[wpkama embed] https://wp-kama.ru/541 Breadcrumbs for WordPress

Kama_Breadcrumbs.php

<?php

/**
 * Breadcrumbs for WordPress
 *
 * @param string $sep   Separator. Default is ' » '.
 * @param array  $l10n  For localization. See the variable `$default_l10n`.
 * @param array  $args  Options. See the variable `$def_args`.
 *
 * @return void Outputs HTML code to the screen
 *
 * version 3.3.3
 */
function kama_breadcrumbs( $sep = ' » ', $l10n = [], $args = [] ) {
	$kb = new Kama_Breadcrumbs;
	echo $kb->get_crumbs( $sep, $l10n, $args );
}

class Kama_Breadcrumbs {

	public $arg;

	// Localisation
	static $l10n = [
		'home'       => 'Главная',
		'paged'      => 'Страница %d',
		'_404'       => 'Ошибка 404',
		'search'     => 'Результаты поиска по запросу - <b>%s</b>',
		'author'     => 'Архив автора: <b>%s</b>',
		'year'       => 'Архив за <b>%d</b> год',
		'month'      => 'Архив за: <b>%s</b>',
		'day'        => '',
		'attachment' => 'Медиа: %s',
		'tag'        => 'Записи по метке: <b>%s</b>',
		'tax_tag'    => '%1$s из "%2$s" по тегу: <b>%3$s</b>',
		// tax_tag will output: 'post_type from "taxonomy_name" by tag: term_name'.
		// If separate placeholders are needed, for example, only the term name, write like this: 'posts by tag: %3$s'
	];

	// Default parameters
	static $args = [
		// Display breadcrumbs on the front page
		'on_front_page'   => true,
		// Show the post title at the end (last element). For posts, pages, attachments
		'show_post_title' => true,
		// Show the taxonomy item title at the end (last element). For tags, categories, and other taxonomies
		'show_term_title' => true,
		// Template for the last title. If enabled: show_post_title or show_term_title
		'title_patt'      => '<span class="kb_title">%s</span>',
		// Show the last separator when the title at the end is not displayed
		'last_sep'        => true,
		// 'markup' - microdata. Can be: 'rdf.data-vocabulary.org', 'schema.org', '' - without microdata
		// Or you can specify your own markup array:
		// array( 'wrappatt'=>'<div class="kama_breadcrumbs">%s</div>', 'linkpatt'=>'<a href="%s">%s</a>', 'sep_after'=>'', )
		'markup'          => 'schema.org',
		// Priority taxonomies, needed when a post is in multiple taxonomies
		'priority_tax'    => [ 'category' ],
		// 'priority_terms' - priority items of taxonomies when a post is in multiple items of the same taxonomy at the same time.
		// For example: array( 'category'=>array(45,'term_name'), 'tax_name'=>array(1,2,'name') )
		// 'category' - taxonomy for which priority items are specified: 45 - term ID and 'term_name' - label.
		// The order of 45 and 'term_name' matters: the earlier, the more important. All specified terms are more important than unspecified ones...
		'priority_terms'  => [],
		// Add rel=nofollow to links?
		'nofollow'        => false,

		// Service
		'sep'             => '',
		'linkpatt'        => '',
		'pg_end'          => '',
	];

	function get_crumbs( $sep, $l10n, $args ) {
		global $post, $wp_post_types;

		self::$args['sep'] = $sep;

		// Filters the defaults and merges
		$loc = (object) array_merge( apply_filters( 'kama_breadcrumbs_default_loc', self::$l10n ), $l10n );
		$arg = (object) array_merge( apply_filters( 'kama_breadcrumbs_default_args', self::$args ), $args );

		$arg->sep = '<span class="kb_sep">' . $arg->sep . '</span>'; // supplement

		// simplify
		$sep = &$arg->sep;
		$this->arg = &$arg;

		// micro-markup ---
		if( 1 ){
			$mark = &$arg->markup;

			// Default markup
			if( ! $mark ){
				$mark = [
					'wrappatt'  => '<div class="kama_breadcrumbs">%s</div>',
					'linkpatt'  => '<a href="%s">%s</a>',
					'sep_after' => '',
				];
			}
			// rdf
			elseif( $mark === 'rdf.data-vocabulary.org' ){
				$mark = [
					'wrappatt'  => '<div class="kama_breadcrumbs" prefix="v: http://rdf.data-vocabulary.org/#">%s</div>',
					'linkpatt'  => '<span typeof="v:Breadcrumb"><a href="%s" rel="v:url" property="v:title">%s</a>',
					'sep_after' => '</span>', // close span after the separator!
				];
			}
			// schema.org
			elseif( $mark === 'schema.org' ){
				$mark = [
					'wrappatt'  => '<div class="kama_breadcrumbs" itemscope itemtype="http://schema.org/BreadcrumbList">%s</div>',
					'linkpatt'  => '<span itemprop="itemListElement" itemscope itemtype="http://schema.org/ListItem"><a href="%s" itemprop="item"><span itemprop="name">%s</span></a></span>',
					'sep_after' => '',
				];
			}

			elseif( ! is_array( $mark ) ){
				die( __CLASS__ . ': "markup" parameter must be array...' );
			}

