reactstrap/src/Label.js

import React from 'react';
import PropTypes from 'prop-types';
import classNames from 'classnames';
import { mapToCssModules, tagPropType, isObject } from './utils';

const colWidths = ['xs', 'sm', 'md', 'lg', 'xl', 'xxl'];

const stringOrNumberProp = PropTypes.oneOfType([
  PropTypes.number,
  PropTypes.string,
]);

const columnProps = PropTypes.oneOfType([
  PropTypes.bool,
  PropTypes.string,
  PropTypes.number,
  PropTypes.shape({
    size: stringOrNumberProp,
    order: stringOrNumberProp,
    offset: stringOrNumberProp,
  }),
]);

const propTypes = {
  children: PropTypes.node,
  hidden: PropTypes.bool,
  check: PropTypes.bool,
  size: PropTypes.string,
  for: PropTypes.string,
  tag: tagPropType,
  className: PropTypes.string,
  cssModule: PropTypes.object,
  xs: columnProps,
  sm: columnProps,
  md: columnProps,
  lg: columnProps,
  xl: columnProps,
  xxl: columnProps,
  widths: PropTypes.array,
};

const getColumnSizeClass = (isXs, colWidth, colSize) => {
  if (colSize === true || colSize === '') {
    return isXs ? 'col' : `col-${colWidth}`;
  }
  if (colSize === 'auto') {
    return isXs ? 'col-auto' : `col-${colWidth}-auto`;
  }

  return isXs ? `col-${colSize}` : `col-${colWidth}-${colSize}`;
};

function Label(props) {
  const {
    className,
    cssModule,
    hidden,
    widths = colWidths,
    tag: Tag = 'label',
    check,
    size,
    for: htmlFor,
    ...attributes
  } = props;

  const colClasses = [];

  widths.forEach((colWidth, i) => {
    let columnProp = props[colWidth];

    delete attributes[colWidth];

    if (!columnProp && columnProp !== '') {
      return;
    }

    const isXs = !i;
    let colClass;

    if (isObject(columnProp)) {
      const colSizeInterfix = isXs ? '-' : `-${colWidth}-`;
      colClass = getColumnSizeClass(isXs, colWidth, columnProp.size);

      colClasses.push(
        mapToCssModules(
          classNames({
            [colClass]: columnProp.size || columnProp.size === '',
            [`order${colSizeInterfix}${columnProp.order}`]:
              columnProp.order || columnProp.order === 0,
            [`offset${colSizeInterfix}${columnProp.offset}`]:
              columnProp.offset || columnProp.offset === 0,
          }),
        ),
        cssModule,
      );
    } else {
      colClass = getColumnSizeClass(isXs, colWidth, columnProp);
      colClasses.push(colClass);
    }
  });

  const colFormLabel = size || colClasses.length;
  const formLabel = !(check || colFormLabel);

  const classes = mapToCssModules(
    classNames(
      className,
      hidden ? 'visually-hidden' : false,
      check ? 'form-check-label' : false,
      size ? `col-form-label-${size}` : false,
      colClasses,
      colFormLabel ? 'col-form-label' : false,
      formLabel ? 'form-label' : false,
    ),
    cssModule,
  );

  return <Tag htmlFor={htmlFor} {...attributes} className={classes} />;
}

Label.propTypes = propTypes;

export default Label;