</html>

How to integrate Vite into a Symfony application?

The operation of Vite is driven by the rewriting of the <script> and <link> tags, so it would be interesting to move this logic into Twig functions.

In Vite's configuration file, we define the app entry point of our application.

js
// vite.config.js
export default defineConfig({
  build: {
    rollupOptions: {
      app: './path/to/app.js',
    },
  },
})

And then refer to that entry point in our Twig templates.

html
<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <title>Vite Build</title>
    {{ vite_entry_script_tags('app') }}
    {{ vite_entry_link_tags('app') }}
  </head>
  <body>
    <div id="app"></div>
  </body>
</html>

Depending on the context of use (development or production) the Twig functions will return either a reference to the Vite development server or to static files generated after a build step.

For more info on integration see Backend integration.

vite-plugin-symfony and pentatrion/vite-bundle extensions.

The vite-plugin-symfony extension for Vite and the pentatrion/vite-bundle Symfony bundle work together to provide a solution for this integration.

The main function of vite-plugin-symfony is to generate an entrypoints.json file. Like the manifest.json file, it will contain all the information about our entry points for server-side processing. This file will return different content if your Vite development server is started or if your files have been compiled.

json
{
  "isProd": false,
  "viteServer": {
    "origin": "http://[::1]:5173",
    "base": "/build/"
  },
  "entryPoints": {
    "app": {
      "js": [
        "http://[::1]:5173/build/src/app.ts"
      ]
    }
  },
  "legacy": false
}
json
{
  "entryPoints": {
    "app": {
      "assets": [],
      "css": [
        "/build/assets/app-3443e464.css"
      ],
      "js": [
        "/build/assets/app-6f6529cf.js"
      ],
      "legacy": false,
      "preload": []
    }
  },
  "isProd": true,
  "legacy": false,
  "viteServer": false
}

The pentatrion/vite-bundle Symfony bundle will mainly provide the two Twig functions vite_entry_script_tags and vite_entry_link_tags. Under the hood, these two functions parse the generated entrypoints.json file and return the appropriate <script> and <link> tags.

twig
{{ vite_entry_script_tags('app') }}
{{ vite_entry_link_tags('app') }}
html
<script type="module" src="http://[::1]:5173/@vite/client"></script>
<script type="module" src="http://[::1]:5173/build/src/app.ts"></script>
html
<script type="module" crossorigin src="/assets/app-6f6529cf.js"></script>
<link rel="stylesheet" href="/assets/app-3443e464.css">

Now that we've seen the theory, let's see how to install all of this in your Symfony application!

Infrastructure Diagram

How does Vite work

Released under the MIT License.