1 <?php

     2 /**

     3  * Taxonomy API

     4  *

     5  * @package WordPress

     6  * @subpackage Taxonomy

     7  * @since 2.3.0

     8  */

     9 

    10 //

    11 // Taxonomy Registration

    12 //

    13 

    14 /**

    15  * Creates the initial taxonomies when 'init' action is fired.

    16  */

    17 function create_initial_taxonomies() {

    18 	register_taxonomy( 'category', 'post', array('hierarchical' => true, 'update_count_callback' => '_update_post_term_count', 'label' => __('Categories'), 'query_var' => false, 'rewrite' => false) ) ;

    19 	register_taxonomy( 'post_tag', 'post', array('hierarchical' => false, 'update_count_callback' => '_update_post_term_count', 'label' => __('Post Tags'), 'query_var' => false, 'rewrite' => false) ) ;

    20 	register_taxonomy( 'link_category', 'link', array('hierarchical' => false, 'label' => __('Categories'), 'query_var' => false, 'rewrite' => false) ) ;

    21 }

    22 add_action( 'init', 'create_initial_taxonomies', 0 ); // highest priority

    23 

    24 /**

    25  * Return all of the taxonomy names that are of $object_type.

    26  *

    27  * It appears that this function can be used to find all of the names inside of

    28  * $wp_taxonomies global variable.

    29  *

    30  * <code><?php $taxonomies = get_object_taxonomies('post'); ?></code> Should

    31  * result in <code>Array('category', 'post_tag')</code>

    32  *

    33  * @package WordPress

    34  * @subpackage Taxonomy

    35  * @since 2.3.0

    36  *

    37  * @uses $wp_taxonomies

    38  *

    39  * @param array|string|object $object Name of the type of taxonomy object, or an object (row from posts)

    40  * @return array The names of all taxonomy of $object_type.

    41  */

    42 function get_object_taxonomies($object) {

    43 	global $wp_taxonomies;

    44 

    45 	if ( is_object($object) ) {

    46 		if ( $object->post_type == 'attachment' )

    47 			return get_attachment_taxonomies($object);

    48 		$object = $object->post_type;

    49 	}

    50 

    51 	$object = (array) $object;

    52 

    53 	$taxonomies = array();

    54 	foreach ( (array) $wp_taxonomies as $taxonomy ) {

    55 		if ( array_intersect($object, (array) $taxonomy->object_type) )

    56 			$taxonomies[] = $taxonomy->name;

    57 	}

    58 

    59 	return $taxonomies;

    60 }

    61 

    62 /**

    63  * Retrieves the taxonomy object of $taxonomy.

    64  *

    65  * The get_taxonomy function will first check that the parameter string given

    66  * is a taxonomy object and if it is, it will return it.

    67  *

    68  * @package WordPress

    69  * @subpackage Taxonomy

    70  * @since 2.3.0

    71  *

    72  * @uses $wp_taxonomies

    73  * @uses is_taxonomy() Checks whether taxonomy exists

    74  *

    75  * @param string $taxonomy Name of taxonomy object to return

    76  * @return object|bool The Taxonomy Object or false if $taxonomy doesn't exist

    77  */

    78 function get_taxonomy( $taxonomy ) {

    79 	global $wp_taxonomies;

    80 

    81 	if ( ! is_taxonomy($taxonomy) )

    82 		return false;

    83 

    84 	return $wp_taxonomies[$taxonomy];

    85 }

    86 

    87 /**

    88  * Checks that the taxonomy name exists.

    89  *

    90  * @package WordPress

    91  * @subpackage Taxonomy

    92  * @since 2.3.0

    93  *

    94  * @uses $wp_taxonomies

    95  *

    96  * @param string $taxonomy Name of taxonomy object

    97  * @return bool Whether the taxonomy exists or not.

    98  */

    99 function is_taxonomy( $taxonomy ) {

   100 	global $wp_taxonomies;

   101 

   102 	return isset($wp_taxonomies[$taxonomy]);

   103 }

   104 

   105 /**

   106  * Whether the taxonomy object is hierarchical.

   107  *

   108  * Checks to make sure that the taxonomy is an object first. Then Gets the

   109  * object, and finally returns the hierarchical value in the object.

   110  *

   111  * A false return value might also mean that the taxonomy does not exist.

   112  *

   113  * @package WordPress

   114  * @subpackage Taxonomy

   115  * @since 2.3.0

   116  *

   117  * @uses is_taxonomy() Checks whether taxonomy exists

   118  * @uses get_taxonomy() Used to get the taxonomy object

   119  *

   120  * @param string $taxonomy Name of taxonomy object

   121  * @return bool Whether the taxonomy is hierarchical

   122  */

   123 function is_taxonomy_hierarchical($taxonomy) {

   124 	if ( ! is_taxonomy($taxonomy) )

   125 		return false;

   126 

   127 	$taxonomy = get_taxonomy($taxonomy);

   128 	return $taxonomy->hierarchical;

   129 }

   130 

   131 /**

   132  * Create or modify a taxonomy object. Do not use before init.

   133  *

   134  * A simple function for creating or modifying a taxonomy object based on the

   135  * parameters given. The function will accept an array (third optional

   136  * parameter), along with strings for the taxonomy name and another string for

   137  * the object type.

   138  *

   139  * Nothing is returned, so expect error maybe or use is_taxonomy() to check

   140  * whether taxonomy exists.

   141  *

   142  * Optional $args contents:

   143  *

   144  * hierarachical - has some defined purpose at other parts of the API and is a

   145  * boolean value.

   146  *

   147  * update_count_callback - works much like a hook, in that it will be called

   148  * when the count is updated.

   149  *

   150  * rewrite - false to prevent rewrite, or array('slug'=>$slug) to customize

   151  * permastruct; default will use $taxonomy as slug.

   152  *

   153  * query_var - false to prevent queries, or string to customize query var

   154  * (?$query_var=$term); default will use $taxonomy as query var.

   155  *

   156  * @package WordPress

   157  * @subpackage Taxonomy

   158  * @since 2.3.0

   159  * @uses $wp_taxonomies Inserts new taxonomy object into the list

   160  * @uses $wp_rewrite Adds rewrite tags and permastructs

   161  * @uses $wp Adds query vars

   162  *

   163  * @param string $taxonomy Name of taxonomy object

   164  * @param array|string $object_type Name of the object type for the taxonomy object.

