Breadcrumb Navigation für WordPress

<?php
/**
 * Klasse zum Erstellen einer WordPress Breadcrumb Navigation.
 *
 * @author Dominik Schilling
 * @license GPLv2
 * @link https://dominikschilling.de/204/
 *
 * @version 0.1.1
 */
class DS_WP_Breadcrumb {
	/**
	 * The list of breadcrumb items.
	 *
	 * @var array
	 * @since 1.0.0
	 */
	public $breadcrumb;

	/**
	 * Templates for link, current/standard state and before/after.
	 *
	 * @var array
	 */
	public $templates;

	/**
	 * Various strings.
	 *
	 * @var array
	 */
	public $strings;

	/**
	 * Various options.
	 *
	 * @var array
	 * @access public
	 */
	public $options;

	/**
	 * Constructor.
	 *
	 * @param array $templates An array with templates for link, current/standard state and before/after.
	 * @param array $options An array with options.
	 * @param array $strings An array with strings.
	 * @param bool $autorun Autorun or not.
	 * @return string
	 */
	public function __construct( $templates = array(), $options = array(), $strings = array(), $autorun = true ) {
		$this->templates = wp_parse_args(
			$templates,
			array(
				'link' => '<a href="%s">%s</a>',
				'current' => '<span class="c">%s</span>',
				'standard' => '<span class="s">%s</span>',
				'before' => '<nav>',
				'after' => '</nav>'
			)
		);
		$this->options = wp_parse_args( $options, array(
			'separator' => ' › ',
			'posts_on_front' => 'posts' == get_option( 'show_on_front' ) ? true : false,
			'page_for_posts' => get_option( 'page_for_posts' ),
			'show_pagenum' => true, // support pagination
			'show_htfpt' => false // show hierarchical terms for post types
		) );
		$this->strings = wp_parse_args( $strings, array(
			'home' => 'Startseite',
			'search' => array(
				'singular' => 'Ein Suchergebnis zu <em>%s</em>',
				'plural'   => '%s Suchergebnisse zu <em>%s</em>'
			),
			'paged' => 'Seite %d',
			'404_error' => 'Fehler: Seite existiert nicht'
		) );

		// Generate breadcrumb
		if ( $autorun)
			echo $this->output();
	}

	/**
	 * Return the final breadcrumb.
	 *
	 * @return string
	 */
	public function output() {
		if ( empty( $this->breadcrumb ) )
			$this->generate();

		$breadcrumb = (string) implode( $this->options['separator'], $this->breadcrumb );

		return $this->templates['before'] . $breadcrumb . $this->templates['after'];
	}

	/**
	 * Build the item based on the type.
	 *
	 * @param string|array $item
	 * @param string $type
	 * @return string
	 */
	protected function template( $item, $type = 'standard' ) {
		if ( is_array( $item ) )
			$type = 'link';

		switch ( $type ) {
			case'link':
				return $this->template(
					sprintf(
						$this->templates['link'],
						esc_url( $item['link'] ),
						$item['title']
					)
				);
				break;
			case 'current':
				return sprintf( $this->templates['current'], $item );
				break;
			case 'standard':
				return sprintf( $this->templates['standard'], $item );
				break;
		}
	}

	/**
	 * Helper to generate taxonomy parents.
	 *
	 * @param mixed $term_id
	 * @param mixed $taxonomy
	 * @return void
	 */
	protected function generate_tax_parents( $term_id, $taxonomy ) {
		$parent_ids = array_reverse( get_ancestors( $term_id, $taxonomy ) );

		foreach ( $parent_ids as $parent_id ) {
			$term = get_term( $parent_id, $taxonomy );
			$this->breadcrumb["archive_{$taxonomy}_{$parent_id}"] = $this->template( array(
				'link' => get_term_link( $term->slug, $taxonomy ),
				'title' => $term->name
			) );
		}
	}

	/**
	 * Generate the breadcrumb.
	 *
	 * @return void
	 */
	public function generate() {
		$post_type = get_post_type();
		$queried_object = get_queried_object();
		$this->options['show_pagenum'] = ( $this->options['show_pagenum'] && is_paged() ) ? true : false;


		// Home & Front Page
		$this->breadcrumb['home'] = $this->template( $this->strings['home'], 'current' );
		$home_linked = $this->template( array(
			'link' => home_url( '/' ),
			'title' => $this->strings['home']
		) );


		if ( $this->options['posts_on_front'] ) {
			if ( ! is_home() || $this->options['show_pagenum'] )
				$this->breadcrumb['home'] = $home_linked;
		} else {
			if ( ! is_front_page() )
				$this->breadcrumb['home'] = $home_linked;

			if ( is_home() && !$this->options['show_pagenum'] )
				$this->breadcrumb['blog'] = $this->template( get_the_title( $this->options['page_for_posts'] ), 'current' );

			if ( ( 'post' == $post_type && ! is_search() && ! is_home() ) || ( 'post' == $post_type && $this->options['show_pagenum'] ) )
				$this->breadcrumb['blog'] = $this->template( array(
					'link' => get_permalink( $this->options['page_for_posts'] ),
					'title' => get_the_title( $this->options['page_for_posts'] )
				) );
		}

		// Post Type Archive as index
		if ( is_singular() || ( is_archive() && ! is_post_type_archive() ) || is_search() || $this->options['show_pagenum'] ) {
			if ( $post_type_link = get_post_type_archive_link( $post_type ) ) {
				$post_type_label = get_post_type_object( $post_type )->labels->name;
				$this->breadcrumb["archive_{$post_type}"] = $this->template(
					array(
					'link' => $post_type_link,
					'title' => $post_type_label
				) );
			}
		}

		if ( is_singular() ) { // Posts, (Sub)Pages, Attachments and Custom Post Types
			if ( ! is_front_page() ) {
				if ( $this->options['show_htfpt'] ) {
					$_id = $queried_object->ID;
					$_post_type = $post_type;

					if ( is_attachment() ) {
						// Show terms of the parent page
						$_id = $queried_object->post_parent;
						$_post_type = get_post_type( $_id );
					}

