Adding todo items

In the TodoApp component, we'll add a text input that allows the user to enter new todo items. When they're done entering the todo, Relay will need to send a mutation to the backend GraphQL server. Here's what the component code looks like:

import React, { Component, PropTypes } from 'react'; 
import { 
  View, 
  TextInput, 
} from 'react-native'; 
import Relay from 'react-relay'; 
 
import styles from './styles'; 
import AddTodoMutation from './mutations/AddTodoMutation'; 
import TodoList from './TodoList'; 
 
export class TodoRelayMobile extends Component { 
  static propTypes = { 
    viewer: PropTypes.any.isRequired, 
    relay: PropTypes.shape({ 
      commitUpdate: PropTypes.func.isRequired, 
    }), 
  } 
 
  // We need to keep track of new todo item text 
  // as the user enters them. 
  state = { 
    text: '', 
  } 
 
  // When the user creates the todo by pressing enter, 
 ...