   165  * @param array|string $args See above description for the two keys values.

   166  */

   167 function register_taxonomy( $taxonomy, $object_type, $args = array() ) {

   168 	global $wp_taxonomies, $wp_rewrite, $wp;

   169 

   170 	if (!is_array($wp_taxonomies))

   171 		$wp_taxonomies = array();

   172 

   173 	$defaults = array('hierarchical' => false, 'update_count_callback' => '', 'rewrite' => true, 'query_var' => true);

   174 	$args = wp_parse_args($args, $defaults);

   175 

   176 	if ( false !== $args['query_var'] && !empty($wp) ) {

   177 		if ( true === $args['query_var'] )

   178 			$args['query_var'] = $taxonomy;

   179 		$args['query_var'] = sanitize_title_with_dashes($args['query_var']);

   180 		$wp->add_query_var($args['query_var']);

   181 	}

   182 

   183 	if ( false !== $args['rewrite'] && !empty($wp_rewrite) ) {

   184 		if ( !is_array($args['rewrite']) )

   185 			$args['rewrite'] = array();

   186 		if ( !isset($args['rewrite']['slug']) )

   187 			$args['rewrite']['slug'] = sanitize_title_with_dashes($taxonomy);

   188 		$wp_rewrite->add_rewrite_tag("%$taxonomy%", '([^/]+)', $args['query_var'] ? "{$args['query_var']}=" : "taxonomy=$taxonomy&term=$term");

   189 		$wp_rewrite->add_permastruct($taxonomy, "{$args['rewrite']['slug']}/%$taxonomy%");

   190 	}

   191 

   192 	$args['name'] = $taxonomy;

   193 	$args['object_type'] = $object_type;

   194 	$wp_taxonomies[$taxonomy] = (object) $args;

   195 }

   196 

   197 //

   198 // Term API

   199 //

   200 

   201 /**

   202  * Retrieve object_ids of valid taxonomy and term.

   203  *

   204  * The strings of $taxonomies must exist before this function will continue. On

   205  * failure of finding a valid taxonomy, it will return an WP_Error class, kind

   206  * of like Exceptions in PHP 5, except you can't catch them. Even so, you can

   207  * still test for the WP_Error class and get the error message.

   208  *

   209  * The $terms aren't checked the same as $taxonomies, but still need to exist

   210  * for $object_ids to be returned.

   211  *

   212  * It is possible to change the order that object_ids is returned by either

   213  * using PHP sort family functions or using the database by using $args with

   214  * either ASC or DESC array. The value should be in the key named 'order'.

   215  *

   216  * @package WordPress

   217  * @subpackage Taxonomy

   218  * @since 2.3.0

   219  *

   220  * @uses $wpdb

   221  * @uses wp_parse_args() Creates an array from string $args.

   222  *

   223  * @param string|array $terms String of term or array of string values of terms that will be used

   224  * @param string|array $taxonomies String of taxonomy name or Array of string values of taxonomy names

   225  * @param array|string $args Change the order of the object_ids, either ASC or DESC

   226  * @return WP_Error|array If the taxonomy does not exist, then WP_Error will be returned. On success

   227  *	the array can be empty meaning that there are no $object_ids found or it will return the $object_ids found.

   228  */

   229 function get_objects_in_term( $terms, $taxonomies, $args = array() ) {

   230 	global $wpdb;

   231 

   232 	if ( !is_array( $terms) )

   233 		$terms = array($terms);

   234 

   235 	if ( !is_array($taxonomies) )

   236 		$taxonomies = array($taxonomies);

   237 

   238 	foreach ( (array) $taxonomies as $taxonomy ) {

   239 		if ( ! is_taxonomy($taxonomy) )

   240 			return new WP_Error('invalid_taxonomy', __('Invalid Taxonomy'));

   241 	}

   242 

   243 	$defaults = array('order' => 'ASC');

   244 	$args = wp_parse_args( $args, $defaults );

   245 	extract($args, EXTR_SKIP);

   246 

   247 	$order = ( 'desc' == strtolower($order) ) ? 'DESC' : 'ASC';

   248 

   249 	$terms = array_map('intval', $terms);

   250 

   251 	$taxonomies = "'" . implode("', '", $taxonomies) . "'";

   252 	$terms = "'" . implode("', '", $terms) . "'";

   253 

   254 	$object_ids = $wpdb->get_col("SELECT tr.object_id FROM $wpdb->term_relationships AS tr INNER JOIN $wpdb->term_taxonomy AS tt ON tr.term_taxonomy_id = tt.term_taxonomy_id WHERE tt.taxonomy IN ($taxonomies) AND tt.term_id IN ($terms) ORDER BY tr.object_id $order");

   255 

   256 	if ( ! $object_ids )

   257 		return array();

   258 

   259 	return $object_ids;

   260 }

   261 

   262 /**

   263  * Get all Term data from database by Term ID.

   264  *

   265  * The usage of the get_term function is to apply filters to a term object. It

   266  * is possible to get a term object from the database before applying the

   267  * filters.

   268  *

   269  * $term ID must be part of $taxonomy, to get from the database. Failure, might

   270  * be able to be captured by the hooks. Failure would be the same value as $wpdb

   271  * returns for the get_row method.

   272  *

   273  * There are two hooks, one is specifically for each term, named 'get_term', and

   274  * the second is for the taxonomy name, 'term_$taxonomy'. Both hooks gets the

   275  * term object, and the taxonomy name as parameters. Both hooks are expected to

   276  * return a Term object.

   277  *

   278  * 'get_term' hook - Takes two parameters the term Object and the taxonomy name.

   279  * Must return term object. Used in get_term() as a catch-all filter for every

   280  * $term.

   281  *

   282  * 'get_$taxonomy' hook - Takes two parameters the term Object and the taxonomy

   283  * name. Must return term object. $taxonomy will be the taxonomy name, so for

   284  * example, if 'category', it would be 'get_category' as the filter name. Useful

   285  * for custom taxonomies or plugging into default taxonomies.

