---
id: refs-and-the-dom
title: Refs and the DOM
redirect_from:
  - "docs/working-with-the-browser.html"
  - "docs/more-about-refs.html"
  - "docs/more-about-refs-ko-KR.html"
  - "docs/more-about-refs-zh-CN.html"
  - "tips/expose-component-functions.html"
  - "tips/children-undefined.html"
permalink: docs/refs-and-the-dom.html
---

In the typical React dataflow, [props](/react/docs/components-and-props.html) are the only way that parent components interact with their children. To modify a child, you re-render it with new props. However, there are a few cases where you need to imperatively modify a child outside of the typical dataflow. The child to be modified could be an instance of a React component, or it could be a DOM element. For both of these cases, React provides an escape hatch.

## The ref Callback Attribute

React supports a special attribute that you can attach to any component. The `ref` attribute takes a callback function, and the callback will be executed immediately after the component is mounted or unmounted.

When the `ref` attribute is used on an HTML element, the `ref` callback receives the underlying DOM element as its argument. For example, this code uses the `ref` callback to store a reference to a DOM node:

```javascript{8,9,19}
class CustomTextInput extends React.Component {
  constructor(props) {
    super(props);
    this.focus = this.focus.bind(this);
  }

  focus() {
    // Explicitly focus the text input using the raw DOM API
    this.textInput.focus();
  }

  render() {
    // Use the `ref` callback to store a reference to the text input DOM
    // element in this.textInput.
    return (
      <div>
        <input
          type="text"
          ref={(input) => { this.textInput = input; }} />
        <input
          type="button"
          value="Focus the text input"
          onClick={this.focus}
        />
      </div>
    );
  }
}
```

React will call the `ref` callback with the DOM element when the component mounts, and call it with `null` when it unmounts.

Using the `ref` callback just to set a property on the class is a common pattern for accessing DOM elements. If you are currently using `this.refs.myRefName` to access refs, we recommend using this pattern instead.

When the `ref` attribute is used on a custom component, the `ref` callback receives the mounted instance of the component as its argument. For example, if we wanted to wrap the `CustomTextInput` above to simulate it being clicked immediately after mounting:

```javascript{3,9}
class AutoFocusTextInput extends React.Component {
  componentDidMount() {
    this.textInput.focus();
  }

  render() {
    return (
      <CustomTextInput
        ref={(input) => { this.textInput = input; }} />
    );
  }
}
```

You may not use the `ref` attribute on functional components because they don't have instances. You can, however, use the `ref` attribute inside the `render` function of a functional component:

```javascript{2,3,6,13}
function CustomTextInput(props) {
  // textInput must be declared here so the ref callback can refer to it
  let textInput = null;

  function handleClick() {
    textInput.focus();
  }

  return (
    <div>
      <input
        type="text"
        ref={(input) => { textInput = input; }} />
      <input
        type="button"
        value="Focus the text input"
        onClick={handleClick}
      />
    </div>
  );  
}
```

### Don't Overuse Refs

Your first inclination may be to use refs to "make things happen" in your app. If this is the case, take a moment and think more critically about where state should be owned in the component hierarchy. Often, it becomes clear that the proper place to "own" that state is at a higher level in the hierarchy. See the [Lifting State Up](/react/docs/lifting-state-up.html) guide for examples of this.