import React, { Component } from 'react'; import fs from 'fs'; import { App, AppRegistry, Window, TextInput, View } from 'proton-native'; class Notepad extends Component { state = { text: '' }; shouldComponentUpdate(nextProps, nextState) { if (typeof nextState.text === 'string') return false; // nextState is set from input else return true; // nextState is set from file } render() { return ( this.setState({ text })} value={this.state.text} style={{ flex: 1 }} multiline /> ); } } AppRegistry.registerComponent('notepad', );