   286  *

   287  * @package WordPress

   288  * @subpackage Taxonomy

   289  * @since 2.3.0

   290  *

   291  * @uses $wpdb

   292  * @uses sanitize_term() Cleanses the term based on $filter context before returning.

   293  * @see sanitize_term_field() The $context param lists the available values for get_term_by() $filter param.

   294  *

   295  * @param int|object $term If integer, will get from database. If object will apply filters and return $term.

   296  * @param string $taxonomy Taxonomy name that $term is part of.

   297  * @param string $output Constant OBJECT, ARRAY_A, or ARRAY_N

   298  * @param string $filter Optional, default is raw or no WordPress defined filter will applied.

   299  * @return mixed|null|WP_Error Term Row from database. Will return null if $term is empty. If taxonomy does not

   300  * exist then WP_Error will be returned.

   301  */

   302 function &get_term($term, $taxonomy, $output = OBJECT, $filter = 'raw') {

   303 	global $wpdb;

   304 	$null = null;

   305 

   306 	if ( empty($term) ) {

   307 		$error = new WP_Error('invalid_term', __('Empty Term'));

   308 		return $error;

   309 	}

   310 

   311 	if ( ! is_taxonomy($taxonomy) ) {

   312 		$error = new WP_Error('invalid_taxonomy', __('Invalid Taxonomy'));

   313 		return $error;

   314 	}

   315 

   316 	if ( is_object($term) && empty($term->filter) ) {

   317 		wp_cache_add($term->term_id, $term, $taxonomy);

   318 		$_term = $term;

   319 	} else {

   320 		if ( is_object($term) )

   321 			$term = $term->term_id;

   322 		$term = (int) $term;

   323 		if ( ! $_term = wp_cache_get($term, $taxonomy) ) {

   324 			$_term = $wpdb->get_row( $wpdb->prepare( "SELECT t.*, tt.* FROM $wpdb->terms AS t INNER JOIN $wpdb->term_taxonomy AS tt ON t.term_id = tt.term_id WHERE tt.taxonomy = %s AND t.term_id = %s LIMIT 1", $taxonomy, $term) );

   325 			if ( ! $_term )

   326 				return $null;

   327 			wp_cache_add($term, $_term, $taxonomy);

   328 		}

   329 	}

   330 

   331 	$_term = apply_filters('get_term', $_term, $taxonomy);

   332 	$_term = apply_filters("get_$taxonomy", $_term, $taxonomy);

   333 	$_term = sanitize_term($_term, $taxonomy, $filter);

   334 

   335 	if ( $output == OBJECT ) {

   336 		return $_term;

   337 	} elseif ( $output == ARRAY_A ) {

   338 		$__term = get_object_vars($_term);

   339 		return $__term;

   340 	} elseif ( $output == ARRAY_N ) {

   341 		$__term = array_values(get_object_vars($_term));

   342 		return $__term;

   343 	} else {

   344 		return $_term;

   345 	}

   346 }

   347 

   348 /**

   349  * Get all Term data from database by Term field and data.

   350  *

   351  * Warning: $value is not escaped for 'name' $field. You must do it yourself, if

   352  * required.

   353  *

   354  * The default $field is 'id', therefore it is possible to also use null for

   355  * field, but not recommended that you do so.

   356  *

   357  * If $value does not exist, the return value will be false. If $taxonomy exists

   358  * and $field and $value combinations exist, the Term will be returned.

   359  *

   360  * @package WordPress

   361  * @subpackage Taxonomy

   362  * @since 2.3.0

   363  *

   364  * @uses $wpdb

   365  * @uses sanitize_term() Cleanses the term based on $filter context before returning.

   366  * @see sanitize_term_field() The $context param lists the available values for get_term_by() $filter param.

   367  *

   368  * @param string $field Either 'slug', 'name', or 'id'

   369  * @param string|int $value Search for this term value

   370  * @param string $taxonomy Taxonomy Name

   371  * @param string $output Constant OBJECT, ARRAY_A, or ARRAY_N

   372  * @param string $filter Optional, default is raw or no WordPress defined filter will applied.

   373  * @return mixed Term Row from database. Will return false if $taxonomy does not exist or $term was not found.

   374  */

   375 function get_term_by($field, $value, $taxonomy, $output = OBJECT, $filter = 'raw') {

   376 	global $wpdb;

   377 

   378 	if ( ! is_taxonomy($taxonomy) )

   379 		return false;

   380 

   381 	if ( 'slug' == $field ) {

   382 		$field = 't.slug';

   383 		$value = sanitize_title($value);

   384 		if ( empty($value) )

   385 			return false;

   386 	} else if ( 'name' == $field ) {

   387 		// Assume already escaped

   388 		$value = stripslashes($value);

   389 		$field = 't.name';

   390 	} else {

   391 		$field = 't.term_id';

   392 		$value = (int) $value;

   393 	}

   394 

   395 	$term = $wpdb->get_row( $wpdb->prepare( "SELECT t.*, tt.* FROM $wpdb->terms AS t INNER JOIN $wpdb->term_taxonomy AS tt ON t.term_id = tt.term_id WHERE tt.taxonomy = %s AND $field = %s LIMIT 1", $taxonomy, $value) );

   396 	if ( !$term )

   397 		return false;

   398 

   399 	wp_cache_add($term->term_id, $term, $taxonomy);

   400 

   401 	$term = sanitize_term($term, $taxonomy, $filter);

   402 

   403 	if ( $output == OBJECT ) {

   404 		return $term;

   405 	} elseif ( $output == ARRAY_A ) {

   406 		return get_object_vars($term);

   407 	} elseif ( $output == ARRAY_N ) {

   408 		return array_values(get_object_vars($term));

   409 	} else {

   410 		return $term;

   411 	}

   412 }

   413 

   414 /**

   415  * Merge all term children into a single array of their IDs.

   416  *

   417  * This recursive function will merge all of the children of $term into the same

   418  * array of term IDs. Only useful for taxonomies which are hierarchical.

   419  *

   420  * Will return an empty array if $term does not exist in $taxonomy.

