Displays or retrieves the HTML dropdown list of categories.

The ‘hierarchical’ argument, which is disabled by default, will override the depth argument, unless it is true. When the argument is false, it will display all of the categories. When it is enabled it will use the value in the ‘depth’ argument.

$args array|string Optional

Array or string of arguments to generate a categories drop-down element. See WP_Term_Query::__construct() for information on additional accepted arguments.

• show_option_allstring
  Text to display for showing all categories.
• show_option_nonestring
  Text to display for showing no categories.
• option_none_valuestring
  Value to use when no category is selected.
• orderbystring
  Which column to use for ordering categories. See get_terms() for a list of accepted values. Default 'id' (term_id).
• pad_countsbool
  See get_terms() for an argument description. Default false.
• show_countbool|int
  Whether to include post counts. Accepts 0, 1, or their bool equivalents.
  Default 0.
• echobool|int
  Whether to echo or return the generated markup. Accepts 0, 1, or their bool equivalents. Default 1.
• hierarchicalbool|int
  Whether to traverse the taxonomy hierarchy. Accepts 0, 1, or their bool equivalents. Default 0.
• depthint
  Maximum depth. Default 0.
• tab_indexint
  Tab index for the select element. Default 0 (no tabindex).
• namestring
  Value for the 'name' attribute of the select element. Default 'cat'.
• idstring
  Value for the 'id' attribute of the select element. Defaults to the value of $name.
• classstring
  Value for the 'class' attribute of the select element. Default 'postform'.
• selectedint|string
  Value of the option that should be selected. Default 0.
• value_fieldstring
  Term field that should be used to populate the 'value' attribute of the option elements. Accepts any valid term field: 'term_id', 'name', 'slug', 'term_group', 'term_taxonomy_id', 'taxonomy', 'description', 'parent', 'count'. Default 'term_id'.
• taxonomystring|array
  Name of the taxonomy or taxonomies to retrieve. Default 'category'.
• hide_if_emptybool
  True to skip generating markup if no categories are found.
  Default false (create select element even if no categories are found).
• requiredbool
  Whether the <select> element should have the HTML5 'required' attribute.
  Default false.
• walkerWalker
  Walker object to use to build the output. Default empty which results in a Walker_CategoryDropdown instance being used.
• aria_describedbystring
  The 'id' of an element that contains descriptive text for the select.
  

More Arguments from WP_Term_Query::__construct( ... $query )

Array or query string of term query parameters.

• taxonomystring|string[]
  Taxonomy name, or array of taxonomy names, to which results should be limited.
• object_idsint|int[]
  Object ID, or array of object IDs. Results will be limited to terms associated with these objects.
• orderbystring
  Field(s) to order terms by. Accepts:
  

  • Term fields ('name', 'slug', 'term_group', 'term_id', 'id', 'description', 'parent', 'term_order'). Unless $object_ids is not empty, 'term_order' is treated the same as 'term_id'.
  • 'count' to use the number of objects associated with the term.
  • 'include' to match the 'order' of the $include param.
  • 'slug__in' to match the 'order' of the $slug param.
  • 'meta_value'
  • 'meta_value_num'.
  • The value of $meta_key.
  • The array keys of $meta_query.
  • 'none' to omit the ORDER BY clause.

  Default 'name'.
• orderstring
  Whether to order terms in ascending or descending order.
  Accepts 'ASC' (ascending) or 'DESC' (descending).
  Default 'ASC'.
• hide_emptybool|int
  Whether to hide terms not assigned to any posts. Accepts 1|true or 0|false. Default 1|true.
• includeint[]|string
  Array or comma/space-separated string of term IDs to include.
  Default empty array.
• excludeint[]|string
  Array or comma/space-separated string of term IDs to exclude.
  If $include is non-empty, $exclude is ignored.
  Default empty array.
• exclude_treeint[]|string
  Array or comma/space-separated string of term IDs to exclude along with all of their descendant terms. If $include is non-empty, $exclude_tree is ignored. Default empty array.
• numberint|string
  Maximum number of terms to return. Accepts ''|0 (all) or any positive number. Default ''|0 (all). Note that $number may not return accurate results when coupled with $object_ids.
  See #41796 for details.
• offsetint
  The number by which to offset the terms query.
• fieldsstring
  Term fields to query for. Accepts:
  

