ReactJS - Clear select value on focus

Question

I need to clear the selected value of select dropdown as soon as user focus on the select element. I have used the below code but cant figure out what property of select do I need to reset.

<select name="select1" onChange={this.onChangeOption} onFocus={this.handleFocus}>
    <option value=''>Please select...</option>
    <option value='A'>A</option>
    <option value='B'>B</option>
    <option value='C'>C</option>
    <option value='D'>D</option>
</select>

handleFocus(event) {
    event.target.select(); // it did not work!!
}

I want the selected value to be Please select... when the user focuses on the element.

Answer 1

One of the problems with your select element is that it's neither a controlled or an uncontrolled input element. What you want to achieve can be done with both methods, and it looks like you attempted to make a controlled component.

I'll provide a solution for both:

---

Clearing a controlled <select> element

You need to turn your select element into a controlled component by assigning it a value which is controlled by the state. Then, make your handleFocus function reset that state variable.

For example:

class MyApp extends React.Component {
  constructor() {
    super();
    this.state = {select: ''};
  }
  
  onChangeOption = (event) => {
    this.setState({select: event.target.value});
  }
  
  handleFocus = (event) => {
    this.setState({select: ''});
  }
 
  render() {
    return (
      <select name="select1" value={this.state.select} onChange={this.onChangeOption} onFocus={this.handleFocus}>
        <option value=''>Please select...</option>
        <option value='A'>A</option>
        <option value='B'>B</option>
        <option value='C'>C</option>
        <option value='D'>D</option>
    </select>
    );
  }
}
 
ReactDOM.render(<MyApp />, document.getElementById("app"));

<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react-dom.min.js"></script>
<div id="app"></div>

---

Clearing an uncontrolled <select> element

If you want to let the DOM manage the select element you could do the following to clear the value whenever the focus event is fired.

class MyApp extends React.Component {
  
  handleFocus = (event) => {
    event.target.value = '';
  }
 
  render() {
    return (
      <select name="select1" onFocus={this.handleFocus}>
        <option value=''>Please select...</option>
        <option value='A'>A</option>
        <option value='B'>B</option>
        <option value='C'>C</option>
        <option value='D'>D</option>
    </select>
    );
  }
}
 
ReactDOM.render(<MyApp />, document.getElementById("app"));

<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react-dom.min.js"></script>
<div id="app"></div>