   421  *

   422  * @package WordPress

   423  * @subpackage Taxonomy

   424  * @since 2.3.0

   425  *

   426  * @uses $wpdb

   427  * @uses _get_term_hierarchy()

   428  * @uses get_term_children() Used to get the children of both $taxonomy and the parent $term

   429  *

   430  * @param string $term ID of Term to get children

   431  * @param string $taxonomy Taxonomy Name

   432  * @return array|WP_Error List of Term Objects. WP_Error returned if $taxonomy does not exist

   433  */

   434 function get_term_children( $term_id, $taxonomy ) {

   435 	if ( ! is_taxonomy($taxonomy) )

   436 		return new WP_Error('invalid_taxonomy', __('Invalid Taxonomy'));

   437 

   438 	$term_id = intval( $term_id );

   439 

   440 	$terms = _get_term_hierarchy($taxonomy);

   441 

   442 	if ( ! isset($terms[$term_id]) )

   443 		return array();

   444 

   445 	$children = $terms[$term_id];

   446 

   447 	foreach ( (array) $terms[$term_id] as $child ) {

   448 		if ( isset($terms[$child]) )

   449 			$children = array_merge($children, get_term_children($child, $taxonomy));

   450 	}

   451 

   452 	return $children;

   453 }

   454 

   455 /**

   456  * Get sanitized Term field.

   457  *

   458  * Does checks for $term, based on the $taxonomy. The function is for contextual

   459  * reasons and for simplicity of usage. See sanitize_term_field() for more

   460  * information.

   461  *

   462  * @package WordPress

   463  * @subpackage Taxonomy

   464  * @since 2.3.0

   465  *

   466  * @uses sanitize_term_field() Passes the return value in sanitize_term_field on success.

   467  *

   468  * @param string $field Term field to fetch

   469  * @param int $term Term ID

   470  * @param string $taxonomy Taxonomy Name

   471  * @param string $context Optional, default is display. Look at sanitize_term_field() for available options.

   472  * @return mixed Will return an empty string if $term is not an object or if $field is not set in $term.

   473  */

   474 function get_term_field( $field, $term, $taxonomy, $context = 'display' ) {

   475 	$term = (int) $term;

   476 	$term = get_term( $term, $taxonomy );

   477 	if ( is_wp_error($term) )

   478 		return $term;

   479 

   480 	if ( !is_object($term) )

   481 		return '';

   482 

   483 	if ( !isset($term->$field) )

   484 		return '';

   485 

   486 	return sanitize_term_field($field, $term->$field, $term->term_id, $taxonomy, $context);

   487 }

   488 

   489 /**

   490  * Sanitizes Term for editing.

   491  *

   492  * Return value is sanitize_term() and usage is for sanitizing the term for

   493  * editing. Function is for contextual and simplicity.

   494  *

   495  * @package WordPress

   496  * @subpackage Taxonomy

   497  * @since 2.3.0

   498  *

   499  * @uses sanitize_term() Passes the return value on success

   500  *

   501  * @param int|object $id Term ID or Object

   502  * @param string $taxonomy Taxonomy Name

   503  * @return mixed|null|WP_Error Will return empty string if $term is not an object.

   504  */

   505 function get_term_to_edit( $id, $taxonomy ) {

   506 	$term = get_term( $id, $taxonomy );

   507 

   508 	if ( is_wp_error($term) )

   509 		return $term;

   510 

   511 	if ( !is_object($term) )

   512 		return '';

   513 

   514 	return sanitize_term($term, $taxonomy, 'edit');

   515 }

   516 

   517 /**

   518  * Retrieve the terms in a given taxonomy or list of taxonomies.

   519  *

   520  * You can fully inject any customizations to the query before it is sent, as

   521  * well as control the output with a filter.

   522  *

   523  * The 'get_terms' filter will be called when the cache has the term and will

   524  * pass the found term along with the array of $taxonomies and array of $args.

   525  * This filter is also called before the array of terms is passed and will pass

   526  * the array of terms, along with the $taxonomies and $args.

   527  *

   528  * The 'list_terms_exclusions' filter passes the compiled exclusions along with

   529  * the $args.

   530  *

   531  * The 'get_terms_orderby' filter passes the ORDER BY clause for the query

   532  * along with the $args array.

   533 

   534  * The 'get_terms_fields' filter passes the fields for the SELECT query

   535  * along with the $args array.

   536  *

   537  * The list of arguments that $args can contain, which will overwrite the defaults:

   538  *

   539  * orderby - Default is 'name'. Can be name, count, term_group, slug or nothing

   540  * (will use term_id), Passing a custom value other than these will cause it to

   541  * order based on the custom value.

   542  *

   543  * order - Default is ASC. Can use DESC.

   544  *

   545  * hide_empty - Default is true. Will not return empty terms, which means

   546  * terms whose count is 0 according to the given taxonomy.

   547  *

   548  * exclude - Default is an empty string.  A comma- or space-delimited string

   549  * of term ids to exclude from the return array.  If 'include' is non-empty,

   550  * 'exclude' is ignored.

   551  *

   552  * exclude_tree - A comma- or space-delimited string of term ids to exclude

   553  * from the return array, along with all of their descendant terms according to

   554  * the primary taxonomy.  If 'include' is non-empty, 'exclude_tree' is ignored.

   555  *

   556  * include - Default is an empty string.  A comma- or space-delimited string

   557  * of term ids to include in the return array.

   558  *

   559  * number - The maximum number of terms to return.  Default is empty.

   560  *

   561  * offset - The number by which to offset the terms query.

   562  *

   563  * fields - Default is 'all', which returns an array of term objects.

   564  * If 'fields' is 'ids' or 'names', returns an array of

   565  * integers or strings, respectively.

   566  *

   567  * slug - Returns terms whose "slug" matches this value. Default is empty string.

   568  *

   569  * hierarchical - Whether to include terms that have non-empty descendants

   570  * (even if 'hide_empty' is set to true).

   571  *

   572  * search - Returned terms' names will contain the value of 'search',

   573  * case-insensitive.  Default is an empty string.

   574  *

   575  * name__like - Returned terms' names will begin with the value of 'name__like',

   576  * case-insensitive. Default is empty string.

   577  *

   578  * The argument 'pad_counts', if set to true will include the quantity of a term's

   579  * children in the quantity of each term's "count" object variable.

   580  *

   581  * The 'get' argument, if set to 'all' instead of its default empty string,

   582  * returns terms regardless of ancestry or whether the terms are empty.

