use-a-ref-to-autofocus-an-input.md

Use A Ref To Autofocus An Input

When creating highly interactive interfaces with React, we are trying to make the user's experience of our app as smooth as possible. This means that when an edit button reveals an input field, we want that field to be in focus so that the user can immediately start typing.

This is a great use for React's ref prop. When you supply your component with a function as the ref prop, that function will be called with a reference to itself on mount and with null on unmount.

class MyAutofocusInput extends React.Component {
  focusInput = (component) => {
    if (component) {
      component.focus();
    }
  };

  render() {
    return (
      <input
        ref={this.focusInput}
        value={this.props.value}
        onChange={this.props.onChange}
      />
    );
  }
}

When this component gets rendered, the input will be focused via our focusInput function.

Note: refs only work with class components, so don't try to use it with a functional component.

See Refs and the DOM in React's documentation for more details.