This is a work in progress and it's practially verbatim extracted from a project I was doing, not really production-ready, and the API is very confusing, use at your own risk. It's also completely untested.

My motivation to make this library was to be able to use any kind of component from any framework on an Eleventy site with static rendering and progressive partial hydration (hydrate only the components that need hydration as they become visible in the page).

The lib/render folder files are more a wish-list than real files, right now only Preact and Nunjucks are actually written. I'll separate each renderer to a different repository in the near future.

$ yarn add render-hydratable

On /src/components/Person.js

const { h } = require('preact')
const { html } = require(`htm/preact`)

const Person = ({name, age}) => html`
  <button onClick=${() => console.log(name, age)}>
    ${name} is ${age} years old
  </button>
`

Person.hydratable = true

module.exports = Person

Then directly on JavaScript

const renderHydratable = require('render-hydratable/lib/render-hydratable')
const components = renderHydratable([`${__dirname}/src/components`])

components('Person', {name: "Bob", age: 27})

Or on .eleventy.js as a shortcode

config.addShortcode(
    'renderHydratable',
    renderHydratable([`${__dirname}/src/components`])
  )

If the component is marked as hydratable, then it will additionally render the following hydration marker before the component:

<script
  data-component="Person"
  data-props="{\"name\":\"Bob\",\"age\":27}"
  data-strategy="preact"
></script>

Technically it support hydrating with multiple frameworks on the same page.

On main JS file

const rehydration = require('render-hydratable/lib/rehydration')

// In the future my intention is to generate this automatically from the
// components used on the site
const componentsMap = {
  Person: require('./components/Person'),
}

// Also this from the frameworks used on the site
const strategies = {
  preact: require('render-hydratable/lib/render/with-preact').rehydrate,
}