   583  *

   584  * The 'child_of' argument, when used, should be set to the integer of a term ID.  Its default

   585  * is 0.  If set to a non-zero value, all returned terms will be descendants

   586  * of that term according to the given taxonomy.  Hence 'child_of' is set to 0

   587  * if more than one taxonomy is passed in $taxonomies, because multiple taxonomies

   588  * make term ancestry ambiguous.

   589  *

   590  * The 'parent' argument, when used, should be set to the integer of a term ID.  Its default is

   591  * the empty string '', which has a different meaning from the integer 0.

   592  * If set to an integer value, all returned terms will have as an immediate

   593  * ancestor the term whose ID is specified by that integer according to the given taxonomy.

   594  * The 'parent' argument is different from 'child_of' in that a term X is considered a 'parent'

   595  * of term Y only if term X is the father of term Y, not its grandfather or great-grandfather, etc.

   596  *

   597  * @package WordPress

   598  * @subpackage Taxonomy

   599  * @since 2.3.0

   600  *

   601  * @uses $wpdb

   602  * @uses wp_parse_args() Merges the defaults with those defined by $args and allows for strings.

   603  *

   604  * @param string|array Taxonomy name or list of Taxonomy names

   605  * @param string|array $args The values of what to search for when returning terms

   606  * @return array|WP_Error List of Term Objects and their children. Will return WP_Error, if any of $taxonomies do not exist.

   607  */

   608 function &get_terms($taxonomies, $args = '') {

   609 	global $wpdb;

   610 	$empty_array = array();

   611 

   612 	$single_taxonomy = false;

   613 	if ( !is_array($taxonomies) ) {

   614 		$single_taxonomy = true;

   615 		$taxonomies = array($taxonomies);

   616 	}

   617 

   618 	foreach ( (array) $taxonomies as $taxonomy ) {

   619 		if ( ! is_taxonomy($taxonomy) ) {

   620 			$error = & new WP_Error('invalid_taxonomy', __('Invalid Taxonomy'));

   621 			return $error;

   622 		}

   623 	}

   624 

   625 	$in_taxonomies = "'" . implode("', '", $taxonomies) . "'";

   626 

   627 	$defaults = array('orderby' => 'name', 'order' => 'ASC',

   628 		'hide_empty' => true, 'exclude' => '', 'exclude_tree' => '', 'include' => '',

   629 		'number' => '', 'fields' => 'all', 'slug' => '', 'parent' => '',

   630 		'hierarchical' => true, 'child_of' => 0, 'get' => '', 'name__like' => '',

   631 		'pad_counts' => false, 'offset' => '', 'search' => '');

   632 	$args = wp_parse_args( $args, $defaults );

   633 	$args['number'] = absint( $args['number'] );

   634 	$args['offset'] = absint( $args['offset'] );

   635 	if ( !$single_taxonomy || !is_taxonomy_hierarchical($taxonomies[0]) ||

   636 		'' !== $args['parent'] ) {

   637 		$args['child_of'] = 0;

   638 		$args['hierarchical'] = false;

   639 		$args['pad_counts'] = false;

   640 	}

   641 

   642 	if ( 'all' == $args['get'] ) {

   643 		$args['child_of'] = 0;

   644 		$args['hide_empty'] = 0;

   645 		$args['hierarchical'] = false;

   646 		$args['pad_counts'] = false;

   647 	}

   648 	extract($args, EXTR_SKIP);

   649 

   650 	if ( $child_of ) {

   651 		$hierarchy = _get_term_hierarchy($taxonomies[0]);

   652 		if ( !isset($hierarchy[$child_of]) )

   653 			return $empty_array;

   654 	}

   655 

   656 	if ( $parent ) {

   657 		$hierarchy = _get_term_hierarchy($taxonomies[0]);

   658 		if ( !isset($hierarchy[$parent]) )

   659 			return $empty_array;

   660 	}

   661 

   662 	// $args can be whatever, only use the args defined in defaults to compute the key

   663 	$filter_key = ( has_filter('list_terms_exclusions') ) ? serialize($GLOBALS['wp_filter']['list_terms_exclusions']) : '';

   664 	$key = md5( serialize( compact(array_keys($defaults)) ) . serialize( $taxonomies ) . $filter_key );

   665 	$last_changed = wp_cache_get('last_changed', 'terms');

   666 	if ( !$last_changed ) {

   667 		$last_changed = time();

   668 		wp_cache_set('last_changed', $last_changed, 'terms');

   669 	}

   670 	$cache_key = "get_terms:$key:$last_changed";

   671 	$cache = wp_cache_get( $cache_key, 'terms' );

   672 	if ( false !== $cache ) {

   673 		$cache = apply_filters('get_terms', $cache, $taxonomies, $args);

   674 		return $cache;

   675 	}

   676 

   677 	$_orderby = strtolower($orderby);

   678 	if ( 'count' == $_orderby )

   679 		$orderby = 'tt.count';

   680 	else if ( 'name' == $_orderby )

   681 		$orderby = 't.name';

   682 	else if ( 'slug' == $_orderby )

   683 		$orderby = 't.slug';

   684 	else if ( 'term_group' == $_orderby )

   685 		$orderby = 't.term_group';

   686 	elseif ( empty($_orderby) || 'id' == $_orderby )

   687 		$orderby = 't.term_id';

   688 

   689 	$orderby = apply_filters( 'get_terms_orderby', $orderby, $args );

   690 

   691 	$where = '';

   692 	$inclusions = '';

   693 	if ( !empty($include) ) {

   694 		$exclude = '';

   695 		$exclude_tree = '';

   696 		$interms = preg_split('/[\s,]+/',$include);

   697 		if ( count($interms) ) {

   698 			foreach ( (array) $interms as $interm ) {

   699 				if (empty($inclusions))

   700 					$inclusions = ' AND ( t.term_id = ' . intval($interm) . ' ';

   701 				else

   702 					$inclusions .= ' OR t.term_id = ' . intval($interm) . ' ';

   703 			}

   704 		}

   705 	}

   706 

   707 	if ( !empty($inclusions) )

   708 		$inclusions .= ')';

   709 	$where .= $inclusions;

   710 

   711 	$exclusions = '';

