react fade in modal code example

Example: modal styled components

import React, { Component } from "react";import ReactDom from "react-dom";import PropTypes from "prop-types";// styledimport StyledModal from "./Modal.css";const modalRoot = document.getElementById("modal-root");class Modal extends Component {  static defaultProps = {    id: "",    modalClass: "",    modalSize: "md"  };static propTypes = {    id: PropTypes.string.isRequired,    onClose: PropTypes.func.isRequired,    isOpen: PropTypes.bool.isRequired,    modalClass: PropTypes.string,    modalSize: PropTypes.string  };state = { fadeType: null };background = React.createRef();componentDidMount() {    window.addEventListener("keydown", this.onEscKeyDown, false);    setTimeout(() => this.setState({ fadeType: "in" }), 0);  }componentDidUpdate(prevProps, prevState) {    if (!this.props.isOpen && prevProps.isOpen) {      this.setState({ fadeType: "out" });    }  }componentWillUnmount() {    window.removeEventListener("keydown", this.onEscKeyDown, false);  }transitionEnd = e => {    if (e.propertyName !== "opacity" || this.state.fadeType === "in") return;if (this.state.fadeType === "out") {      this.props.onClose();    }  };onEscKeyDown = e => {    if (e.key !== "Escape") return;    this.setState({ fadeType: "out" });  };handleClick = e => {    e.preventDefault();    this.setState({ fadeType: "out" });  };render() {    return ReactDom.createPortal(      <StyledModal        id={this.props.id}        className={`wrapper ${this.props.class}`}        role="dialog"        modalSize={this.props.size}        onTransitionEnd={this.transitionEnd}        fadeType={this.state.fadeType}      >        <div className="box-dialog">          <div className="box-header">            <h4 className="box-title">Title Of Modal</h4>            <button onClick={this.handleClick} className="close">              ×            </button>          </div>          <div className="box-content">{this.props.children}</div>          <div className="box-footer">            <button onClick={this.handleClick} className="close">              Close            </button>          </div>        </div>        <div          className={`background`}          onMouseDown={this.handleClick}          ref={this.background}        />      </StyledModal>,      modalRoot    );  }}export default Modal;