			$wrappatt = $mark['wrappatt'];
			$arg->linkpatt = $arg->nofollow ? str_replace( '<a ', '<a rel="nofollow"', $mark['linkpatt'] ) : $mark['linkpatt'];
			$arg->sep .= $mark['sep_after'] . "\n";
		}

		$linkpatt = $arg->linkpatt; // simplify

		$q_obj = get_queried_object();

		// maybe it's an empty archive of the tax
		$ptype = null;
		if( ! $post ){
			if( isset( $q_obj->taxonomy ) ){
				$ptype = $wp_post_types[ get_taxonomy( $q_obj->taxonomy )->object_type[0] ];
			}
		}
		else{
			$ptype = $wp_post_types[ $post->post_type ];
		}

		// paged
		$arg->pg_end = '';
		$paged_num = get_query_var( 'paged' ) ?: get_query_var( 'page' );
		if( $paged_num ){
			$arg->pg_end = $sep . sprintf( $loc->paged, (int) $paged_num );
		}

		$pg_end = $arg->pg_end; // simplify

		$out = '';

		if( is_front_page() ){
			return $arg->on_front_page ? sprintf( $wrappatt, ( $paged_num ? sprintf( $linkpatt, get_home_url(), $loc->home ) . $pg_end : $loc->home ) ) : '';
		}
		// post page when a separate page is set for the main page.
		elseif( is_home() ){
			$out = $paged_num ? ( sprintf( $linkpatt, get_permalink( $q_obj ), esc_html( $q_obj->post_title ) ) . $pg_end ) : esc_html( $q_obj->post_title );
		}
		elseif( is_404() ){
			$out = $loc->_404;
		}
		elseif( is_search() ){
			$out = sprintf( $loc->search, esc_html( $GLOBALS['s'] ) );
		}
		elseif( is_author() ){
			$tit = sprintf( $loc->author, esc_html( $q_obj->display_name ) );
			$out = ( $paged_num ? sprintf( $linkpatt, get_author_posts_url( $q_obj->ID, $q_obj->user_nicename ) . $pg_end, $tit ) : $tit );
		}
		elseif( is_year() || is_month() || is_day() ){
			$y_url = get_year_link( $year = get_the_time( 'Y' ) );

			if( is_year() ){
				$tit = sprintf( $loc->year, $year );
				$out = ( $paged_num ? sprintf( $linkpatt, $y_url, $tit ) . $pg_end : $tit );
			}
			// month day
			else{
				$y_link = sprintf( $linkpatt, $y_url, $year );
				$m_url = get_month_link( $year, get_the_time( 'm' ) );

				if( is_month() ){
					$tit = sprintf( $loc->month, get_the_time( 'F' ) );
					$out = $y_link . $sep . ( $paged_num ? sprintf( $linkpatt, $m_url, $tit ) . $pg_end : $tit );
				}
				elseif( is_day() ){
					$m_link = sprintf( $linkpatt, $m_url, get_the_time( 'F' ) );
					$out = $y_link . $sep . $m_link . $sep . get_the_time( 'l' );
				}
			}
		}
		// Hierarchical posts
		elseif( is_singular() && $ptype->hierarchical ){
			$out = $this->_add_title( $this->_page_crumbs( $post ), $post );
		}
		// Taxonomies, flat posts, and attachments
		else{
			$term = $q_obj; // taxonomies

			// define a term for posts (including attachments)
			if( is_singular() ){
				// modify $post to define the term for the parent of the attachment
				if( is_attachment() && $post->post_parent ){
					$save_post = $post; // сохраним
					$post = get_post( $post->post_parent );
				}

				// takes into account if attachments are attached to hierarchical taxonomies - it happens :)
				$taxonomies = get_object_taxonomies( $post->post_type );
				// let's leave only hierarchical and public, just in case....
				$taxonomies = array_intersect( $taxonomies, get_taxonomies( [
					'hierarchical' => true,
					'public'       => true,
				] ) );

				if( $taxonomies ){
					// sort by priority
					if( ! empty( $arg->priority_tax ) ){

						usort( $taxonomies, static function( $a, $b ) use ( $arg ) {
							$a_index = array_search( $a, $arg->priority_tax );
							if( $a_index === false ){
								$a_index = 9999999;
							}