   712 	if ( ! empty( $exclude_tree ) ) {

   713 		$excluded_trunks = preg_split('/[\s,]+/',$exclude_tree);

   714 		foreach( (array) $excluded_trunks as $extrunk ) {

   715 			$excluded_children = (array) get_terms($taxonomies[0], array('child_of' => intval($extrunk), 'fields' => 'ids'));

   716 			$excluded_children[] = $extrunk;

   717 			foreach( (array) $excluded_children as $exterm ) {

   718 				if ( empty($exclusions) )

   719 					$exclusions = ' AND ( t.term_id <> ' . intval($exterm) . ' ';

   720 				else

   721 					$exclusions .= ' AND t.term_id <> ' . intval($exterm) . ' ';

   722 

   723 			}

   724 		}

   725 	}

   726 	if ( !empty($exclude) ) {

   727 		$exterms = preg_split('/[\s,]+/',$exclude);

   728 		if ( count($exterms) ) {

   729 			foreach ( (array) $exterms as $exterm ) {

   730 				if ( empty($exclusions) )

   731 					$exclusions = ' AND ( t.term_id <> ' . intval($exterm) . ' ';

   732 				else

   733 					$exclusions .= ' AND t.term_id <> ' . intval($exterm) . ' ';

   734 			}

   735 		}

   736 	}

   737 

   738 	if ( !empty($exclusions) )

   739 		$exclusions .= ')';

   740 	$exclusions = apply_filters('list_terms_exclusions', $exclusions, $args );

   741 	$where .= $exclusions;

   742 

   743 	if ( !empty($slug) ) {

   744 		$slug = sanitize_title($slug);

   745 		$where .= " AND t.slug = '$slug'";

   746 	}

   747 

   748 	if ( !empty($name__like) )

   749 		$where .= " AND t.name LIKE '{$name__like}%'";

   750 

   751 	if ( '' !== $parent ) {

   752 		$parent = (int) $parent;

   753 		$where .= " AND tt.parent = '$parent'";

   754 	}

   755 

   756 	if ( $hide_empty && !$hierarchical )

   757 		$where .= ' AND tt.count > 0';

   758 

   759 	// don't limit the query results when we have to descend the family tree

   760 	if ( ! empty($number) && ! $hierarchical && empty( $child_of ) && '' === $parent ) {

   761 		if( $offset )

   762 			$limit = 'LIMIT ' . $offset . ',' . $number;

   763 		else

   764 			$limit = 'LIMIT ' . $number;

   765 

   766 	} else

   767 		$limit = '';

   768 

   769 	if ( !empty($search) ) {

   770 		$search = like_escape($search);

   771 		$where .= " AND (t.name LIKE '%$search%')";

   772 	}

   773 

   774 	$selects = array();

   775 	if ( 'all' == $fields )

   776 		$selects = array('t.*', 'tt.*');

   777 	else if ( 'ids' == $fields )

   778 		$selects = array('t.term_id', 'tt.parent', 'tt.count');

   779 	else if ( 'names' == $fields )

   780 		$selects = array('t.term_id', 'tt.parent', 'tt.count', 't.name');

   781         $select_this = implode(', ', apply_filters( 'get_terms_fields', $selects, $args ));

   782 

   783 	$query = "SELECT $select_this FROM $wpdb->terms AS t INNER JOIN $wpdb->term_taxonomy AS tt ON t.term_id = tt.term_id WHERE tt.taxonomy IN ($in_taxonomies) $where ORDER BY $orderby $order $limit";

   784 

   785 	$terms = $wpdb->get_results($query);

   786 	if ( 'all' == $fields ) {

   787 		update_term_cache($terms);

   788 	}

   789 

   790 	if ( empty($terms) ) {

   791 		wp_cache_add( $cache_key, array(), 'terms' );

   792 		$terms = apply_filters('get_terms', array(), $taxonomies, $args);

   793 		return $terms;

   794 	}

   795 

   796 	if ( $child_of ) {

   797 		$children = _get_term_hierarchy($taxonomies[0]);

   798 		if ( ! empty($children) )

   799 			$terms = & _get_term_children($child_of, $terms, $taxonomies[0]);

   800 	}

   801 

   802 	// Update term counts to include children.

   803 	if ( $pad_counts && 'all' == $fields )

   804 		_pad_term_counts($terms, $taxonomies[0]);

   805 

   806 	// Make sure we show empty categories that have children.

   807 	if ( $hierarchical && $hide_empty && is_array($terms) ) {

   808 		foreach ( $terms as $k => $term ) {

   809 			if ( ! $term->count ) {

   810 				$children = _get_term_children($term->term_id, $terms, $taxonomies[0]);

   811 				if( is_array($children) )

   812 					foreach ( $children as $child )

   813 						if ( $child->count )

   814 							continue 2;

   815 

   816 				// It really is empty

   817 				unset($terms[$k]);

   818 			}

   819 		}

   820 	}

   821 	reset ( $terms );

   822 

   823 	$_terms = array();

   824 	if ( 'ids' == $fields ) {

   825 		while ( $term = array_shift($terms) )

   826 			$_terms[] = $term->term_id;

   827 		$terms = $_terms;

   828 	} elseif ( 'names' == $fields ) {

   829 		while ( $term = array_shift($terms) )

   830 			$_terms[] = $term->name;

   831 		$terms = $_terms;

   832 	}

   833 

   834 	if ( 0 < $number && intval(@count($terms)) > $number ) {

   835 		$terms = array_slice($terms, $offset, $number);

   836 	}

   837 

   838 	wp_cache_add( $cache_key, $terms, 'terms' );

   839 

   840 	$terms = apply_filters('get_terms', $terms, $taxonomies, $args);

   841 	return $terms;

   842 }

   843 

   844 /**

   845  * Check if Term exists.

   846  *

   847  * Returns the index of a defined term, or 0 (false) if the term doesn't exist.

   848  *

   849  * @package WordPress

   850  * @subpackage Taxonomy

   851  * @since 2.3.0

   852  *

   853  * @uses $wpdb

   854  *

   855  * @param int|string $term The term to check

   856  * @param string $taxonomy The taxonomy name to use

   857  * @param int $parent ID of parent term under which to confine the exists search.

   858  * @return mixed Get the term id or Term Object, if exists.

