pages/_document.js
import React from 'react'
import PropTypes from 'prop-types'
import Document, { Head, Main, NextScript } from 'next/document'
import flush from 'styled-jsx/server'
class MyDocument extends Document {
render () {
const { pageContext } = this.props
return (
<html lang="en" dir="ltr">
<Head>
<meta charSet="utf-8" />
{/* Use minimum-scale=1 to enable GPU rasterization */}
<meta
name="viewport"
content="minimum-scale=1, initial-scale=1, width=device-width, shrink-to-fit=no"
/>
<link rel="shortcut icon" href="/static/favicon.ico"/>
{/* PWA primary color */}
<meta
name="theme-color"
content={pageContext ? pageContext.theme.palette.primary.main : null}
/>
<link
rel="stylesheet"
href="https://fonts.googleapis.com/css?family=Roboto:300,400,500"
/>
<link href="https://fonts.googleapis.com/css?family=Montserrat:400,500,600,700,800" rel="stylesheet" />
</Head>
<body>
<Main />
<NextScript />
</body>
</html>
)
}
}
MyDocument.getInitialProps = ctx => {
// Resolution order
//
// On the server:
// 1. app.getInitialProps
// 2. page.getInitialProps
// 3. document.getInitialProps
// 4. app.render
// 5. page.render
// 6. document.render
//
// On the server with error:
// 1. document.getInitialProps
// 2. app.render
// 3. page.render
// 4. document.render
//
// On the client
// 1. app.getInitialProps
// 2. page.getInitialProps
// 3. app.render
// 4. page.render
// Render app and page and get the context of the page with collected side effects.
let pageContext
const page = ctx.renderPage(Component => {
const WrappedComponent = props => {
pageContext = props.pageContext
return <Component {...props} />
}
WrappedComponent.propTypes = {
pageContext: PropTypes.object.isRequired
}
return WrappedComponent
})
let css // It might be undefined, e.g. after an error.
if (pageContext) {
css = pageContext.sheetsRegistry.toString()
}
return {
...page,
pageContext, // Styles fragment is rendered after the app and page rendering finish.
styles: (
<React.Fragment>
<style
id="jss-server-side" // eslint-disable-next-line react/no-danger
dangerouslySetInnerHTML={{ __html: css }}
/>
{flush() || null}
</React.Fragment>
)
}
}
export default MyDocument