react-instantsearch/packages/react-instantsearch-dom/src/components/RatingMenu.js

import React, { Component } from 'react';
import PropTypes from 'prop-types';
import classNames from 'classnames';
import { translatable } from 'react-instantsearch-core';
import { createClassNames, find, range } from '../core/utils';

const cx = createClassNames('RatingMenu');

class RatingMenu extends Component {
  static propTypes = {
    translate: PropTypes.func.isRequired,
    refine: PropTypes.func.isRequired,
    createURL: PropTypes.func.isRequired,
    min: PropTypes.number,
    max: PropTypes.number,
    currentRefinement: PropTypes.shape({
      min: PropTypes.number,
      max: PropTypes.number,
    }),
    count: PropTypes.arrayOf(
      PropTypes.shape({
        value: PropTypes.string,
        count: PropTypes.number,
      })
    ),
    canRefine: PropTypes.bool.isRequired,
    className: PropTypes.string,
  };

  static defaultProps = {
    className: '',
  };

  onClick(min, max, e) {
    e.preventDefault();
    e.stopPropagation();
    if (
      min === this.props.currentRefinement.min &&
      max === this.props.currentRefinement.max
    ) {
      this.props.refine({ min: this.props.min, max: this.props.max });
    } else {
      this.props.refine({ min, max });
    }
  }

  buildItem({
    max,
    lowerBound,
    count,
    translate,
    createURL,
    isLastSelectableItem,
  }) {
    const disabled = !count;
    const isCurrentMinLower = this.props.currentRefinement.min < lowerBound;
    const selected =
      (isLastSelectableItem && isCurrentMinLower) ||
      (!disabled &&
        lowerBound === this.props.currentRefinement.min &&
        max === this.props.currentRefinement.max);

    const icons = [];
    let rating = 0;
    for (let icon = 0; icon < max; icon++) {
      if (icon < lowerBound) {
        rating++;
      }
      icons.push([
        <svg
          key={icon}
          className={cx(
            'starIcon',
            icon >= lowerBound ? 'starIcon--empty' : 'starIcon--full'
          )}
          aria-hidden="true"
          width="24"
          height="24"
        >
          <use
            xlinkHref={`#${cx(
              icon >= lowerBound ? 'starEmptySymbol' : 'starSymbol'
            )}`}
          />
        </svg>,
        ' ',
      ]);
    }

    // The last item of the list (the default item), should not
    // be clickable if it is selected.
    const isLastAndSelect = isLastSelectableItem && selected;
    const onClickHandler =
      disabled || isLastAndSelect
        ? {}
        : {
            href: createURL({ min: lowerBound, max }),
            onClick: this.onClick.bind(this, lowerBound, max),
          };

    return (
      <li
        key={lowerBound}
        className={cx(
          'item',
          selected && 'item--selected',
          disabled && 'item--disabled'
        )}
      >
        <a
          className={cx('link')}
          aria-label={`${rating}${translate('ratingLabel')}`}
          {...onClickHandler}
        >
          {icons}
          <span className={cx('label')} aria-hidden="true">
            {translate('ratingLabel')}
          </span>{' '}
          <span className={cx('count')}>{count}</span>
        </a>
      </li>
    );
  }

  render() {
    const { min, max, translate, count, createURL, canRefine, className } =
      this.props;

    // min & max are always set when there is a results, otherwise it means
    // that we don't want to render anything since we don't have any values.
    const limitMin = min !== undefined && min >= 0 ? min : 1;
    const limitMax = max !== undefined && max >= 0 ? max : 0;
    const inclusiveLength = limitMax - limitMin + 1;

    const values = count
      .map((item) => ({ ...item, value: parseFloat(item.value) }))
      .filter((item) => item.value >= limitMin && item.value <= limitMax);

    const items = range({ start: 0, end: Math.max(inclusiveLength, 0) })
      .map((index) => {
        const element = find(values, (item) => item.value === limitMax - index);
        const placeholder = { value: limitMax - index, count: 0, total: 0 };

        return element || placeholder;
      })
      .reduce(
        (acc, item, index) =>
          acc.concat({
            ...item,
            total: index === 0 ? item.count : acc[index - 1].total + item.count,
          }),
        []
      )
      .map((item, index, arr) =>
        this.buildItem({
          lowerBound: item.value,
          count: item.total,
          isLastSelectableItem: arr.length - 1 === index,
          max: limitMax,
          translate,
          createURL,
        })
      );

    return (
      <div
        className={classNames(cx('', !canRefine && '-noRefinement'), className)}
      >
        <svg xmlns="http://www.w3.org/2000/svg" style={{ display: 'none' }}>
          <symbol id={cx('starSymbol')} viewBox="0 0 24 24">
            <path d="M12 .288l2.833 8.718h9.167l-7.417 5.389 2.833 8.718-7.416-5.388-7.417 5.388 2.833-8.718-7.416-5.389h9.167z" />
          </symbol>
          <symbol id={cx('starEmptySymbol')} viewBox="0 0 24 24">
            <path d="M12 6.76l1.379 4.246h4.465l-3.612 2.625 1.379 4.246-3.611-2.625-3.612 2.625 1.379-4.246-3.612-2.625h4.465l1.38-4.246zm0-6.472l-2.833 8.718h-9.167l7.416 5.389-2.833 8.718 7.417-5.388 7.416 5.388-2.833-8.718 7.417-5.389h-9.167l-2.833-8.718z" />
          </symbol>
        </svg>
        <ul className={cx('list', !canRefine && 'list--noRefinement')}>
          {items}
        </ul>
      </div>
    );
  }
}

export default translatable({
  ratingLabel: ' & Up',
})(RatingMenu);