title: Why ref='string' is "legacy"?
body: <p>In the React documentation they say:</p>
  
  <blockquote>
    <p>React also supports using a string (instead of a callback) as a ref prop on any component, although <strong>this approach is mostly legacy</strong> at this point.</p>
  </blockquote>
  
  <p><a href="https://facebook.github.io/react/docs/more-about-refs.html" rel="noreferrer">https://facebook.github.io/react/docs/more-about-refs.html</a></p>
  
  <p>Take the following example:</p>
  
  <pre><code>class Foo extends Component {
    render() {
      return &lt;input onClick={() =&gt; this.action()} ref={input =&gt; (this._input = input)} /&gt;;
    }
    action() {
      console.log(this._input.value);
    }
  }
  </code></pre>
  
  <p>Why should I prefer this, instead of:</p>
  
  <pre><code>class Foo extends Component {
    render() {
      return &lt;input onClick={() =&gt; this.action()} ref='input' /&gt;;
    }
    action() {
      console.log(this.refs.input.value);
    }
  }
  </code></pre>
  
  <p>?</p>
  
  <p>It seems just much more clean and easier the second example.<br>
  Are there risks that the string method will be deprecated?</p>
  
  <p><br>
  <em><strong>NB</strong>: I'm looking for the "official" answer to the statement in the documentation, I'm not asking about personal preferences and so on.</em></p>