   859  */

   860 function is_term($term, $taxonomy = '', $parent = 0) {

   861 	global $wpdb;

   862 

   863 	$select = "SELECT term_id FROM $wpdb->terms as t WHERE ";

   864 	$tax_select = "SELECT tt.term_id, tt.term_taxonomy_id FROM $wpdb->terms AS t INNER JOIN $wpdb->term_taxonomy as tt ON tt.term_id = t.term_id WHERE ";

   865 

   866 	if ( is_int($term) ) {

   867 		if ( 0 == $term )

   868 			return 0;

   869 		$where = 't.term_id = %d';

   870 		if ( !empty($taxonomy) )

   871 			return $wpdb->get_row( $wpdb->prepare( $tax_select . $where . " AND tt.taxonomy = %s", $term, $taxonomy ), ARRAY_A );

   872 		else

   873 			return $wpdb->get_var( $wpdb->prepare( $select . $where, $term ) );

   874 	}

   875 

   876 	$term = trim( stripslashes( $term ) );

   877 

   878 	if ( '' === $slug = sanitize_title($term) )

   879 		return 0;

   880 

   881 	$where = 't.slug = %s';

   882 	$else_where = 't.name = %s';

   883 	$where_fields = array($slug);

   884 	$else_where_fields = array($term);

   885 	if ( !empty($taxonomy) ) {

   886 		$parent = (int) $parent;

   887 		if ( $parent > 0 ) {

   888 			$where_fields[] = $parent;

   889 			$else_where_fields[] = $parent;

   890 			$where .= ' AND tt.parent = %d';

   891 			$else_where .= ' AND tt.parent = %d';

   892 		}

   893 

   894 		$where_fields[] = $taxonomy;

   895 		$else_where_fields[] = $taxonomy;

   896 

   897 		if ( $result = $wpdb->get_row( $wpdb->prepare("SELECT tt.term_id, tt.term_taxonomy_id FROM $wpdb->terms AS t INNER JOIN $wpdb->term_taxonomy as tt ON tt.term_id = t.term_id WHERE $where AND tt.taxonomy = %s", $where_fields), ARRAY_A) )

   898 			return $result;

   899 

   900 		return $wpdb->get_row( $wpdb->prepare("SELECT tt.term_id, tt.term_taxonomy_id FROM $wpdb->terms AS t INNER JOIN $wpdb->term_taxonomy as tt ON tt.term_id = t.term_id WHERE $else_where AND tt.taxonomy = %s", $else_where_fields), ARRAY_A);

   901 	}

   902 

   903 	if ( $result = $wpdb->get_var( $wpdb->prepare("SELECT term_id FROM $wpdb->terms as t WHERE $where", $where_fields) ) )

   904 		return $result;

   905 

   906 	return $wpdb->get_var( $wpdb->prepare("SELECT term_id FROM $wpdb->terms as t WHERE $else_where", $else_where_fields) );

   907 }

   908 

   909 /**

   910  * Sanitize Term all fields.

   911  *

   912  * Relys on sanitize_term_field() to sanitize the term. The difference is that

   913  * this function will sanitize <strong>all</strong> fields. The context is based

   914  * on sanitize_term_field().

   915  *

   916  * The $term is expected to be either an array or an object.

   917  *

   918  * @package WordPress

   919  * @subpackage Taxonomy

   920  * @since 2.3.0

   921  *

   922  * @uses sanitize_term_field Used to sanitize all fields in a term

   923  *

   924  * @param array|object $term The term to check

   925  * @param string $taxonomy The taxonomy name to use

   926  * @param string $context Default is 'display'.

   927  * @return array|object Term with all fields sanitized

   928  */

   929 function sanitize_term($term, $taxonomy, $context = 'display') {

   930 

   931 	if ( 'raw' == $context )

   932 		return $term;

   933 

   934 	$fields = array('term_id', 'name', 'description', 'slug', 'count', 'parent', 'term_group');

   935 

   936 	$do_object = false;

   937 	if ( is_object($term) )

   938 		$do_object = true;

   939 

   940 	$term_id = $do_object ? $term->term_id : (isset($term['term_id']) ? $term['term_id'] : 0);

   941 

   942 	foreach ( (array) $fields as $field ) {

   943 		if ( $do_object ) {

   944 			if ( isset($term->$field) )

   945 				$term->$field = sanitize_term_field($field, $term->$field, $term_id, $taxonomy, $context);

   946 		} else {

   947 			if ( isset($term[$field]) )

   948 				$term[$field] = sanitize_term_field($field, $term[$field], $term_id, $taxonomy, $context);

   949 		}

   950 	}

   951 

   952 	if ( $do_object )

   953 		$term->filter = $context;

   954 	else

   955 		$term['filter'] = $context;

   956 

   957 	return $term;

   958 }

   959 

   960 /**

   961  * Cleanse the field value in the term based on the context.

   962  *

   963  * Passing a term field value through the function should be assumed to have

   964  * cleansed the value for whatever context the term field is going to be used.

   965  *

   966  * If no context or an unsupported context is given, then default filters will

   967  * be applied.

   968  *

   969  * There are enough filters for each context to support a custom filtering

   970  * without creating your own filter function. Simply create a function that

   971  * hooks into the filter you need.

   972  *

   973  * @package WordPress

   974  * @subpackage Taxonomy

   975  * @since 2.3.0

   976  *

   977  * @uses $wpdb

   978  *

   979  * @param string $field Term field to sanitize

   980  * @param string $value Search for this term value

   981  * @param int $term_id Term ID

   982  * @param string $taxonomy Taxonomy Name

   983  * @param string $context Either edit, db, display, attribute, or js.

