NewTodo.js

import React, { Component } from 'react';
import '../NewTodo.css';
import { Redirect } from 'react-router-dom';

class NewTodo extends Component {
    state = {
        title: '',
        content: '',
        submitted: false,
    }
    render() {
        if (this.state.submitted) {
            return <Redirect to='/todos' />
        }
        return (
            <div className="NewTodo">
                <h1>Add a Todo</h1>
                <label>Title</label>
                <input type="text" value={this.state.title}
                        onChange={(event) => this.setState({ title: event.target.value })} />
                <label>Content</label>
                <textarea rows="4" type="text" value={this.state.content}
                        onChange={(event) => this.setState({ content: event.target.value })} />
                <button onClick={() => this.postTodoHandler()}>Submit</button>
            </div>
        );
    }
    postTodoHandler = () => {
        const data = 
            { title: this.state.title, content: this.state.content };
        alert('Submitted\n' + data.title + '\n' + data.content);
        this.setState( {submitted: true} );
        this.props.history.push('/todos');
    }
};
export default NewTodo;