3 * WordPress Category API
9 * Retrieve list of category objects.
11 * If you change the type to 'link' in the arguments, then the link categories
12 * will be returned instead. Also all categories will be updated to be backwards
13 * compatible with pre-2.3 plugins and themes.
16 * @see get_terms() Type of arguments that can be changed.
17 * @link http://codex.wordpress.org/Function_Reference/get_categories
19 * @param string|array $args Optional. Change the defaults retrieving categories.
20 * @return array List of categories.
22 function get_categories( $args = '' ) {
23 $defaults = array( 'taxonomy' => 'category' );
24 $args = wp_parse_args( $args, $defaults );
26 $taxonomy = $args['taxonomy'];
29 * Filter the taxonomy used to retrieve terms when calling {@see get_categories()}.
33 * @param string $taxonomy Taxonomy to retrieve terms from.
34 * @param array $args An array of arguments. See {@see get_terms()}.
36 $taxonomy = apply_filters( 'get_categories_taxonomy', $taxonomy, $args );
39 if ( isset($args['type']) && 'link' == $args['type'] ) {
40 _deprecated_argument( __FUNCTION__, '3.0', '' );
41 $taxonomy = $args['taxonomy'] = 'link_category';
44 $categories = (array) get_terms( $taxonomy, $args );
46 foreach ( array_keys( $categories ) as $k )
47 _make_cat_compat( $categories[$k] );
53 * Retrieves category data given a category ID or category object.
55 * If you pass the $category parameter an object, which is assumed to be the
56 * category row object retrieved the database. It will cache the category data.
58 * If you pass $category an integer of the category ID, then that category will
59 * be retrieved from the database, if it isn't already cached, and pass it back.
61 * If you look at get_term(), then both types will be passed through several
62 * filters and finally sanitized based on the $filter parameter value.
64 * The category will converted to maintain backwards compatibility.
68 * @param int|object $category Category ID or Category row object
69 * @param string $output Optional. Constant OBJECT, ARRAY_A, or ARRAY_N
70 * @param string $filter Optional. Default is raw or no WordPress defined filter will applied.
71 * @return object|array|WP_Error|null Category data in type defined by $output parameter. WP_Error if $category is empty, null if it does not exist.
73 function get_category( $category, $output = OBJECT, $filter = 'raw' ) {
74 $category = get_term( $category, 'category', $output, $filter );
76 if ( is_wp_error( $category ) )
79 _make_cat_compat( $category );
85 * Retrieve category based on URL containing the category slug.
87 * Breaks the $category_path parameter up to get the category slug.
89 * Tries to find the child path and will return it. If it doesn't find a
90 * match, then it will return the first category matching slug, if $full_match,
91 * is set to false. If it does not, then it will return null.
93 * It is also possible that it will return a WP_Error object on failure. Check
94 * for it when using this function.
98 * @param string $category_path URL containing category slugs.
99 * @param bool $full_match Optional. Whether full path should be matched.
100 * @param string $output Optional. Constant OBJECT, ARRAY_A, or ARRAY_N
101 * @return null|object|array Null on failure. Type is based on $output value.
103 function get_category_by_path( $category_path, $full_match = true, $output = OBJECT ) {
104 $category_path = rawurlencode( urldecode( $category_path ) );
105 $category_path = str_replace( '%2F', '/', $category_path );
106 $category_path = str_replace( '%20', ' ', $category_path );
107 $category_paths = '/' . trim( $category_path, '/' );
108 $leaf_path = sanitize_title( basename( $category_paths ) );
109 $category_paths = explode( '/', $category_paths );
111 foreach ( (array) $category_paths as $pathdir )
112 $full_path .= ( $pathdir != '' ? '/' : '' ) . sanitize_title( $pathdir );
114 $categories = get_terms( 'category', array('get' => 'all', 'slug' => $leaf_path) );
116 if ( empty( $categories ) )
119 foreach ( $categories as $category ) {
120 $path = '/' . $leaf_path;
121 $curcategory = $category;
122 while ( ( $curcategory->parent != 0 ) && ( $curcategory->parent != $curcategory->term_id ) ) {
123 $curcategory = get_term( $curcategory->parent, 'category' );
124 if ( is_wp_error( $curcategory ) )
126 $path = '/' . $curcategory->slug . $path;
129 if ( $path == $full_path ) {
130 $category = get_term( $category->term_id, 'category', $output );
131 _make_cat_compat( $category );
136 // If full matching is not required, return the first cat that matches the leaf.
137 if ( ! $full_match ) {
138 $category = get_term( reset( $categories )->term_id, 'category', $output );
139 _make_cat_compat( $category );
147 * Retrieve category object by category slug.
151 * @param string $slug The category slug.
152 * @return object Category data object
154 function get_category_by_slug( $slug ) {
155 $category = get_term_by( 'slug', $slug, 'category' );
157 _make_cat_compat( $category );
163 * Retrieve the ID of a category from its name.
