@material-ui/core/es/Breadcrumbs/Breadcrumbs.js

React components that implement Google's Material Design.

import _extends from "@babel/runtime/helpers/esm/extends";
import _objectWithoutPropertiesLoose from "@babel/runtime/helpers/esm/objectWithoutPropertiesLoose";
import React from 'react';
import warning from 'warning';
import PropTypes from 'prop-types';
import clsx from 'clsx';
import withStyles from '../styles/withStyles';
import Typography from '../Typography';
import BreadcrumbCollapsed from './BreadcrumbCollapsed';
import BreadcrumbSeparator from './BreadcrumbSeparator';
export const styles = {
  /* Styles applied to the root element. */
  root: {},

  /* Styles applied to the ol element. */
  ol: {
    display: 'flex',
    flexWrap: 'wrap',
    alignItems: 'center',
    padding: 0,
    // Reset
    margin: 0 // Reset

  },

  /* Styles applied to the li element. */
  li: {
    listStyle: 'none'
  },

  /* Styles applied to the separator element. */
  separator: {}
};

function insertSeparators(items, className, separator) {
  return items.reduce((acc, current, index) => {
    if (index < items.length - 1) {
      acc = acc.concat(current, React.createElement(BreadcrumbSeparator, {
        key: `separator-${index}`,
        className: className
      }, separator));
    } else {
      acc.push(current);
    }

    return acc;
  }, []);
}

const Breadcrumbs = React.forwardRef(function Breadcrumbs(props, ref) {
  const {
    children,
    classes,
    className,
    component: Component = 'nav',
    itemsAfterCollapse = 1,
    itemsBeforeCollapse = 1,
    maxItems = 8,
    separator = '/'
  } = props,
        other = _objectWithoutPropertiesLoose(props, ["children", "classes", "className", "component", "itemsAfterCollapse", "itemsBeforeCollapse", "maxItems", "separator"]);

  const [expanded, setExpanded] = React.useState(false);

  const renderItemsBeforeAndAfter = allItems => {
    const handleClickExpand = () => {
      setExpanded(true);
    }; // This defends against someone passing weird input, to ensure that if all
    // items would be shown anyway, we just show all items without the EllipsisItem


    if (itemsBeforeCollapse + itemsAfterCollapse >= allItems.length) {
      process.env.NODE_ENV !== "production" ? warning(false, ['Material-UI: you have provided an invalid combination of props to the Breadcrumbs.', `itemsAfterCollapse={${itemsAfterCollapse}} +itemsBeforeCollapse={${itemsBeforeCollapse}} >= maxItems={${maxItems}}`].join('\n')) : void 0;
      return allItems;
    }

    return [...allItems.slice(0, itemsBeforeCollapse), React.createElement(BreadcrumbCollapsed, {
      key: "ellipsis",
      onClick: handleClickExpand
    }), ...allItems.slice(allItems.length - itemsAfterCollapse, allItems.length)];
  };

  const allItems = React.Children.toArray(children).filter(child => React.isValidElement(child)).map((child, index) => React.createElement("li", {
    className: classes.li,
    key: `child-${index}`
  }, child));
  return React.createElement(Typography, _extends({
    ref: ref,
    component: Component,
    color: "textSecondary",
    className: clsx(classes.root, className)
  }, other), React.createElement("ol", {
    className: classes.ol
  }, insertSeparators(expanded || maxItems && allItems.length <= maxItems ? allItems : renderItemsBeforeAndAfter(allItems), classes.separator, separator)));
});
process.env.NODE_ENV !== "production" ? Breadcrumbs.propTypes = {
  /**
   * The breadcrumb children.
   */
  children: PropTypes.node.isRequired,

  /**
   * Override or extend the styles applied to the component.
   * See [CSS API](#css) below for more details.
   */
  classes: PropTypes.object.isRequired,

  /**
   * @ignore
   */
  className: PropTypes.string,

  /**
   * The component used for the root node.
   * Either a string to use a DOM element or a component.
   * By default, it maps the variant to a good default headline component.
   */
  component: PropTypes.elementType,

  /**
   * If max items is exceeded, the number of items to show after the ellipsis.
   */
  itemsAfterCollapse: PropTypes.number,

  /**
   * If max items is exceeded, the number of items to show before the ellipsis.
   */
  itemsBeforeCollapse: PropTypes.number,

  /**
   * Specifies the maximum number of breadcrumbs to display. When there are more
   * than the maximum number, only the first and last will be shown, with an
   * ellipsis in between.
   */
  maxItems: PropTypes.number,

  /**
   * Custom separator node.
   */
  separator: PropTypes.node
} : void 0;
export default withStyles(styles, {
  name: 'MuiBreadcrumbs'
})(Breadcrumbs);