   984  * @return mixed sanitized field

   985  */

   986 function sanitize_term_field($field, $value, $term_id, $taxonomy, $context) {

   987 	if ( 'parent' == $field  || 'term_id' == $field || 'count' == $field || 'term_group' == $field ) {

   988 		$value = (int) $value;

   989 		if ( $value < 0 )

   990 			$value = 0;

   991 	}

   992 

   993 	if ( 'raw' == $context )

   994 		return $value;

   995 

   996 	if ( 'edit' == $context ) {

   997 		$value = apply_filters("edit_term_$field", $value, $term_id, $taxonomy);

   998 		$value = apply_filters("edit_${taxonomy}_$field", $value, $term_id);

   999 		if ( 'description' == $field )

  1000 			$value = format_to_edit($value);

  1001 		else

  1002 			$value = esc_attr($value);

  1003 	} else if ( 'db' == $context ) {

  1004 		$value = apply_filters("pre_term_$field", $value, $taxonomy);

  1005 		$value = apply_filters("pre_${taxonomy}_$field", $value);

  1006 		// Back compat filters

  1007 		if ( 'slug' == $field )

  1008 			$value = apply_filters('pre_category_nicename', $value);

  1009 

  1010 	} else if ( 'rss' == $context ) {

  1011 		$value = apply_filters("term_${field}_rss", $value, $taxonomy);

  1012 		$value = apply_filters("${taxonomy}_${field}_rss", $value);

  1013 	} else {

  1014 		// Use display filters by default.

  1015 		$value = apply_filters("term_$field", $value, $term_id, $taxonomy, $context);

  1016 		$value = apply_filters("${taxonomy}_$field", $value, $term_id, $context);

  1017 	}

  1018 

  1019 	if ( 'attribute' == $context )

  1020 		$value = esc_attr($value);

  1021 	else if ( 'js' == $context )

  1022 		$value = esc_js($value);

  1023 

  1024 	return $value;

  1025 }

  1026 

  1027 /**

  1028  * Count how many terms are in Taxonomy.

  1029  *

  1030  * Default $args is 'ignore_empty' which can be <code>'ignore_empty=true'</code>

  1031  * or <code>array('ignore_empty' => true);</code>.

  1032  *

  1033  * @package WordPress

  1034  * @subpackage Taxonomy

  1035  * @since 2.3.0

  1036  *

  1037  * @uses $wpdb

  1038  * @uses wp_parse_args() Turns strings into arrays and merges defaults into an array.

  1039  *

  1040  * @param string $taxonomy Taxonomy name

  1041  * @param array|string $args Overwrite defaults

  1042  * @return int How many terms are in $taxonomy

  1043  */

  1044 function wp_count_terms( $taxonomy, $args = array() ) {

  1045 	global $wpdb;

  1046 

  1047 	$defaults = array('ignore_empty' => false);

  1048 	$args = wp_parse_args($args, $defaults);

  1049 	extract($args, EXTR_SKIP);

  1050 

  1051 	$where = '';

  1052 	if ( $ignore_empty )

  1053 		$where = 'AND count > 0';

  1054 

  1055 	return $wpdb->get_var( $wpdb->prepare("SELECT COUNT(*) FROM $wpdb->term_taxonomy WHERE taxonomy = %s $where", $taxonomy) );

  1056 }

  1057 

  1058 /**

  1059  * Will unlink the term from the taxonomy.

  1060  *

  1061  * Will remove the term's relationship to the taxonomy, not the term or taxonomy

  1062  * itself. The term and taxonomy will still exist. Will require the term's

  1063  * object ID to perform the operation.

  1064  *

  1065  * @package WordPress

  1066  * @subpackage Taxonomy

  1067  * @since 2.3.0

  1068  * @uses $wpdb

  1069  *

  1070  * @param int $object_id The term Object Id that refers to the term

  1071  * @param string|array $taxonomy List of Taxonomy Names or single Taxonomy name.

  1072  */

  1073 function wp_delete_object_term_relationships( $object_id, $taxonomies ) {

  1074 	global $wpdb;

  1075 

  1076 	$object_id = (int) $object_id;

  1077 

  1078 	if ( !is_array($taxonomies) )

  1079 		$taxonomies = array($taxonomies);

  1080 

  1081 	foreach ( (array) $taxonomies as $taxonomy ) {

  1082 		$tt_ids = wp_get_object_terms($object_id, $taxonomy, 'fields=tt_ids');

  1083 		$in_tt_ids = "'" . implode("', '", $tt_ids) . "'";

  1084 		do_action( 'delete_term_relationships', $object_id, $tt_ids );

  1085 		$wpdb->query( $wpdb->prepare("DELETE FROM $wpdb->term_relationships WHERE object_id = %d AND term_taxonomy_id IN ($in_tt_ids)", $object_id) );

  1086 		do_action( 'deleted_term_relationships', $object_id, $tt_ids );

  1087 		wp_update_term_count($tt_ids, $taxonomy);

  1088 	}

  1089 }

  1090 

  1091 /**

  1092  * Removes a term from the database.

  1093  *

  1094  * If the term is a parent of other terms, then the children will be updated to

  1095  * that term's parent.

  1096  *

  1097  * The $args 'default' will only override the terms found, if there is only one

  1098  * term found. Any other and the found terms are used.

  1099  *

  1100  * The $args 'force_default' will force the term supplied as default to be

  1101  * assigned even if the object was not going to be termless

  1102  * @package WordPress

  1103  * @subpackage Taxonomy

  1104  * @since 2.3.0

  1105  *

  1106  * @uses $wpdb

  1107  * @uses do_action() Calls both 'delete_term' and 'delete_$taxonomy' action

  1108  *	hooks, passing term object, term id. 'delete_term' gets an additional

  1109  *	parameter with the $taxonomy parameter.

  1110  *

  1111  * @param int $term Term ID

  1112  * @param string $taxonomy Taxonomy Name

  1113  * @param array|string $args Optional. Change 'default' term id and override found term ids.

  1114  * @return bool|WP_Error Returns false if not term; true if completes delete action.

  1115  */

  1116 function wp_delete_term( $term, $taxonomy, $args = array() ) {

  1117 	global $wpdb;

  1118 

  1119 	$term = (int) $term;

  1120 

  1121 	if ( ! $ids = is_term($term, $taxonomy) )

  1122 		return false;

  1123 	if ( is_wp_error( $ids ) )

  1124 		return $ids;

  1125 

  1126 	$tt_id = $ids['term_taxonomy_id'];

  1127 

  1128 	$defaults = array();

  1129 	$args = wp_parse_args($args, $defaults);

  1130 	extract($args, EXTR_SKIP);

  1131 

  1132 	if ( isset($default) ) {

  1133 		$default = (int) $default;

  1134 		if ( ! is_term($default, $taxonomy) )

  1135 			unset($default);