  • 'all' Returns an array of complete term objects (WP_Term[]).
  • 'all_with_object_id' Returns an array of term objects with the 'object_id' param (WP_Term[]). Works only when the $object_ids parameter is populated.
  • 'ids' Returns an array of term IDs (int[]).
  • 'tt_ids' Returns an array of term taxonomy IDs (int[]).
  • 'names' Returns an array of term names (string[]).
  • 'slugs' Returns an array of term slugs (string[]).
  • 'count' Returns the number of matching terms (int).
  • 'id=>parent' Returns an associative array of parent term IDs, keyed by term ID (int[]).
  • 'id=>name' Returns an associative array of term names, keyed by term ID (string[]).
  • 'id=>slug' Returns an associative array of term slugs, keyed by term ID (string[]).

  Default 'all'.
• countbool
  Whether to return a term count. If true, will take precedence over $fields. Default false.
• namestring|string[]
  Name or array of names to return term(s) for.
  
• slugstring|string[]
  Slug or array of slugs to return term(s) for.
  
• term_taxonomy_idint|int[]
  Term taxonomy ID, or array of term taxonomy IDs, to match when querying terms.
• hierarchicalbool
  Whether to include terms that have non-empty descendants (even if $hide_empty is set to true). Default true.
• searchstring
  Search criteria to match terms. Will be SQL-formatted with wildcards before and after.
• name__likestring
  Retrieve terms with criteria by which a term is LIKE $name__like.
• description__likestring
  Retrieve terms where the description is LIKE $description__like.
• pad_countsbool
  Whether to pad the quantity of a term's children in the quantity of each term's "count" object variable. Default false.
• getstring
  Whether to return terms regardless of ancestry or whether the terms are empty. Accepts 'all' or '' (disabled). Default ''.
• child_ofint
  Term ID to retrieve child terms of. If multiple taxonomies are passed, $child_of is ignored. Default 0.
• parentint
  Parent term ID to retrieve direct-child terms of.
  
• childlessbool
  True to limit results to terms that have no children.
  This parameter has no effect on non-hierarchical taxonomies.
  Default false.
• cache_domainstring
  Unique cache key to be produced when this query is stored in an object cache. Default 'core'.
• update_term_meta_cachebool
  Whether to prime meta caches for matched terms. Default true.
• meta_keystring|string[]
  Meta key or keys to filter by.
• meta_valuestring|string[]
  Meta value or values to filter by.
• meta_comparestring
  MySQL operator used for comparing the meta value.
  See WP_Meta_Query::__construct() for accepted values and default value.
• meta_compare_keystring
  MySQL operator used for comparing the meta key.
  See WP_Meta_Query::__construct() for accepted values and default value.
• meta_typestring
  MySQL data type that the meta_value column will be CAST to for comparisons.
  See WP_Meta_Query::__construct() for accepted values and default value.
• meta_type_keystring
  MySQL data type that the meta_key column will be CAST to for comparisons.
  See WP_Meta_Query::__construct() for accepted values and default value.
• meta_queryarray
  An associative array of WP_Meta_Query arguments.
  See WP_Meta_Query::__construct() for accepted values.

Default: ''

string HTML dropdown list of categories.

If you want to allow users to select multiple values, use wp_category_checklist() .

The wp_dropdown_cats filter is applied to the output string before it is echoed/returned.

File: wp-includes/category-template.php. View all references

function wp_dropdown_categories( $args = '' ) {
	$defaults = array(
		'show_option_all'   => '',
		'show_option_none'  => '',
		'orderby'           => 'id',
		'order'             => 'ASC',
		'show_count'        => 0,
		'hide_empty'        => 1,
		'child_of'          => 0,
		'exclude'           => '',
		'echo'              => 1,
		'selected'          => 0,
		'hierarchical'      => 0,
		'name'              => 'cat',
		'id'                => '',
		'class'             => 'postform',
		'depth'             => 0,
		'tab_index'         => 0,
		'taxonomy'          => 'category',
		'hide_if_empty'     => false,
		'option_none_value' => -1,
		'value_field'       => 'term_id',
		'required'          => false,
		'aria_describedby'  => '',
	);

	$defaults['selected'] = ( is_category() ) ? get_query_var( 'cat' ) : 0;

