Method getInitialProps

stepped-solutions/10/_document.js:5–12

({ renderPage })

export default class MyDocument extends Document {
  static getInitialProps({ renderPage }) {
    const sheet = new ServerStyleSheet();
    const page = renderPage((App) => (props) =>
      sheet.collectStyles(<App {...props} />)
    );
    const styleTags = sheet.getStyleElement();
    return { ...page, styleTags };
  }

  render() {
    return (