<?php

/**

 * WordPress Category API

 *

 * @package WordPress

 */

/**

 * Retrieves all category IDs.

 *

 * @since 2.0.0

 * @link http://codex.wordpress.org/Function_Reference/get_all_category_ids

 *

 * @return object List of all of the category IDs.

 */

function get_all_category_ids() {

	if ( ! $cat_ids = wp_cache_get( 'all_category_ids', 'category' ) ) {

		$cat_ids = get_terms( 'category', array('fields' => 'ids', 'get' => 'all') );

		wp_cache_add( 'all_category_ids', $cat_ids, 'category' );

	}

	return $cat_ids;

}

/**

 * Retrieve list of category objects.

 *

 * If you change the type to 'link' in the arguments, then the link categories

 * will be returned instead. Also all categories will be updated to be backwards

 * compatible with pre-2.3 plugins and themes.

 *

 * @since 2.1.0

 * @see get_terms() Type of arguments that can be changed.

 * @link http://codex.wordpress.org/Function_Reference/get_categories

 *

 * @param string|array $args Optional. Change the defaults retrieving categories.

 * @return array List of categories.

 */

	$defaults = array( 'taxonomy' => 'category' );

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

	$taxonomy = apply_filters( 'get_categories_taxonomy', $args['taxonomy'], $args );

	// Back compat

	if ( isset($args['type']) && 'link' == $args['type'] ) {

		_deprecated_argument( __FUNCTION__, '3.0', '' );

		$taxonomy = $args['taxonomy'] = 'link_category';

	}

	$categories = (array) get_terms( $taxonomy, $args );

	foreach ( array_keys( $categories ) as $k )

		_make_cat_compat( $categories[$k] );

	return $categories;

}

/**

 * Retrieves category data given a category ID or category object.

 *

 * If you pass the $category parameter an object, which is assumed to be the

 * category row object retrieved the database. It will cache the category data.

 *

 * If you pass $category an integer of the category ID, then that category will

 * be retrieved from the database, if it isn't already cached, and pass it back.

 *

 * If you look at get_term(), then both types will be passed through several

 * filters and finally sanitized based on the $filter parameter value.

 *

 * The category will converted to maintain backwards compatibility.

 *

 * @since 1.5.1

 * @uses get_term() Used to get the category data from the taxonomy.

 *

 * @param int|object $category Category ID or Category row object

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

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

 * @return mixed Category data in type defined by $output parameter.

 */

	$category = get_term( $category, 'category', $output, $filter );

	if ( is_wp_error( $category ) )

		return $category;

	_make_cat_compat( $category );

	return $category;

}

/**

 * Retrieve category based on URL containing the category slug.

 *

 * Breaks the $category_path parameter up to get the category slug.

 *

 * Tries to find the child path and will return it. If it doesn't find a

 * match, then it will return the first category matching slug, if $full_match,

 * is set to false. If it does not, then it will return null.

 *

 * It is also possible that it will return a WP_Error object on failure. Check

 * for it when using this function.

 *

 * @since 2.1.0

 *

 * @param string $category_path URL containing category slugs.

 * @param bool $full_match Optional. Whether full path should be matched.

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

 * @return null|object|array Null on failure. Type is based on $output value.

 */

function get_category_by_path( $category_path, $full_match = true, $output = OBJECT ) {

	$category_path = rawurlencode( urldecode( $category_path ) );

	$category_path = str_replace( '%2F', '/', $category_path );

	$category_path = str_replace( '%20', ' ', $category_path );

	$category_paths = '/' . trim( $category_path, '/' );

	$leaf_path  = sanitize_title( basename( $category_paths ) );

	$category_paths = explode( '/', $category_paths );

	$full_path = '';

	foreach ( (array) $category_paths as $pathdir )

		$full_path .= ( $pathdir != '' ? '/' : '' ) . sanitize_title( $pathdir );

	$categories = get_terms( 'category', array('get' => 'all', 'slug' => $leaf_path) );

	if ( empty( $categories ) )

		return null;

	foreach ( $categories as $category ) {

		$path = '/' . $leaf_path;

		$curcategory = $category;

		while ( ( $curcategory->parent != 0 ) && ( $curcategory->parent != $curcategory->term_id ) ) {

			$curcategory = get_term( $curcategory->parent, 'category' );

			if ( is_wp_error( $curcategory ) )

				return $curcategory;

			$path = '/' . $curcategory->slug . $path;

		}

		if ( $path == $full_path )

			return get_category( $category->term_id, $output );

	}

	// If full matching is not required, return the first cat that matches the leaf.

	if ( ! $full_match )

		return get_category( $categories[0]->term_id, $output );

	return null;

}

/**

 * Retrieve category object by category slug.

 *

 * @since 2.3.0

 *

 * @param string $slug The category slug.

 * @return object Category data object

 */

function get_category_by_slug( $slug  ) {

	$category = get_term_by( 'slug', $slug, 'category' );

	if ( $category )

		_make_cat_compat( $category );

	return $category;

}

/**

 * Retrieve the ID of a category from its name.

