SEO対策。microdataを付与したパンくずリストを生成する。HtmlHelper::addCrumbListを継承。

MyHtmlHelper.php

<?php
App::uses('HtmlHelper', 'View/Helper');

class MyHtmlHelper extends HtmlHelper {
	
	/**
	 * microdata属性対応版
	 * @link https://support.google.com/webmasters/answer/185417?hl=en
	 * @see HtmlHelper::getCrumbList()
	 */
	public function getCrumbList($options = array(), $startText = false) {
		$defaults = array('firstClass' => 'first', 'lastClass' => 'last', 'separator' => '', 'escape' => true);
		$options = (array)$options + $defaults;
		$firstClass = $options['firstClass'];
		$lastClass = $options['lastClass'];
		$separator = $options['separator'];
		$escape = $options['escape'];
		unset($options['firstClass'], $options['lastClass'], $options['separator'], $options['escape']);

		$crumbs = $this->_prepareCrumbs($startText, $escape);
		if (empty($crumbs)) {
			return null;
		}

		$result = '';
		$crumbCount = count($crumbs);
		$ulOptions = $options;
		$spanOptions = array('itemprop' => 'title', 'escape' => $escape);
		foreach ($crumbs as $which => $crumb) {
			$options = array();
			if (empty($crumb[1])) {
				$elementContent = $crumb[0];
			} else {
				$crumb[0] = $this->tag('span', $crumb[0], $spanOptions);
				$crumb[2]['itemprop'] = 'url';
				$crumb[2]['escape'] = false;
				$elementContent = $this->link($crumb[0], $crumb[1], $crumb[2]);
				$options['itemscope'] = '';
				$options['itemtype'] = 'http://data-vocabulary.org/Breadcrumb';
			}
			if (!$which && $firstClass !== false) {
				$options['class'] = $firstClass;
			} elseif ($which == $crumbCount - 1 && $lastClass !== false) {
				$options['class'] = $lastClass;
			}
			if (!empty($separator) && ($crumbCount - $which >= 2)) {
				$elementContent .= $separator;
			}
			$result .= $this->tag('li', $elementContent, $options);
		}
		return $this->tag('ul', $result, $ulOptions);
	}
}