	// Back compat.
	if ( isset( $args['type'] ) && 'link' === $args['type'] ) {
		_deprecated_argument(
			__FUNCTION__,
			'3.0.0',
			sprintf(
				/* translators: 1: "type => link", 2: "taxonomy => link_category" */
				__( '%1$s is deprecated. Use %2$s instead.' ),
				'<code>type => link</code>',
				'<code>taxonomy => link_category</code>'
			)
		);
		$args['taxonomy'] = 'link_category';
	}

	// Parse incoming $args into an array and merge it with $defaults.
	$parsed_args = wp_parse_args( $args, $defaults );

	$option_none_value = $parsed_args['option_none_value'];

	if ( ! isset( $parsed_args['pad_counts'] ) && $parsed_args['show_count'] && $parsed_args['hierarchical'] ) {
		$parsed_args['pad_counts'] = true;
	}

	$tab_index = $parsed_args['tab_index'];

	$tab_index_attribute = '';
	if ( (int) $tab_index > 0 ) {
		$tab_index_attribute = " tabindex=\"$tab_index\"";
	}

	// Avoid clashes with the 'name' param of get_terms().
	$get_terms_args = $parsed_args;
	unset( $get_terms_args['name'] );
	$categories = get_terms( $get_terms_args );

	$name     = esc_attr( $parsed_args['name'] );
	$class    = esc_attr( $parsed_args['class'] );
	$id       = $parsed_args['id'] ? esc_attr( $parsed_args['id'] ) : $name;
	$required = $parsed_args['required'] ? 'required' : '';

	$aria_describedby_attribute = $parsed_args['aria_describedby'] ? ' aria-describedby="' . esc_attr( $parsed_args['aria_describedby'] ) . '"' : '';

	if ( ! $parsed_args['hide_if_empty'] || ! empty( $categories ) ) {
		$output = "<select $required name='$name' id='$id' class='$class'$tab_index_attribute$aria_describedby_attribute>\n";
	} else {
		$output = '';
	}
	if ( empty( $categories ) && ! $parsed_args['hide_if_empty'] && ! empty( $parsed_args['show_option_none'] ) ) {

		/**
		 * Filters a taxonomy drop-down display element.
		 *
		 * A variety of taxonomy drop-down display elements can be modified
		 * just prior to display via this filter. Filterable arguments include
		 * 'show_option_none', 'show_option_all', and various forms of the
		 * term name.
		 *
		 * @since 1.2.0
		 *
		 * @see wp_dropdown_categories()
		 *
		 * @param string       $element  Category name.
		 * @param WP_Term|null $category The category object, or null if there's no corresponding category.
		 */
		$show_option_none = apply_filters( 'list_cats', $parsed_args['show_option_none'], null );
		$output          .= "\t<option value='" . esc_attr( $option_none_value ) . "' selected='selected'>$show_option_none</option>\n";
	}

	if ( ! empty( $categories ) ) {

		if ( $parsed_args['show_option_all'] ) {

			/** This filter is documented in wp-includes/category-template.php */
			$show_option_all = apply_filters( 'list_cats', $parsed_args['show_option_all'], null );
			$selected        = ( '0' === (string) $parsed_args['selected'] ) ? " selected='selected'" : '';
			$output         .= "\t<option value='0'$selected>$show_option_all</option>\n";
		}

		if ( $parsed_args['show_option_none'] ) {

			/** This filter is documented in wp-includes/category-template.php */
			$show_option_none = apply_filters( 'list_cats', $parsed_args['show_option_none'], null );
			$selected         = selected( $option_none_value, $parsed_args['selected'], false );
			$output          .= "\t<option value='" . esc_attr( $option_none_value ) . "'$selected>$show_option_none</option>\n";
		}

		if ( $parsed_args['hierarchical'] ) {
			$depth = $parsed_args['depth'];  // Walk the full depth.
		} else {
			$depth = -1; // Flat.
		}
		$output .= walk_category_dropdown_tree( $categories, $depth, $parsed_args );
	}

	if ( ! $parsed_args['hide_if_empty'] || ! empty( $categories ) ) {
		$output .= "</select>\n";
	}

	/**
	 * Filters the taxonomy drop-down output.
	 *
	 * @since 2.1.0
	 *
	 * @param string $output      HTML output.
	 * @param array  $parsed_args Arguments used to build the drop-down.
	 */
	$output = apply_filters( 'wp_dropdown_cats', $output, $parsed_args );

	if ( $parsed_args['echo'] ) {
		echo $output;
	}

	return $output;
}