title: React - TypeError: _this.setState is not a function
body: <p>I am playing with React and trying to save the text that user type to the input to the <code>state</code>. I have added to the textarea an <code>onChange</code> attribute for setting the state.</p>
  
  <p>However, when I start typing, I see error in the console stating <code>TypeError: _this.setState is not a function</code>.</p>
  
  <p>I've tried different ways of trying to fix it, but still don't have it.</p>
  
  <pre><code>const NewItemForm = props =&gt; (
      &lt;Form onSubmit={props.send_form}&gt;
          &lt;Form.Group&gt;
              &lt;TextArea 
                  placeholder='Name your first item here' 
                  name='item_msg'
                  onChange={e =&gt; this.setState({ item_msg: e.target.value })} /&gt;
              &lt;Form.Button primary content='Create Item' /&gt;
          &lt;/Form.Group&gt;
      &lt;/Form&gt;
  )
  
  class App extends Component {
      constructor () {
          super();
          this.state = {
            item_msg: ''
          }
      }
  
      handleSubmit(e){ 
          e.preventDefault();
  
          console.log(this.state.item_msg);  
      }  
  
      render() {
          return (
              &lt;div className="App"&gt;
                  &lt;MainHeaderr /&gt;
                  &lt;Container&gt;
                      &lt;NewItemForm send_form={this.handleSubmit.bind(this)} /&gt;
                  &lt;/Container&gt;
              &lt;/div&gt;
          );
      }
  }
  
  export default App;
  </code></pre>