An all in one preset for writing Preact apps with the vite bundler.
Features:
- Sets up Hot Module Replacement via prefresh
- Enables Preact Devtools bridge during development
- Aliases React to
preact/compat
First intall the preset package from npm:
npm install --save-dev @preact/preset-vite
# or
yarn add -D @preact/preset-viteEnhance your vite config with the Preact preset plugin in your vite.config.ts or vite.config.js:
import { defineConfig } from "vite";
import preact from "@preact/preset-vite";
export default defineConfig({
plugins: [preact()]
});Options can be passed to our preset plugin via the first argument:
export default defineConfig({
plugins: [
preact({ devtoolsInProd: true })
]
});| Option | Type | Default | Description |
|---|---|---|---|
devtoolsInProd |
boolean |
false |
Inject devtools bridge in production bundle instead of only in development mode |
devToolsEnabled |
boolean |
true |
Inject devtools bridge |
prefreshEnabled |
boolean |
true |
Inject Prefresh for HMR |
reactAliasesEnabled |
boolean |
true |
Aliases react, react-dom to preact/compat |
babel |
object |
See Babel configuration | |
prerender |
object |
See Prerendering configuration |
The babel option lets you add plugins, presets, and other configuration to the Babel transformation performed on each JSX/TSX file.
preact({
babel: {
presets: [...],
// Your plugins run before any built-in transform (eg: Fast Refresh)
plugins: [...],
// Use .babelrc files
babelrc: true,
// Use babel.config.js files
configFile: true,
}
})| Option | Type | Default | Description |
|---|---|---|---|
enabled |
boolean |
false |
Enables prerendering |
renderTarget |
string |
"body" |
Query selector for where to insert prerender result in your HTML template |
prerenderScript |
string |
undefined |
Absolute path to script containing exported prerender() function. If not provided, will try to find the prerender script in the scripts listed in your HTML entrypoint |
additionalPrerenderRoutes |
string[] |
undefined |
Prerendering will crawl your site automatically, but you'd like to prerender some pages that may not be found (such as a /404 page), use this option to specify them |
To prerender your app, you'll need to do these things:
- Enable prerendering in the plugin options
- Specify your render target, if you want the HTML to be inserted anywhere other than the
document.body. This location likely should matchrender(), i.e.,render(<App />, document.querySelector('#app'))->'#app' - Create and export a
prerender()function from a script. You could add this to your app entrypoint or create a completely separate file for it, either will work. See below for a usage example - Specify where your
prerender()function is by either a) adding aprerenderattribute to the script tag that contains it in your entry HTML (<script prerender src="./my-prerender-script.js">) or b) use theprerenderScriptplugin option to specify the location with an absolute path
The plugin simply calls the prerender function you provide so it's up to you to determine how your app should be prerendered. You'll likely want to use preact-render-to-string, or a wrapper around it such as preact-iso's prerender, but whatever you choose, the minimum you'll need to return is an object containing an html property with your HTML string which will then be inserted according to your renderTarget.
Your prerender() function can be asynchronous, so feel free to make HTTP requests to retrieve data (fetch(...)), read files from disk (fs.readFile(...)), or similar things to set up your app.
For a full example implementation, see our demo
import { prerender as ssr } from 'preact-iso';
function App() {
return <h1>Hello World!</h1>
}
export async function prerender(data) {
const html = ssr(<App />);
return {
html,
// Optionally add additional links that should be
// prerendered (if they haven't already been)
links: new Set(['/foo', '/bar']),
// Optionally configure and add elements to the `<head>` of
// the prerendered HTML document
head: {
// Sets the "lang" attribute: `<html lang="en">`
lang: 'en',
// Sets the title for the current page: `<title>My cool page</title>`
title: 'My cool page',
// Sets any additional elements you want injected into the `<head>`:
// <link rel="stylesheet" href="foo.css">
// <meta property="og:title" content="Social media title">
elements: new Set([
{ type: 'link', props: { rel: 'stylesheet', href: 'foo.css' } },
{ type: 'meta', props: { property: 'og:title', content: 'Social media title' } }
])
}
};
}MIT, see the license file.