							$b_index = array_search( $b, $arg->priority_tax );
							if( $b_index === false ){
								$b_index = 9999999;
							}

							return ( $b_index === $a_index ) ? 0 : ( $b_index < $a_index ? 1 : -1 ); // меньше индекс - выше
						} );
					}

					// try to get the terms, in order of tax priority
					foreach( $taxonomies as $taxname ){

						if( $terms = get_the_terms( $post->ID, $taxname ) ){
							// проверим приоритетные термины для таксы
							$prior_terms = &$arg->priority_terms[ $taxname ];

							if( $prior_terms && count( $terms ) > 2 ){

								foreach( (array) $prior_terms as $term_id ){
									$filter_field = is_numeric( $term_id ) ? 'term_id' : 'slug';
									$_terms = wp_list_filter( $terms, [ $filter_field => $term_id ] );

									if( $_terms ){
										$term = array_shift( $_terms );
										break;
									}
								}
							}
							else{
								$term = array_shift( $terms );
							}

							break;
						}
					}
				}

				// revert back (for attachments)
				if( isset( $save_post ) ){
					$post = $save_post;
				}
			}

			// output

			// terms or post of any type with terms
			if( $term && isset( $term->term_id ) ){
				$term = apply_filters( 'kama_breadcrumbs_term', $term );

				// attachment
				if( is_attachment() ){
					if( ! $post->post_parent ){
						$out = sprintf( $loc->attachment, esc_html( $post->post_title ) );
					}
					else{
						if( ! $out = apply_filters( 'attachment_tax_crumbs', '', $term, $this ) ){
							$_crumbs = $this->_tax_crumbs( $term, 'self' );
							$parent_tit = sprintf( $linkpatt, get_permalink( $post->post_parent ), get_the_title( $post->post_parent ) );
							$_out = implode( $sep, [ $_crumbs, $parent_tit ] );
							$out = $this->_add_title( $_out, $post );
						}
					}
				}
				// single
				elseif( is_single() ){
					if( ! $out = apply_filters( 'post_tax_crumbs', '', $term, $this ) ){
						$_crumbs = $this->_tax_crumbs( $term, 'self' );
						$out = $this->_add_title( $_crumbs, $post );
					}
				}
				// non-hierarchical taxonomy (tags)
				elseif( ! is_taxonomy_hierarchical( $term->taxonomy ) ){
					// метка
					if( is_tag() ){
						$out = $this->_add_title( '', $term, sprintf( $loc->tag, esc_html( $term->name ) ) );
					}
					// taxonomy
					elseif( is_tax() ){
						$post_label = $ptype->labels->name;
						$tax_label = $GLOBALS['wp_taxonomies'][ $term->taxonomy ]->labels->name;
						$out = $this->_add_title( '', $term, sprintf( $loc->tax_tag, $post_label, $tax_label, esc_html( $term->name ) ) );
					}
				}
				// hierarchical taxonomy (category)
				elseif( ! $out = apply_filters( 'term_tax_crumbs', '', $term, $this ) ){
					$_crumbs = $this->_tax_crumbs( $term, 'parent' );
					$out = $this->_add_title( $_crumbs, $term, esc_html( $term->name ) );
				}
			}
			// attachments (of post) without terms
			elseif( is_attachment() ){
				$parent = get_post( $post->post_parent );
				$parent_link = sprintf( $linkpatt, get_permalink( $parent ), esc_html( $parent->post_title ) );
				$_out = $parent_link;

				// attachment of post with hierarchical type
				if( is_post_type_hierarchical( $parent->post_type ) ){
					$parent_crumbs = $this->_page_crumbs( $parent );
					$_out = implode( $sep, [ $parent_crumbs, $parent_link ] );
				}

				$out = $this->_add_title( $_out, $post );
			}
			// posts without terms
			elseif( is_singular() ){
				$out = $this->_add_title( '', $post );
			}
		}

		// replacement of link to post type archive page
		$home_after = apply_filters( 'kama_breadcrumbs_home_after', '', $linkpatt, $sep, $ptype );

		if( '' === $home_after ){
			// A link to the archive page of a post type for:
			// individual pages of that type; archives of that type; taxonomies associated with that type.
			if( $ptype && $ptype->has_archive && ! in_array( $ptype->name, [ 'post', 'page', 'attachment' ] )
			    && ( is_post_type_archive() || is_singular() || ( is_tax() && in_array( $term->taxonomy, $ptype->taxonomies ) ) )
			){
				$pt_title = $ptype->labels->name;

