React: handling from events

All.js

import React, { Component } from 'react';
import ReactDOM from 'react-dom';

class App extends Component {
 //konstruojam state
 constructor(props){
  super(props);
  //state body laikysime textarea turini
  this.state ={ 
   body:''
  }
  // tam kad pasiektume per this naudojam modeli bind 
  this.handleSubmit = this.handleSubmit.bind(this);
  this.handleChange = this.handleChange.bind(this);
 }
  

 handleSubmit(e){
  e.preventDefault(); //stop refresh after submit
  console.log(this.state.body);
 }  

 handleChange(e){
  //nustatome stato body lygų textarea turiniui
  this.setState({
   body: e.target.value
  })
 } 

 render() {
  return (
   <div className="container">
    ....
    <form onSubmit={this.handleSubmit}>
     <div className="form-group">
      <textarea 
       onChange={this.handleChange}
       className="form-control" 
       rows="5" 
       maxLength="140" 
       placeholder="whats up?" 
       required/>
     </div>   
     <input type="submit" value="Post" className="form-control" />      </form>       
    ....
   </div>
  );)}

export default App;

Rezultatas: