3 * Taxonomy API: Core category-specific template tags
11 * Retrieve category link URL.
14 * @see get_term_link()
16 * @param int|object $category Category ID or object.
17 * @return string Link on success, empty string if category does not exist.
19 function get_category_link( $category ) {
20 if ( ! is_object( $category ) )
21 $category = (int) $category;
23 $category = get_term_link( $category, 'category' );
25 if ( is_wp_error( $category ) )
32 * Retrieve category parents with separator.
36 * @param int $id Category ID.
37 * @param bool $link Optional, default is false. Whether to format with link.
38 * @param string $separator Optional, default is '/'. How to separate categories.
39 * @param bool $nicename Optional, default is false. Whether to use nice name for display.
40 * @param array $visited Optional. Already linked to categories to prevent duplicates.
41 * @return string|WP_Error A list of category parents on success, WP_Error on failure.
43 function get_category_parents( $id, $link = false, $separator = '/', $nicename = false, $visited = array() ) {
45 $parent = get_term( $id, 'category' );
46 if ( is_wp_error( $parent ) )
50 $name = $parent->slug;
52 $name = $parent->name;
54 if ( $parent->parent && ( $parent->parent != $parent->term_id ) && !in_array( $parent->parent, $visited ) ) {
55 $visited[] = $parent->parent;
56 $chain .= get_category_parents( $parent->parent, $link, $separator, $nicename, $visited );
60 $chain .= '<a href="' . esc_url( get_category_link( $parent->term_id ) ) . '">'.$name.'</a>' . $separator;
62 $chain .= $name.$separator;
67 * Retrieve post categories.
69 * This tag may be used outside The Loop by passing a post id as the parameter.
71 * Note: This function only returns results from the default "category" taxonomy.
72 * For custom taxonomies use get_the_terms().
76 * @param int $id Optional, default to current post ID. The post ID.
77 * @return array Array of WP_Term objects, one for each category assigned to the post.
79 function get_the_category( $id = false ) {
80 $categories = get_the_terms( $id, 'category' );
81 if ( ! $categories || is_wp_error( $categories ) )
82 $categories = array();
84 $categories = array_values( $categories );
86 foreach ( array_keys( $categories ) as $key ) {
87 _make_cat_compat( $categories[$key] );
91 * Filters the array of categories to return for a post.
94 * @since 4.4.0 Added `$id` parameter.
96 * @param array $categories An array of categories to return for the post.
97 * @param int $id ID of the post.
99 return apply_filters( 'get_the_categories', $categories, $id );
103 * Sort categories by name.
105 * Used by usort() as a callback, should not be used directly. Can actually be
106 * used to sort any term object.
115 function _usort_terms_by_name( $a, $b ) {
116 return strcmp( $a->name, $b->name );
120 * Sort categories by ID.
122 * Used by usort() as a callback, should not be used directly. Can actually be
123 * used to sort any term object.
132 function _usort_terms_by_ID( $a, $b ) {
133 if ( $a->term_id > $b->term_id )
135 elseif ( $a->term_id < $b->term_id )
142 * Retrieve category name based on category ID.
146 * @param int $cat_ID Category ID.
147 * @return string|WP_Error Category name on success, WP_Error on failure.
149 function get_the_category_by_ID( $cat_ID ) {
150 $cat_ID = (int) $cat_ID;
151 $category = get_term( $cat_ID, 'category' );
153 if ( is_wp_error( $category ) )
156 return ( $category ) ? $category->name : '';
160 * Retrieve category list in either HTML list or custom format.
164 * @global WP_Rewrite $wp_rewrite
166 * @param string $separator Optional, default is empty string. Separator for between the categories.
167 * @param string $parents Optional. How to display the parents.
168 * @param int $post_id Optional. Post ID to retrieve categories.
171 function get_the_category_list( $separator = '', $parents='', $post_id = false ) {
173 if ( ! is_object_in_taxonomy( get_post_type( $post_id ), 'category' ) ) {
174 /** This filter is documented in wp-includes/category-template.php */
175 return apply_filters( 'the_category', '', $separator, $parents );
179 * Filters the categories before building the category list.
183 * @param array $categories An array of the post's categories.
184 * @param int|bool $post_id ID of the post we're retrieving categories for. When `false`, we assume the
185 * current post in the loop.
187 $categories = apply_filters( 'the_category_list', get_the_category( $post_id ), $post_id );
189 if ( empty( $categories ) ) {
190 /** This filter is documented in wp-includes/category-template.php */
191 return apply_filters( 'the_category', __( 'Uncategorized' ), $separator, $parents );
194 $rel = ( is_object( $wp_rewrite ) && $wp_rewrite->using_permalinks() ) ? 'rel="category tag"' : 'rel="category"';
197 if ( '' == $separator ) {
198 $thelist .= '<ul class="post-categories">';
199 foreach ( $categories as $category ) {
200 $thelist .= "\n\t<li>";
201 switch ( strtolower( $parents ) ) {
203 if ( $category->parent )
204 $thelist .= get_category_parents( $category->parent, true, $separator );
205 $thelist .= '<a href="' . esc_url( get_category_link( $category->term_id ) ) . '" ' . $rel . '>' . $category->name.'</a></li>';
208 $thelist .= '<a href="' . esc_url( get_category_link( $category->term_id ) ) . '" ' . $rel . '>';
209 if ( $category->parent )
210 $thelist .= get_category_parents( $category->parent, false, $separator );
211 $thelist .= $category->name.'</a></li>';
215 $thelist .= '<a href="' . esc_url( get_category_link( $category->term_id ) ) . '" ' . $rel . '>' . $category->name.'</a></li>';
221 foreach ( $categories as $category ) {
223 $thelist .= $separator;
224 switch ( strtolower( $parents ) ) {
226 if ( $category->parent )
227 $thelist .= get_category_parents( $category->parent, true, $separator );
228 $thelist .= '<a href="' . esc_url( get_category_link( $category->term_id ) ) . '" ' . $rel . '>' . $category->name.'</a>';
231 $thelist .= '<a href="' . esc_url( get_category_link( $category->term_id ) ) . '" ' . $rel . '>';
232 if ( $category->parent )
233 $thelist .= get_category_parents( $category->parent, false, $separator );
234 $thelist .= "$category->name</a>";
238 $thelist .= '<a href="' . esc_url( get_category_link( $category->term_id ) ) . '" ' . $rel . '>' . $category->name.'</a>';
245 * Filters the category or list of categories.
249 * @param array $thelist List of categories for the current post.
250 * @param string $separator Separator used between the categories.
251 * @param string $parents How to display the category parents. Accepts 'multiple',
252 * 'single', or empty.
254 return apply_filters( 'the_category', $thelist, $separator, $parents );
258 * Check if the current post in within any of the given categories.
260 * The given categories are checked against the post's categories' term_ids, names and slugs.
261 * Categories given as integers will only be checked against the post's categories' term_ids.
263 * Prior to v2.5 of WordPress, category names were not supported.
264 * Prior to v2.7, category slugs were not supported.
265 * Prior to v2.7, only one category could be compared: in_category( $single_category ).
266 * Prior to v2.7, this function could only be used in the WordPress Loop.
267 * As of 2.7, the function can be used anywhere if it is provided a post ID or post object.
271 * @param int|string|array $category Category ID, name or slug, or array of said.
272 * @param int|object $post Optional. Post to check instead of the current post. (since 2.7.0)
273 * @return bool True if the current post is in any of the given categories.
275 function in_category( $category, $post = null ) {
276 if ( empty( $category ) )
279 return has_category( $category, $post );
283 * Display the category list for the post.
287 * @param string $separator Optional, default is empty string. Separator for between the categories.
288 * @param string $parents Optional. How to display the parents.
289 * @param int $post_id Optional. Post ID to retrieve categories.
291 function the_category( $separator = '', $parents='', $post_id = false ) {
292 echo get_the_category_list( $separator, $parents, $post_id );
296 * Retrieve category description.
300 * @param int $category Optional. Category ID. Will use global category ID by default.
301 * @return string Category description, available.
303 function category_description( $category = 0 ) {
304 return term_description( $category, 'category' );
308 * Display or retrieve the HTML dropdown list of categories.
310 * The 'hierarchical' argument, which is disabled by default, will override the
311 * depth argument, unless it is true. When the argument is false, it will
312 * display all of the categories. When it is enabled it will use the value in
313 * the 'depth' argument.
316 * @since 4.2.0 Introduced the `value_field` argument.
317 * @since 4.6.0 Introduced the `required` argument.
319 * @param string|array $args {
320 * Optional. Array or string of arguments to generate a categories drop-down element.
322 * @type string $show_option_all Text to display for showing all categories. Default empty.
323 * @type string $show_option_none Text to display for showing no categories. Default empty.
324 * @type string $option_none_value Value to use when no category is selected. Default empty.
325 * @type string $orderby Which column to use for ordering categories. See get_terms() for a list
326 * of accepted values. Default 'id' (term_id).
327 * @type string $order Whether to order terms in ascending or descending order. Accepts 'ASC'
328 * or 'DESC'. Default 'ASC'.
329 * @type bool $pad_counts See get_terms() for an argument description. Default false.
330 * @type bool|int $show_count Whether to include post counts. Accepts 0, 1, or their bool equivalents.
332 * @type bool|int $hide_empty Whether to hide categories that don't have any posts. Accepts 0, 1, or
333 * their bool equivalents. Default 1.
334 * @type int $child_of Term ID to retrieve child terms of. See get_terms(). Default 0.
335 * @type array|string $exclude Array or comma/space-separated string of term ids to exclude.
336 * If `$include` is non-empty, `$exclude` is ignored. Default empty array.
337 * @type bool|int $echo Whether to echo or return the generated markup. Accepts 0, 1, or their
338 * bool equivalents. Default 1.
339 * @type bool|int $hierarchical Whether to traverse the taxonomy hierarchy. Accepts 0, 1, or their bool
340 * equivalents. Default 0.
341 * @type int $depth Maximum depth. Default 0.
342 * @type int $tab_index Tab index for the select element. Default 0 (no tabindex).
343 * @type string $name Value for the 'name' attribute of the select element. Default 'cat'.
344 * @type string $id Value for the 'id' attribute of the select element. Defaults to the value
346 * @type string $class Value for the 'class' attribute of the select element. Default 'postform'.
347 * @type int|string $selected Value of the option that should be selected. Default 0.
348 * @type string $value_field Term field that should be used to populate the 'value' attribute
349 * of the option elements. Accepts any valid term field: 'term_id', 'name',
350 * 'slug', 'term_group', 'term_taxonomy_id', 'taxonomy', 'description',
351 * 'parent', 'count'. Default 'term_id'.
352 * @type string|array $taxonomy Name of the category or categories to retrieve. Default 'category'.
353 * @type bool $hide_if_empty True to skip generating markup if no categories are found.
354 * Default false (create select element even if no categories are found).
355 * @type bool $required Whether the `<select>` element should have the HTML5 'required' attribute.
358 * @return string HTML content only if 'echo' argument is 0.
360 function wp_dropdown_categories( $args = '' ) {
362 'show_option_all' => '',
363 'show_option_none' => '',
375 'class' => 'postform',
378 'taxonomy' => 'category',
379 'hide_if_empty' => false,
380 'option_none_value' => -1,
381 'value_field' => 'term_id',
385 $defaults['selected'] = ( is_category() ) ? get_query_var( 'cat' ) : 0;
388 if ( isset( $args['type'] ) && 'link' == $args['type'] ) {
389 /* translators: 1: "type => link", 2: "taxonomy => link_category" alternative */
390 _deprecated_argument( __FUNCTION__, '3.0.0',
391 sprintf( __( '%1$s is deprecated. Use %2$s instead.' ),
392 '<code>type => link</code>',
393 '<code>taxonomy => link_category</code>'
396 $args['taxonomy'] = 'link_category';
399 $r = wp_parse_args( $args, $defaults );
400 $option_none_value = $r['option_none_value'];
402 if ( ! isset( $r['pad_counts'] ) && $r['show_count'] && $r['hierarchical'] ) {
403 $r['pad_counts'] = true;
406 $tab_index = $r['tab_index'];
408 $tab_index_attribute = '';
409 if ( (int) $tab_index > 0 ) {
410 $tab_index_attribute = " tabindex=\"$tab_index\"";
413 // Avoid clashes with the 'name' param of get_terms().
414 $get_terms_args = $r;
415 unset( $get_terms_args['name'] );
416 $categories = get_terms( $r['taxonomy'], $get_terms_args );
418 $name = esc_attr( $r['name'] );
419 $class = esc_attr( $r['class'] );
420 $id = $r['id'] ? esc_attr( $r['id'] ) : $name;
421 $required = $r['required'] ? 'required' : '';
423 if ( ! $r['hide_if_empty'] || ! empty( $categories ) ) {
424 $output = "<select $required name='$name' id='$id' class='$class' $tab_index_attribute>\n";
428 if ( empty( $categories ) && ! $r['hide_if_empty'] && ! empty( $r['show_option_none'] ) ) {
431 * Filters a taxonomy drop-down display element.
433 * A variety of taxonomy drop-down display elements can be modified
434 * just prior to display via this filter. Filterable arguments include
435 * 'show_option_none', 'show_option_all', and various forms of the
440 * @see wp_dropdown_categories()
442 * @param string $element Taxonomy element to list.
444 $show_option_none = apply_filters( 'list_cats', $r['show_option_none'] );
445 $output .= "\t<option value='" . esc_attr( $option_none_value ) . "' selected='selected'>$show_option_none</option>\n";
448 if ( ! empty( $categories ) ) {
450 if ( $r['show_option_all'] ) {
452 /** This filter is documented in wp-includes/category-template.php */
453 $show_option_all = apply_filters( 'list_cats', $r['show_option_all'] );
454 $selected = ( '0' === strval($r['selected']) ) ? " selected='selected'" : '';
455 $output .= "\t<option value='0'$selected>$show_option_all</option>\n";
458 if ( $r['show_option_none'] ) {
460 /** This filter is documented in wp-includes/category-template.php */
461 $show_option_none = apply_filters( 'list_cats', $r['show_option_none'] );
462 $selected = selected( $option_none_value, $r['selected'], false );
463 $output .= "\t<option value='" . esc_attr( $option_none_value ) . "'$selected>$show_option_none</option>\n";
466 if ( $r['hierarchical'] ) {
467 $depth = $r['depth']; // Walk the full depth.
469 $depth = -1; // Flat.
471 $output .= walk_category_dropdown_tree( $categories, $depth, $r );
474 if ( ! $r['hide_if_empty'] || ! empty( $categories ) ) {
475 $output .= "</select>\n";
478 * Filters the taxonomy drop-down output.
482 * @param string $output HTML output.
483 * @param array $r Arguments used to build the drop-down.
485 $output = apply_filters( 'wp_dropdown_cats', $output, $r );
494 * Display or retrieve the HTML list of categories.
497 * @since 4.4.0 Introduced the `hide_title_if_empty` and `separator` arguments. The `current_category` argument was modified to
498 * optionally accept an array of values.
500 * @param string|array $args {
501 * Array of optional arguments.
503 * @type int $child_of Term ID to retrieve child terms of. See get_terms(). Default 0.
504 * @type int|array $current_category ID of category, or array of IDs of categories, that should get the
505 * 'current-cat' class. Default 0.
506 * @type int $depth Category depth. Used for tab indentation. Default 0.
507 * @type bool|int $echo True to echo markup, false to return it. Default 1.
508 * @type array|string $exclude Array or comma/space-separated string of term IDs to exclude.
509 * If `$hierarchical` is true, descendants of `$exclude` terms will also
510 * be excluded; see `$exclude_tree`. See get_terms().
511 * Default empty string.
512 * @type array|string $exclude_tree Array or comma/space-separated string of term IDs to exclude, along
513 * with their descendants. See get_terms(). Default empty string.
514 * @type string $feed Text to use for the feed link. Default 'Feed for all posts filed
516 * @type string $feed_image URL of an image to use for the feed link. Default empty string.
517 * @type string $feed_type Feed type. Used to build feed link. See get_term_feed_link().
518 * Default empty string (default feed).
519 * @type bool|int $hide_empty Whether to hide categories that don't have any posts attached to them.
521 * @type bool $hide_title_if_empty Whether to hide the `$title_li` element if there are no terms in
522 * the list. Default false (title will always be shown).
523 * @type bool $hierarchical Whether to include terms that have non-empty descendants.
524 * See get_terms(). Default true.
525 * @type string $order Which direction to order categories. Accepts 'ASC' or 'DESC'.
527 * @type string $orderby The column to use for ordering categories. Default 'ID'.
528 * @type string $separator Separator between links. Default '<br />'.
529 * @type bool|int $show_count Whether to show how many posts are in the category. Default 0.
530 * @type string $show_option_all Text to display for showing all categories. Default empty string.
531 * @type string $show_option_none Text to display for the 'no categories' option.
532 * Default 'No categories'.
533 * @type string $style The style used to display the categories list. If 'list', categories
534 * will be output as an unordered list. If left empty or another value,
535 * categories will be output separated by `<br>` tags. Default 'list'.
536 * @type string $taxonomy Taxonomy name. Default 'category'.
537 * @type string $title_li Text to use for the list title `<li>` element. Pass an empty string
538 * to disable. Default 'Categories'.
539 * @type bool|int $use_desc_for_title Whether to use the category description as the title attribute.
542 * @return false|string HTML content only if 'echo' argument is 0.
544 function wp_list_categories( $args = '' ) {
547 'current_category' => 0,
551 'exclude_tree' => '',
556 'hide_title_if_empty' => false,
557 'hierarchical' => true,
560 'separator' => '<br />',
562 'show_option_all' => '',
563 'show_option_none' => __( 'No categories' ),
565 'taxonomy' => 'category',
566 'title_li' => __( 'Categories' ),
567 'use_desc_for_title' => 1,
570 $r = wp_parse_args( $args, $defaults );
572 if ( !isset( $r['pad_counts'] ) && $r['show_count'] && $r['hierarchical'] )
573 $r['pad_counts'] = true;
575 // Descendants of exclusions should be excluded too.
576 if ( true == $r['hierarchical'] ) {
577 $exclude_tree = array();
579 if ( $r['exclude_tree'] ) {
580 $exclude_tree = array_merge( $exclude_tree, wp_parse_id_list( $r['exclude_tree'] ) );
583 if ( $r['exclude'] ) {
584 $exclude_tree = array_merge( $exclude_tree, wp_parse_id_list( $r['exclude'] ) );
587 $r['exclude_tree'] = $exclude_tree;
591 if ( ! isset( $r['class'] ) )
592 $r['class'] = ( 'category' == $r['taxonomy'] ) ? 'categories' : $r['taxonomy'];
594 if ( ! taxonomy_exists( $r['taxonomy'] ) ) {
598 $show_option_all = $r['show_option_all'];
599 $show_option_none = $r['show_option_none'];
601 $categories = get_categories( $r );
604 if ( $r['title_li'] && 'list' == $r['style'] && ( ! empty( $categories ) || ! $r['hide_title_if_empty'] ) ) {
605 $output = '<li class="' . esc_attr( $r['class'] ) . '">' . $r['title_li'] . '<ul>';
607 if ( empty( $categories ) ) {
608 if ( ! empty( $show_option_none ) ) {
609 if ( 'list' == $r['style'] ) {
610 $output .= '<li class="cat-item-none">' . $show_option_none . '</li>';
612 $output .= $show_option_none;
616 if ( ! empty( $show_option_all ) ) {
620 // For taxonomies that belong only to custom post types, point to a valid archive.
621 $taxonomy_object = get_taxonomy( $r['taxonomy'] );
622 if ( ! in_array( 'post', $taxonomy_object->object_type ) && ! in_array( 'page', $taxonomy_object->object_type ) ) {
623 foreach ( $taxonomy_object->object_type as $object_type ) {
624 $_object_type = get_post_type_object( $object_type );
626 // Grab the first one.
627 if ( ! empty( $_object_type->has_archive ) ) {
628 $posts_page = get_post_type_archive_link( $object_type );
634 // Fallback for the 'All' link is the posts page.
635 if ( ! $posts_page ) {
636 if ( 'page' == get_option( 'show_on_front' ) && get_option( 'page_for_posts' ) ) {
637 $posts_page = get_permalink( get_option( 'page_for_posts' ) );
639 $posts_page = home_url( '/' );
643 $posts_page = esc_url( $posts_page );
644 if ( 'list' == $r['style'] ) {
645 $output .= "<li class='cat-item-all'><a href='$posts_page'>$show_option_all</a></li>";
647 $output .= "<a href='$posts_page'>$show_option_all</a>";
651 if ( empty( $r['current_category'] ) && ( is_category() || is_tax() || is_tag() ) ) {
652 $current_term_object = get_queried_object();
653 if ( $current_term_object && $r['taxonomy'] === $current_term_object->taxonomy ) {
654 $r['current_category'] = get_queried_object_id();
658 if ( $r['hierarchical'] ) {
659 $depth = $r['depth'];
661 $depth = -1; // Flat.
663 $output .= walk_category_tree( $categories, $depth, $r );
666 if ( $r['title_li'] && 'list' == $r['style'] )
667 $output .= '</ul></li>';
670 * Filters the HTML output of a taxonomy list.
674 * @param string $output HTML output.
675 * @param array $args An array of taxonomy-listing arguments.
677 $html = apply_filters( 'wp_list_categories', $output, $args );
689 * The text size is set by the 'smallest' and 'largest' arguments, which will
690 * use the 'unit' argument value for the CSS text size unit. The 'format'
691 * argument can be 'flat' (default), 'list', or 'array'. The flat value for the
692 * 'format' argument will separate tags with spaces. The list value for the
693 * 'format' argument will format the tags in a UL HTML list. The array value for
694 * the 'format' argument will return in PHP array type format.
696 * The 'orderby' argument will accept 'name' or 'count' and defaults to 'name'.
697 * The 'order' is the direction to sort, defaults to 'ASC' and can be 'DESC'.
699 * The 'number' argument is how many tags to return. By default, the limit will
700 * be to return the top 45 tags in the tag cloud list.
702 * The 'topic_count_text' argument is a nooped plural from _n_noop() to generate the
703 * text for the tooltip of the tag link.
705 * The 'topic_count_text_callback' argument is a function, which given the count
706 * of the posts with that tag returns a text for the tooltip of the tag link.
708 * The 'post_type' argument is used only when 'link' is set to 'edit'. It determines the post_type
709 * passed to edit.php for the popular tags edit links.
711 * The 'exclude' and 'include' arguments are used for the get_tags() function. Only one
712 * should be used, because only one will be used and the other ignored, if they are both set.
716 * @param array|string|null $args Optional. Override default arguments.
717 * @return void|array Generated tag cloud, only if no failures and 'array' is set for the 'format' argument.
718 * Otherwise, this function outputs the tag cloud.
720 function wp_tag_cloud( $args = '' ) {
722 'smallest' => 8, 'largest' => 22, 'unit' => 'pt', 'number' => 45,
723 'format' => 'flat', 'separator' => "\n", 'orderby' => 'name', 'order' => 'ASC',
724 'exclude' => '', 'include' => '', 'link' => 'view', 'taxonomy' => 'post_tag', 'post_type' => '', 'echo' => true
726 $args = wp_parse_args( $args, $defaults );
728 $tags = get_terms( $args['taxonomy'], array_merge( $args, array( 'orderby' => 'count', 'order' => 'DESC' ) ) ); // Always query top tags
730 if ( empty( $tags ) || is_wp_error( $tags ) )
733 foreach ( $tags as $key => $tag ) {
734 if ( 'edit' == $args['link'] )
735 $link = get_edit_term_link( $tag->term_id, $tag->taxonomy, $args['post_type'] );
737 $link = get_term_link( intval($tag->term_id), $tag->taxonomy );
738 if ( is_wp_error( $link ) )
741 $tags[ $key ]->link = $link;
742 $tags[ $key ]->id = $tag->term_id;
745 $return = wp_generate_tag_cloud( $tags, $args ); // Here's where those top tags get sorted according to $args
748 * Filters the tag cloud output.
752 * @param string $return HTML output of the tag cloud.
753 * @param array $args An array of tag cloud arguments.
755 $return = apply_filters( 'wp_tag_cloud', $return, $args );
757 if ( 'array' == $args['format'] || empty($args['echo']) )
764 * Default topic count scaling for tag links
766 * @param int $count number of posts with that tag
767 * @return int scaled count
769 function default_topic_count_scale( $count ) {
770 return round(log10($count + 1) * 100);
774 * Generates a tag cloud (heatmap) from provided data.
776 * @todo Complete functionality.
779 * @param array $tags List of tags.
780 * @param string|array $args {
781 * Optional. Array of string of arguments for generating a tag cloud.
783 * @type int $smallest Smallest font size used to display tags. Paired
784 * with the value of `$unit`, to determine CSS text
785 * size unit. Default 8 (pt).
786 * @type int $largest Largest font size used to display tags. Paired
787 * with the value of `$unit`, to determine CSS text
788 * size unit. Default 22 (pt).
789 * @type string $unit CSS text size unit to use with the `$smallest`
790 * and `$largest` values. Accepts any valid CSS text
791 * size unit. Default 'pt'.
792 * @type int $number The number of tags to return. Accepts any
793 * positive integer or zero to return all.
795 * @type string $format Format to display the tag cloud in. Accepts 'flat'
796 * (tags separated with spaces), 'list' (tags displayed
797 * in an unordered list), or 'array' (returns an array).
799 * @type string $separator HTML or text to separate the tags. Default "\n" (newline).
800 * @type string $orderby Value to order tags by. Accepts 'name' or 'count'.
801 * Default 'name'. The {@see 'tag_cloud_sort'} filter
802 * can also affect how tags are sorted.
803 * @type string $order How to order the tags. Accepts 'ASC' (ascending),
804 * 'DESC' (descending), or 'RAND' (random). Default 'ASC'.
805 * @type int|bool $filter Whether to enable filtering of the final output
806 * via {@see 'wp_generate_tag_cloud'}. Default 1|true.
807 * @type string $topic_count_text Nooped plural text from _n_noop() to supply to
808 * tag tooltips. Default null.
809 * @type callable $topic_count_text_callback Callback used to generate nooped plural text for
810 * tag tooltips based on the count. Default null.
811 * @type callable $topic_count_scale_callback Callback used to determine the tag count scaling
812 * value. Default default_topic_count_scale().
814 * @return string|array Tag cloud as a string or an array, depending on 'format' argument.
816 function wp_generate_tag_cloud( $tags, $args = '' ) {
818 'smallest' => 8, 'largest' => 22, 'unit' => 'pt', 'number' => 0,
819 'format' => 'flat', 'separator' => "\n", 'orderby' => 'name', 'order' => 'ASC',
820 'topic_count_text' => null, 'topic_count_text_callback' => null,
821 'topic_count_scale_callback' => 'default_topic_count_scale', 'filter' => 1,
824 $args = wp_parse_args( $args, $defaults );
826 $return = ( 'array' === $args['format'] ) ? array() : '';
828 if ( empty( $tags ) ) {
832 // Juggle topic count tooltips:
833 if ( isset( $args['topic_count_text'] ) ) {
834 // First look for nooped plural support via topic_count_text.
835 $translate_nooped_plural = $args['topic_count_text'];
836 } elseif ( ! empty( $args['topic_count_text_callback'] ) ) {
837 // Look for the alternative callback style. Ignore the previous default.
838 if ( $args['topic_count_text_callback'] === 'default_topic_count_text' ) {
839 $translate_nooped_plural = _n_noop( '%s topic', '%s topics' );
841 $translate_nooped_plural = false;
843 } elseif ( isset( $args['single_text'] ) && isset( $args['multiple_text'] ) ) {
844 // If no callback exists, look for the old-style single_text and multiple_text arguments.
845 $translate_nooped_plural = _n_noop( $args['single_text'], $args['multiple_text'] );
847 // This is the default for when no callback, plural, or argument is passed in.
848 $translate_nooped_plural = _n_noop( '%s topic', '%s topics' );
852 * Filters how the items in a tag cloud are sorted.
856 * @param array $tags Ordered array of terms.
857 * @param array $args An array of tag cloud arguments.
859 $tags_sorted = apply_filters( 'tag_cloud_sort', $tags, $args );
860 if ( empty( $tags_sorted ) ) {
864 if ( $tags_sorted !== $tags ) {
865 $tags = $tags_sorted;
866 unset( $tags_sorted );
868 if ( 'RAND' === $args['order'] ) {
871 // SQL cannot save you; this is a second (potentially different) sort on a subset of data.
872 if ( 'name' === $args['orderby'] ) {
873 uasort( $tags, '_wp_object_name_sort_cb' );
875 uasort( $tags, '_wp_object_count_sort_cb' );
878 if ( 'DESC' === $args['order'] ) {
879 $tags = array_reverse( $tags, true );
884 if ( $args['number'] > 0 )
885 $tags = array_slice( $tags, 0, $args['number'] );
888 $real_counts = array(); // For the alt tag
889 foreach ( (array) $tags as $key => $tag ) {
890 $real_counts[ $key ] = $tag->count;
891 $counts[ $key ] = call_user_func( $args['topic_count_scale_callback'], $tag->count );
894 $min_count = min( $counts );
895 $spread = max( $counts ) - $min_count;
898 $font_spread = $args['largest'] - $args['smallest'];
899 if ( $font_spread < 0 )
901 $font_step = $font_spread / $spread;
903 // Assemble the data that will be used to generate the tag cloud markup.
904 $tags_data = array();
905 foreach ( $tags as $key => $tag ) {
906 $tag_id = isset( $tag->id ) ? $tag->id : $key;
908 $count = $counts[ $key ];
909 $real_count = $real_counts[ $key ];
911 if ( $translate_nooped_plural ) {
912 $title = sprintf( translate_nooped_plural( $translate_nooped_plural, $real_count ), number_format_i18n( $real_count ) );
914 $title = call_user_func( $args['topic_count_text_callback'], $real_count, $tag, $args );
917 $tags_data[] = array(
919 'url' => '#' != $tag->link ? $tag->link : '#',
920 'name' => $tag->name,
922 'slug' => $tag->slug,
923 'real_count' => $real_count,
924 'class' => 'tag-link-' . $tag_id,
925 'font_size' => $args['smallest'] + ( $count - $min_count ) * $font_step,
930 * Filters the data used to generate the tag cloud.
934 * @param array $tags_data An array of term data for term used to generate the tag cloud.
936 $tags_data = apply_filters( 'wp_generate_tag_cloud_data', $tags_data );
940 // generate the output links array
941 foreach ( $tags_data as $key => $tag_data ) {
942 $class = $tag_data['class'] . ' tag-link-position-' . ( $key + 1 );
943 $a[] = "<a href='" . esc_url( $tag_data['url'] ) . "' class='" . esc_attr( $class ) . "' title='" . esc_attr( $tag_data['title'] ) . "' style='font-size: " . esc_attr( str_replace( ',', '.', $tag_data['font_size'] ) . $args['unit'] ) . ";'>" . esc_html( $tag_data['name'] ) . "</a>";
946 switch ( $args['format'] ) {
951 $return = "<ul class='wp-tag-cloud'>\n\t<li>";
952 $return .= join( "</li>\n\t<li>", $a );
953 $return .= "</li>\n</ul>\n";
956 $return = join( $args['separator'], $a );
960 if ( $args['filter'] ) {
962 * Filters the generated output of a tag cloud.
964 * The filter is only evaluated if a true value is passed
965 * to the $filter argument in wp_generate_tag_cloud().
969 * @see wp_generate_tag_cloud()
971 * @param array|string $return String containing the generated HTML tag cloud output
972 * or an array of tag links if the 'format' argument
974 * @param array $tags An array of terms used in the tag cloud.
975 * @param array $args An array of wp_generate_tag_cloud() arguments.
977 return apply_filters( 'wp_generate_tag_cloud', $return, $tags, $args );
985 * Serves as a callback for comparing objects based on name.
987 * Used with `uasort()`.
992 * @param object $a The first object to compare.
993 * @param object $b The second object to compare.
994 * @return int Negative number if `$a->name` is less than `$b->name`, zero if they are equal,
995 * or greater than zero if `$a->name` is greater than `$b->name`.
997 function _wp_object_name_sort_cb( $a, $b ) {
998 return strnatcasecmp( $a->name, $b->name );
1002 * Serves as a callback for comparing objects based on count.
1004 * Used with `uasort()`.
1009 * @param object $a The first object to compare.
1010 * @param object $b The second object to compare.
1011 * @return bool Whether the count value for `$a` is greater than the count value for `$b`.
1013 function _wp_object_count_sort_cb( $a, $b ) {
1014 return ( $a->count > $b->count );
1022 * Retrieve HTML list content for category list.
1024 * @uses Walker_Category to create HTML list content.
1026 * @see Walker_Category::walk() for parameters and return description.
1029 function walk_category_tree() {
1030 $args = func_get_args();
1031 // the user's options are the third parameter
1032 if ( empty( $args[2]['walker'] ) || ! ( $args[2]['walker'] instanceof Walker ) ) {
1033 $walker = new Walker_Category;
1035 $walker = $args[2]['walker'];
1037 return call_user_func_array( array( $walker, 'walk' ), $args );
1041 * Retrieve HTML dropdown (select) content for category list.
1043 * @uses Walker_CategoryDropdown to create HTML dropdown content.
1045 * @see Walker_CategoryDropdown::walk() for parameters and return description.
1048 function walk_category_dropdown_tree() {
1049 $args = func_get_args();
1050 // the user's options are the third parameter
1051 if ( empty( $args[2]['walker'] ) || ! ( $args[2]['walker'] instanceof Walker ) ) {
1052 $walker = new Walker_CategoryDropdown;
1054 $walker = $args[2]['walker'];
1056 return call_user_func_array( array( $walker, 'walk' ), $args );
1064 * Retrieve the link to the tag.
1067 * @see get_term_link()
1069 * @param int|object $tag Tag ID or object.
1070 * @return string Link on success, empty string if tag does not exist.
1072 function get_tag_link( $tag ) {
1073 if ( ! is_object( $tag ) )
1076 $tag = get_term_link( $tag, 'post_tag' );
1078 if ( is_wp_error( $tag ) )
1085 * Retrieve the tags for a post.
1089 * @param int $id Post ID.
1090 * @return array|false|WP_Error Array of tag objects on success, false on failure.
1092 function get_the_tags( $id = 0 ) {
1095 * Filters the array of tags for the given post.
1099 * @see get_the_terms()
1101 * @param array $terms An array of tags for the given post.
1103 return apply_filters( 'get_the_tags', get_the_terms( $id, 'post_tag' ) );
1107 * Retrieve the tags for a post formatted as a string.
1111 * @param string $before Optional. Before tags.
1112 * @param string $sep Optional. Between tags.
1113 * @param string $after Optional. After tags.
1114 * @param int $id Optional. Post ID. Defaults to the current post.
1115 * @return string|false|WP_Error A list of tags on success, false if there are no terms, WP_Error on failure.
1117 function get_the_tag_list( $before = '', $sep = '', $after = '', $id = 0 ) {
1120 * Filters the tags list for a given post.
1124 * @param string $tag_list List of tags.
1125 * @param string $before String to use before tags.
1126 * @param string $sep String to use between the tags.
1127 * @param string $after String to use after tags.
1128 * @param int $id Post ID.
1130 return apply_filters( 'the_tags', get_the_term_list( $id, 'post_tag', $before, $sep, $after ), $before, $sep, $after, $id );
1134 * Retrieve the tags for a post.
1138 * @param string $before Optional. Before list.
1139 * @param string $sep Optional. Separate items using this.
1140 * @param string $after Optional. After list.
1142 function the_tags( $before = null, $sep = ', ', $after = '' ) {
1143 if ( null === $before )
1144 $before = __('Tags: ');
1145 echo get_the_tag_list($before, $sep, $after);
1149 * Retrieve tag description.
1153 * @param int $tag Optional. Tag ID. Will use global tag ID by default.
1154 * @return string Tag description, available.
1156 function tag_description( $tag = 0 ) {
1157 return term_description( $tag );
1161 * Retrieve term description.
1165 * @param int $term Optional. Term ID. Will use global term ID by default.
1166 * @param string $taxonomy Optional taxonomy name. Defaults to 'post_tag'.
1167 * @return string Term description, available.
1169 function term_description( $term = 0, $taxonomy = 'post_tag' ) {
1170 if ( ! $term && ( is_tax() || is_tag() || is_category() ) ) {
1171 $term = get_queried_object();
1173 $taxonomy = $term->taxonomy;
1174 $term = $term->term_id;
1177 $description = get_term_field( 'description', $term, $taxonomy );
1178 return is_wp_error( $description ) ? '' : $description;
1182 * Retrieve the terms of the taxonomy that are attached to the post.
