blog.js

import { Component } from 'react'
import Header from '../components/Header'

export default class extends Component {
  static getInitialProps () {
    return { data: 'My personal blog' }
  }

  render () {
    return (
      <div>
        <Header />
        <p>{this.props.data}</p>
      </div>
    )
  }
}