 *

 * @since 1.0.0

 *

 * @return int 0, if failure and ID of category on success.

 */

	$cat = get_term_by( 'name', $cat_name, 'category' );

	if ( $cat )

		return $cat->term_id;

	return 0;

}

/**

 * Retrieve the name of a category from its ID.

 *

 * @since 1.0.0

 *

 * @param int $cat_id Category ID

 * @return string Category name, or an empty string if category doesn't exist.

 */

function get_cat_name( $cat_id ) {

	$cat_id = (int) $cat_id;

	if ( ! $category || is_wp_error( $category ) )

		return '';

	return $category->name;

}

/**

 * Check if a category is an ancestor of another category.

 *

 * You can use either an id or the category object for both parameters. If you

 * use an integer the category will be retrieved.

 *

 * @since 2.1.0

 *

 * @param int|object $cat1 ID or object to check if this is the parent category.

 * @param int|object $cat2 The child category.

 * @return bool Whether $cat2 is child of $cat1

 */

function cat_is_ancestor_of( $cat1, $cat2 ) {

	return term_is_ancestor_of( $cat1, $cat2, 'category' );

}

/**

 * Sanitizes category data based on context.

 *

 * @since 2.3.0

 * @uses sanitize_term() See this function for what context are supported.

 *

 * @param object|array $category Category data

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

 * @return object|array Same type as $category with sanitized data for safe use.

 */

function sanitize_category( $category, $context = 'display' ) {

	return sanitize_term( $category, 'category', $context );

}

/**

 * Sanitizes data in single category key field.

 *

 * @since 2.3.0

 * @uses sanitize_term_field() See function for more details.

 *

 * @param string $field Category key to sanitize

 * @param mixed $value Category value to sanitize

 * @param int $cat_id Category ID

 * @param string $context What filter to use, 'raw', 'display', etc.

 * @return mixed Same type as $value after $value has been sanitized.

 */

function sanitize_category_field( $field, $value, $cat_id, $context ) {

	return sanitize_term_field( $field, $value, $cat_id, 'category', $context );

}

/* Tags */

/**

 * Retrieves all post tags.

 *

 * @since 2.3.0

 * @see get_terms() For list of arguments to pass.

 * @uses apply_filters() Calls 'get_tags' hook on array of tags and with $args.

 *

 * @param string|array $args Tag arguments to use when retrieving tags.

 * @return array List of tags.

 */

	$tags = get_terms( 'post_tag', $args );

	if ( empty( $tags ) ) {

		$return = array();

		return $return;

	}

	$tags = apply_filters( 'get_tags', $tags, $args );

	return $tags;

}

/**

 * Retrieve post tag by tag ID or tag object.

 *

 * If you pass the $tag parameter an object, which is assumed to be the tag row

 * object retrieved the database. It will cache the tag data.

 *

 * If you pass $tag an integer of the tag ID, then that tag will

 * be retrieved from the database, if it isn't already cached, and pass it back.

 *

 * If you look at get_term(), then both types will be passed through several

 * filters and finally sanitized based on the $filter parameter value.

 *

 * @since 2.3.0

 *

 * @param int|object $tag

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

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

 * @return object|array Return type based on $output value.

 */

	return get_term( $tag, 'post_tag', $output, $filter );

}

/* Cache */

/**

 * Remove the category cache data based on ID.

 *

 * @since 2.1.0

 * @uses clean_term_cache() Clears the cache for the category based on ID

 *

 * @param int $id Category ID

 */

function clean_category_cache( $id ) {

	clean_term_cache( $id, 'category' );

}

/**

 * Update category structure to old pre 2.3 from new taxonomy structure.

 *

 * This function was added for the taxonomy support to update the new category

 * structure with the old category one. This will maintain compatibility with

 * plugins and themes which depend on the old key or property names.

 *

 * The parameter should only be passed a variable and not create the array or

 * object inline to the parameter. The reason for this is that parameter is

 * passed by reference and PHP will fail unless it has the variable.

 *

 * There is no return value, because everything is updated on the variable you

 * pass to it. This is one of the features with using pass by reference in PHP.

 *

 * @since 2.3.0

 * @access private

 *

 * @param array|object $category Category Row object or array

 */

function _make_cat_compat( &$category ) {

	if ( is_object( $category ) ) {

		$category->cat_ID = &$category->term_id;

		$category->category_count = &$category->count;

		$category->category_description = &$category->description;

		$category->cat_name = &$category->name;

		$category->category_nicename = &$category->slug;

		$category->category_parent = &$category->parent;

	} elseif ( is_array( $category ) && isset( $category['term_id'] ) ) {

		$category['cat_ID'] = &$category['term_id'];

		$category['category_count'] = &$category['count'];

		$category['category_description'] = &$category['description'];

		$category['cat_name'] = &$category['name'];

		$category['category_nicename'] = &$category['slug'];

		$category['category_parent'] = &$category['parent'];

	}

}