import React from 'react'; import Document, { Head, Main, NextScript } from 'next/document'; import { ServerStyleSheets } from '@material-ui/styles'; import theme from '../components/theme'; class MyDocument extends Document { render() { return ( {/* PWA primary color */}
); } } MyDocument.getInitialProps = async 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. const sheets = new ServerStyleSheets(); const originalRenderPage = ctx.renderPage; ctx.renderPage = () => originalRenderPage({ enhanceApp: App => props => sheets.collect(), }); const initialProps = await Document.getInitialProps(ctx); return { ...initialProps, // Styles fragment is rendered after the app and page rendering finish. styles: [ {initialProps.styles} {sheets.getStyleElement()} , ], }; }; export default MyDocument;