weseek__growi/src/client/js/components/LikeButton.jsx

import React from 'react';
import PropTypes from 'prop-types';

export default class LikeButton extends React.Component {

  constructor(props) {
    super(props);

    this.state = {
      isLiked: !!props.isLiked,
    };

    this.handleClick = this.handleClick.bind(this);
  }

  handleClick(event) {
    event.preventDefault();

    const pageId = this.props.pageId;

    if (!this.state.isLiked) {
      this.props.crowi.apiPost('/likes.add', {page_id: pageId})
      .then(res => {
        this.setState({isLiked: true});
      });
    }
    else {
      this.props.crowi.apiPost('/likes.remove', {page_id: pageId})
      .then(res => {
        this.setState({isLiked: false});
      });
    }
  }

  isUserLoggedIn() {
    return this.props.crowi.me !== '';
  }

  render() {
    // if guest user
    if (!this.isUserLoggedIn()) {
      return <div></div>;
    }

    const btnSizeClassName = this.props.size ? `btn-${this.props.size}` : 'btn-md';
    const addedClassNames = [
      this.state.isLiked ? 'active' : '',
      btnSizeClassName,
    ];
    const addedClassName = addedClassNames.join(' ');

    return (
      <button href="#" title="Like" onClick={this.handleClick}
          className={`btn-like btn btn-default btn-circle btn-outline ${addedClassName}`}>
        <i className="icon-like"></i>
      </button>
    );
  }
}

LikeButton.propTypes = {
  crowi: PropTypes.object.isRequired,
  pageId: PropTypes.string,
  isLiked: PropTypes.bool,
  size: PropTypes.string,
};