167 * @param string $cat_name Category name.
168 * @return int 0, if failure and ID of category on success.
170 function get_cat_ID( $cat_name ) {
171 $cat = get_term_by( 'name', $cat_name, 'category' );
173 return $cat->term_id;
178 * Retrieve the name of a category from its ID.
182 * @param int $cat_id Category ID
183 * @return string Category name, or an empty string if category doesn't exist.
185 function get_cat_name( $cat_id ) {
186 $cat_id = (int) $cat_id;
187 $category = get_term( $cat_id, 'category' );
188 if ( ! $category || is_wp_error( $category ) )
190 return $category->name;
194 * Check if a category is an ancestor of another category.
196 * You can use either an id or the category object for both parameters. If you
197 * use an integer the category will be retrieved.
201 * @param int|object $cat1 ID or object to check if this is the parent category.
202 * @param int|object $cat2 The child category.
203 * @return bool Whether $cat2 is child of $cat1
205 function cat_is_ancestor_of( $cat1, $cat2 ) {
206 return term_is_ancestor_of( $cat1, $cat2, 'category' );
210 * Sanitizes category data based on context.
214 * @param object|array $category Category data
215 * @param string $context Optional. Default is 'display'.
216 * @return object|array Same type as $category with sanitized data for safe use.
218 function sanitize_category( $category, $context = 'display' ) {
219 return sanitize_term( $category, 'category', $context );
223 * Sanitizes data in single category key field.
227 * @param string $field Category key to sanitize
228 * @param mixed $value Category value to sanitize
229 * @param int $cat_id Category ID
230 * @param string $context What filter to use, 'raw', 'display', etc.
231 * @return mixed Same type as $value after $value has been sanitized.
233 function sanitize_category_field( $field, $value, $cat_id, $context ) {
234 return sanitize_term_field( $field, $value, $cat_id, 'category', $context );
240 * Retrieves all post tags.
243 * @see get_terms() For list of arguments to pass.
245 * @param string|array $args Tag arguments to use when retrieving tags.
246 * @return array List of tags.
248 function get_tags( $args = '' ) {
249 $tags = get_terms( 'post_tag', $args );
251 if ( empty( $tags ) ) {
257 * Filter the array of term objects returned for the 'post_tag' taxonomy.
261 * @param array $tags Array of 'post_tag' term objects.
262 * @param array $args An array of arguments. @see get_terms()
264 $tags = apply_filters( 'get_tags', $tags, $args );
269 * Retrieve post tag by tag ID or tag object.
271 * If you pass the $tag parameter an object, which is assumed to be the tag row
272 * object retrieved the database. It will cache the tag data.
274 * If you pass $tag an integer of the tag ID, then that tag will
275 * be retrieved from the database, if it isn't already cached, and pass it back.
277 * If you look at get_term(), then both types will be passed through several
278 * filters and finally sanitized based on the $filter parameter value.
282 * @param int|object $tag
283 * @param string $output Optional. Constant OBJECT, ARRAY_A, or ARRAY_N
284 * @param string $filter Optional. Default is raw or no WordPress defined filter will applied.
285 * @return object|array|WP_Error|null Tag data in type defined by $output parameter. WP_Error if $tag is empty, null if it does not exist.
287 function get_tag( $tag, $output = OBJECT, $filter = 'raw' ) {
288 return get_term( $tag, 'post_tag', $output, $filter );
294 * Remove the category cache data based on ID.
298 * @param int $id Category ID
300 function clean_category_cache( $id ) {
301 clean_term_cache( $id, 'category' );
305 * Update category structure to old pre 2.3 from new taxonomy structure.
307 * This function was added for the taxonomy support to update the new category
308 * structure with the old category one. This will maintain compatibility with
309 * plugins and themes which depend on the old key or property names.
311 * The parameter should only be passed a variable and not create the array or
312 * object inline to the parameter. The reason for this is that parameter is
313 * passed by reference and PHP will fail unless it has the variable.
315 * There is no return value, because everything is updated on the variable you
316 * pass to it. This is one of the features with using pass by reference in PHP.
321 * @param array|object $category Category Row object or array
323 function _make_cat_compat( &$category ) {
324 if ( is_object( $category ) ) {
325 $category->cat_ID = &$category->term_id;
326 $category->category_count = &$category->count;
327 $category->category_description = &$category->description;
328 $category->cat_name = &$category->name;
329 $category->category_nicename = &$category->slug;
330 $category->category_parent = &$category->parent;
331 } elseif ( is_array( $category ) && isset( $category['term_id'] ) ) {
332 $category['cat_ID'] = &$category['term_id'];
333 $category['category_count'] = &$category['count'];
334 $category['category_description'] = &$category['description'];
335 $category['cat_name'] = &$category['name'];
336 $category['category_nicename'] = &$category['slug'];
337 $category['category_parent'] = &$category['parent'];