					$taxonomies = get_object_taxonomies( $_post_type, 'objects' );
					$taxonomies = array_values( wp_list_filter( $taxonomies, array(
						'hierarchical' => true
					) ) );

					if ( ! empty( $taxonomies ) ) {
						$taxonomy = $taxonomies[0]->name; // Get the first taxonomy
						$terms = get_the_terms( $_id, $taxonomy );

						if ( ! empty( $terms ) ) {
							$terms = array_values( $terms );
							$term = $terms[0]; // Get the first term

							if ( 0 != $term->parent )
								$this->generate_tax_parents( $term->term_id, $taxonomy );

							$this->breadcrumb["archive_{$taxonomy}"] = $this->template( array(
								'link' => get_term_link( $term->slug, $taxonomy ),
								'title' => $term->name
							) );
						}
					}
				}

				if ( 0 != $queried_object->post_parent ) { // Get Parents
					$parents = array_reverse( get_post_ancestors( $queried_object->ID ) );

					foreach ( $parents as $parent ) {
						$this->breadcrumb["archive_{$post_type}_{$parent}"] = $this->template( array(
							'link' => get_permalink( $parent ),
							'title' => get_the_title( $parent )
						) );
					}
				}


				$this->breadcrumb["single_{$post_type}"] = $this->template( get_the_title(), 'current' );
			}
		} elseif ( is_search() ) { // Search
			$total = $GLOBALS['wp_query']->found_posts;
			$text = sprintf(
				_n(
					$this->strings['search']['singular'],
					$this->strings['search']['plural'],
					$total
				),
				$total,
				get_search_query()
			);

			$this->breadcrumb['search'] = $this->template( $text, 'current' );

			if ( $this->options['show_pagenum'] )
				$this->breadcrumb['search'] = $this->template( array(
					'link' => home_url( '?s=' . urlencode( get_search_query( false ) ) ),
					'title' => $text
				) );
		} elseif ( is_archive() ) { // All archive pages
			if ( is_category() || is_tag() || is_tax() ) { // Categories, Tags and Custom Taxonomies
				$taxonomy = $queried_object->taxonomy;

				if ( 0 != $queried_object->parent && is_taxonomy_hierarchical( $taxonomy ) ) // Get Parents
					$this->generate_tax_parents( $queried_object->term_id, $taxonomy );

				$this->breadcrumb["archive_{$taxonomy}"] = $this->template( $queried_object->name, 'current' );

				if ( $this->options['show_pagenum'] )
					$this->breadcrumb["archive_{$taxonomy}"] = $this->template( array(
						'link' => get_term_link( $queried_object->slug, $taxonomy ),
						'title' => $queried_object->name
					) );

			} elseif ( is_date() ) { // Date archive
				if ( is_year() ) { // Year archive
					$this->breadcrumb['archive_year'] = $this->template( get_the_date( 'Y' ), 'current' );

					if ( $this->options['show_pagenum'] )
						$this->breadcrumb['archive_year'] = $this->template( array(
							'link' => get_year_link( get_query_var( 'year' ) ),
							'title' => get_the_date( 'Y' )
						) );
				} elseif ( is_month() ) { // Month archive
					$this->breadcrumb['archive_year'] = $this->template( array(
						'link' => get_year_link( get_query_var( 'year' ) ),
						'title' => get_the_date( 'Y' )
					) );
					$this->breadcrumb['archive_month'] = $this->template( get_the_date( 'F' ), 'current' );

					if ( $this->options['show_pagenum'] )
						$this->breadcrumb['archive_month'] = $this->template( array(
							'link' => get_month_link( get_query_var( 'year' ), get_query_var( 'monthnum' ) ),
							'title' => get_the_date( 'F' )
						) );
				} elseif ( is_day() ) { // Day archive
					$this->breadcrumb['archive_year'] = $this->template( array(
						'link' => get_year_link( get_query_var( 'year' ) ),
						'title' => get_the_date( 'Y' )
					) );
					$this->breadcrumb['archive_month'] = $this->template( array(
						'link' => get_month_link( get_query_var( 'year' ), get_query_var( 'monthnum' ) ),
						'title' => get_the_date( 'F' )
					) );
					$this->breadcrumb['archive_day'] = $this->template( get_the_date( 'j' ) );

					if ( $this->options['show_pagenum'] )
						$this->breadcrumb['archive_day'] = $this->template( array(
							'link' => get_month_link(
								get_query_var( 'year' ),
								get_query_var( 'monthnum' ),
								get_query_var( 'day' )
							),
							'title' => get_the_date( 'F' )
						) );
				}
			} elseif ( is_post_type_archive() && ! is_paged() ) { // Custom Post Type Archive
				$post_type_label = get_post_type_object( $post_type )->labels->name;
				$this->breadcrumb["archive_{$post_type}"] = $this->template( $post_type_label, 'current' );
			} elseif ( is_author() ) { // Author archive
				$this->breadcrumb['archive_author'] = $this->template( $queried_object->display_name, 'current' );
			}
		} elseif ( is_404() ) {
			$this->breadcrumb['404'] = $this->template( $this->strings['404_error'], 'current' );
		}

		if ( $this->options['show_pagenum'] )
			$this->breadcrumb['paged'] = $this->template(
				sprintf(
					$this->strings['paged'],
					get_query_var( 'paged' )
				),
				'current'
			);
	}
}
?>