1186 * @param int|object $post Post ID or object.
1187 * @param string $taxonomy Taxonomy name.
1188 * @return array|false|WP_Error Array of WP_Term objects on success, false if there are no terms
1189 * or the post does not exist, WP_Error on failure.
1191 function get_the_terms( $post, $taxonomy ) {
1192 if ( ! $post = get_post( $post ) )
1195 $terms = get_object_term_cache( $post->ID, $taxonomy );
1196 if ( false === $terms ) {
1197 $terms = wp_get_object_terms( $post->ID, $taxonomy );
1198 if ( ! is_wp_error( $terms ) ) {
1199 $term_ids = wp_list_pluck( $terms, 'term_id' );
1200 wp_cache_add( $post->ID, $term_ids, $taxonomy . '_relationships' );
1205 * Filters the list of terms attached to the given post.
1209 * @param array|WP_Error $terms List of attached terms, or WP_Error on failure.
1210 * @param int $post_id Post ID.
1211 * @param string $taxonomy Name of the taxonomy.
1213 $terms = apply_filters( 'get_the_terms', $terms, $post->ID, $taxonomy );
1215 if ( empty( $terms ) )
1222 * Retrieve a post's terms as a list with specified format.
1226 * @param int $id Post ID.
1227 * @param string $taxonomy Taxonomy name.
1228 * @param string $before Optional. Before list.
1229 * @param string $sep Optional. Separate items using this.
1230 * @param string $after Optional. After list.
1231 * @return string|false|WP_Error A list of terms on success, false if there are no terms, WP_Error on failure.
1233 function get_the_term_list( $id, $taxonomy, $before = '', $sep = '', $after = '' ) {
1234 $terms = get_the_terms( $id, $taxonomy );
1236 if ( is_wp_error( $terms ) )
1239 if ( empty( $terms ) )
1244 foreach ( $terms as $term ) {
1245 $link = get_term_link( $term, $taxonomy );
1246 if ( is_wp_error( $link ) ) {
1249 $links[] = '<a href="' . esc_url( $link ) . '" rel="tag">' . $term->name . '</a>';
1253 * Filters the term links for a given taxonomy.
1255 * The dynamic portion of the filter name, `$taxonomy`, refers
1256 * to the taxonomy slug.
1260 * @param array $links An array of term links.
1262 $term_links = apply_filters( "term_links-$taxonomy", $links );
1264 return $before . join( $sep, $term_links ) . $after;
1268 * Display the terms in a list.
1272 * @param int $id Post ID.
1273 * @param string $taxonomy Taxonomy name.
1274 * @param string $before Optional. Before list.
1275 * @param string $sep Optional. Separate items using this.
1276 * @param string $after Optional. After list.
1277 * @return false|void False on WordPress error.
1279 function the_terms( $id, $taxonomy, $before = '', $sep = ', ', $after = '' ) {
1280 $term_list = get_the_term_list( $id, $taxonomy, $before, $sep, $after );
1282 if ( is_wp_error( $term_list ) )
1286 * Filters the list of terms to display.
1290 * @param array $term_list List of terms to display.
1291 * @param string $taxonomy The taxonomy name.
1292 * @param string $before String to use before the terms.
1293 * @param string $sep String to use between the terms.
1294 * @param string $after String to use after the terms.
1296 echo apply_filters( 'the_terms', $term_list, $taxonomy, $before, $sep, $after );
1300 * Check if the current post has any of given category.
1304 * @param string|int|array $category Optional. The category name/term_id/slug or array of them to check for.
1305 * @param int|object $post Optional. Post to check instead of the current post.
1306 * @return bool True if the current post has any of the given categories (or any category, if no category specified).
1308 function has_category( $category = '', $post = null ) {
1309 return has_term( $category, 'category', $post );
1313 * Check if the current post has any of given tags.
1315 * The given tags are checked against the post's tags' term_ids, names and slugs.
1316 * Tags given as integers will only be checked against the post's tags' term_ids.
1317 * If no tags are given, determines if post has any tags.
1319 * Prior to v2.7 of WordPress, tags given as integers would also be checked against the post's tags' names and slugs (in addition to term_ids)
1320 * Prior to v2.7, this function could only be used in the WordPress Loop.
1321 * As of 2.7, the function can be used anywhere if it is provided a post ID or post object.
1325 * @param string|int|array $tag Optional. The tag name/term_id/slug or array of them to check for.
1326 * @param int|object $post Optional. Post to check instead of the current post. (since 2.7.0)
1327 * @return bool True if the current post has any of the given tags (or any tag, if no tag specified).
1329 function has_tag( $tag = '', $post = null ) {
1330 return has_term( $tag, 'post_tag', $post );
1334 * Check if the current post has any of given terms.
1336 * The given terms are checked against the post's terms' term_ids, names and slugs.
1337 * Terms given as integers will only be checked against the post's terms' term_ids.
1338 * If no terms are given, determines if post has any terms.
1342 * @param string|int|array $term Optional. The term name/term_id/slug or array of them to check for.
1343 * @param string $taxonomy Taxonomy name
1344 * @param int|object $post Optional. Post to check instead of the current post.
1345 * @return bool True if the current post has any of the given tags (or any tag, if no tag specified).
1347 function has_term( $term = '', $taxonomy = '', $post = null ) {
1348 $post = get_post($post);
1353 $r = is_object_in_term( $post->ID, $taxonomy, $term );
1354 if ( is_wp_error( $r ) )