				// first page of the post type archive
				if( is_post_type_archive() && ! $paged_num ){
					$home_after = sprintf( $this->arg->title_patt, $pt_title );
				}
				// singular, paged post_type_archive, tax
				else{
					$home_after = sprintf( $linkpatt, get_post_type_archive_link( $ptype->name ), $pt_title );

					$home_after .= ( ( $paged_num && ! is_tax() ) ? $pg_end : $sep ); // pagination
				}
			}
		}

		$before_out = sprintf( $linkpatt, home_url(), $loc->home ) . ( $home_after ? $sep . $home_after : ( $out ? $sep : '' ) );

		$out = apply_filters( 'kama_breadcrumbs_pre_out', $out, $sep, $loc, $arg );

		$out = sprintf( $wrappatt, $before_out . $out );

		return apply_filters( 'kama_breadcrumbs', $out, $sep, $loc, $arg );
	}

	function _page_crumbs( $post ) {
		$parent = $post->post_parent;

		$crumbs = [];
		while( $parent ){
			$page = get_post( $parent );
			$crumbs[] = sprintf( $this->arg->linkpatt, get_permalink( $page ), esc_html( $page->post_title ) );
			$parent = $page->post_parent;
		}

		return implode( $this->arg->sep, array_reverse( $crumbs ) );
	}

	function _tax_crumbs( $term, $start_from = 'self' ) {
		$termlinks = [];
		$term_id = ( $start_from === 'parent' ) ? $term->parent : $term->term_id;
		while( $term_id ){
			$term = get_term( $term_id, $term->taxonomy );
			$termlinks[] = sprintf( $this->arg->linkpatt, get_term_link( $term ), esc_html( $term->name ) );
			$term_id = $term->parent;
		}

		if( $termlinks ){
			return implode( $this->arg->sep, array_reverse( $termlinks ) );
		}

		return '';
	}

	/**
	 * Adds a title to the passed text, taking into account all options.
	 * Adds a delimiter at the beginning, if necessary.
	 *
	 * @param string $add_to
	 * @param object $obj
	 * @param string $term_title
	 *
	 * @return string
	 */
	function _add_title( $add_to, $obj, $term_title = '' ) {

		// simplify.
		$arg = & $this->arg;

		// $term_title is cleaned separately, HTML tags can be inside.
		$title = $term_title ?: esc_html( $obj->post_title );
		$show_title = $term_title ? $arg->show_term_title : $arg->show_post_title;

		// pagination
		if( $arg->pg_end ){
			$link = $term_title ? get_term_link( $obj ) : get_permalink( $obj );
			$add_to .= ( $add_to ? $arg->sep : '' ) . sprintf( $arg->linkpatt, $link, $title ) . $arg->pg_end;
		}
		// add sep
		elseif( $add_to ){
			if( $show_title ){
				$add_to .= $arg->sep . sprintf( $arg->title_patt, $title );
			}
			elseif( $arg->last_sep ){
				$add_to .= $arg->sep;
			}
		}
		// sep will be later...
		elseif( $show_title ){
			$add_to = sprintf( $arg->title_patt, $title );
		}

		return $add_to;
	}

}

/**
 * Changelog:
 * 3.3 - new hooks: attachment_tax_crumbs, post_tax_crumbs, term_tax_crumbs. Allow to extend taxonomy breadcrumbs.
 * 3.2 - fixed an issue with the separator when 'show_term_title' is disabled. Stabilized the logic.
 * 3.1 - fixed an issue with esc_html() for term titles - it was rendering tags incorrectly...
 * 3.0 - Wrapped in a class. Added options: 'title_patt', 'last_sep'. Refactored the code. Added pagination for posts.
 * 2.5 - ADD: 'show_term_title' option
 * 2.4 - Minor code adjustments
 * 2.3 - ADD: Posts page when a separate page is set for the homepage.
 * 2.2 - ADD: Link to post type archive on taxonomies page
 * 2.1 - ADD: $sep, $loc, $args params to hooks
 * 2.0 - ADD: fourth argument $ptype to the 'kama_breadcrumbs_home_after' filter
 * 1.9 - ADD: 'kama_breadcrumbs_default_loc' filter to change the default localization
 * 1.8 - FIX: notes when there are no posts in the category
 * 1.7 - Improved handling of primary taxonomies.
 */