react-onblur

react-onblur

HOC for Blur (Unfocus) event handling of React component

Installation

npm i --save react-onblur

What is it?

It is simple HOC function

import withOnBlur from "react-onblur";
// ...
export default withOnBlur(/* args */)(YourReactComponent);

which puts in your component two extra props

setBlurListener: function (callbackOrOptions: Function(event) or Object[, once: Boolean])

unsetBlurListener: function ()

setBlurListener should be called when you want to add events to document.

• callbackOrOptions: Function or Object.
  • If it is Function, then it will be called (with event arg) once your component is unfocused or a user clicks outside of your component.
  • If it is Object of options, then it can contain there options:
    • onBlur: Function(event), required. It will be called once your component is unfocused or a user clicks outside of your component.
    • once: Boolean, optional. The same that second argument of this function.
    • checkInOutside: Function(domNode, isOutside): Boolean, optional. This function will be called always, when each of selected events are fired (e.g. when a user clicks on element on page or press key). It takes dom element target of an event and a Boolean sign that this element is outside. It should return Boolean value as sign that this element is outside. If it returns true then onBlur will be called. More information in next part of this doc.
• once: Boolean. If true then unsetBlurListener will be called after callback once your component is unfocused or a user clicks outside of your component.
• getRootNode: Function(this). Should return parent node, all targets out of this node will handle 'onBlur'.

unsetBlurListener should be called when your want to remove events from document.

(!!!) unsetBlurListener will be called in componentWillUnmount always.

TODO

How can you use it?

You should create new component:

import React, { PureComponent } from "react";
import withOnBlur from "react-onblur";

class DemoComponent extends PureComponent {
  state = {
    isOpened: false
  };

  componentDidUpdate(prevProps, prevState) {
    const { isOpened } = this.state;
    // `setBlurListener` and `unsetBlurListener` props were added by withOnBlur
    const { setBlurListener, unsetBlurListener } = this.props;

    if (isOpened !== prevState.isOpened) {

      // if our list was opened, then we will add listeners,
      if (isOpened) setBlurListener(this.onBlur);
      // else we will remove listeners
      else unsetBlurListener();

      // or
      // if (isOpened) setBlurListener(this.onBlur, true);

      // or
      // if (isOpened) setBlurListener({ onBlur: this.onBlur, once: true })
    }
  }

  onClickOpen = () => this.setState({ isOpened: true });
  onBlur = () => this.setState({ isOpened: false });

  render() {
    return (
      <div>
        <button onClick={this.onClickOpen}>
          Open list
        </button>
        {this.state.isOpened && (
          <ul>
            // ... list items
          </ul>
        )}
      </div>
    );
  }
}

export default withOnBlur({ debug: true })(DemoComponent);

Next, you can use this component in your App:

  function App() {
    return (
      <div className="App">
        <div>
          <button>Outside button</button>
        </div>
        <DemoComponent />
        <div>
          <button>Second outside button</button>
        </div>
      </div>
    );
  }

HOC function arguments

args	type	default	description
listenClick	bool	true	when true will add mousedown event for document
listenTab	bool	true	when true will add keyup and keydown listeners for document to check Tab key press
listenEsc	bool	true	when true will add keydown event for document to check Esc key is pressed
debug	bool	false	when true will write debug messages to console
autoUnset	bool	false	if true then unsetBlurListener will be called after callback action call once your component is unfocused or user will click outside of your component

Example

import withOnBlur from "react-onblur";
// ...
export default withOnBlur({
  listenClick: true,
  listenTab: false,
  debug: true,
  autoUnset: true
})(YourReactComponent);

What is checkInOutside? And why you should use it?

If you use ReactDOM.createPortal then you can put element to another parent and it will not be child by DOM tree. But you can use checkInOutside to say about it to react-onblur.

import React, { PureComponent } from "react";
import ReactDOM from 'react-dom';
import withOnBlur, { isDomElementChild } from "react-onblur";

class DemoPortalComponent extends PureComponent {
  state = {
    isOpened: false
  };

  domMenu = React.createRef();

  componentDidUpdate(prevProps, prevState) {
    const { isOpened } = this.state;
    const { setBlurListener, unsetBlurListener } = this.props;
    if (isOpened && isOpened !== prevState.isOpened) {
      setBlurListener({
        checkInOutside: this.checkInOutside,
        onBlur: this.onBlur,
        once: true
      })
    }
  }

  onClickOpen = () => this.setState({ isOpened: true });

  onBlur = () => this.setState({ isOpened: false });

  checkInOutside = (element, isOutside) => (
    // if it is in outside then we should check that it is not in our list,
    // which was moved to body by createPortal
    // For it we can use `isDomElementChild(parent, node)` from `react-onblur`
    // and if element is child of list then it returns false.
    isOutside && !isDomElementChild(this.domMenu.current, element)
  );

  render() {
    return (
      <div>
        <button onClick={this.onClickOpen}>
          Open list
        </button>
        {this.state.isOpened && (
          ReactDom.createPortal(
            <ul ref={this.domMenu}>
              // ... list items
            </ul>,
            document.querySelector('body')
          )
        )}
      </div>
    );
  }
}

export default withOnBlur()(DemoPortalComponent);

isDomElementChild

Check that node is child of parent.

isDomElementChild: Function(parent: DomNode, node: DomNode): Boolean

import withOnBlur, { isDomElementChild } from "react-onblur";

isDomElementChild(document.querySelector('body'), document.querySelector('div'));
// true for <body><div>1</div></body>

Demo GIF

Demo video

https://monosnap.com/file/gUeMnlLBE29xKzytdXsxBcZOtkpEtm

Example sandbox

https://codesandbox.io/embed/n9r236n2xl

Live Demo

https://n9r236n2xl.codesandbox.io/