<?php

/**

 * Category Template Tags and API.

 *

 * @package WordPress

 * @subpackage Template

 */

/**

 * Retrieve category link URL.

 *

 * @since 1.0.0

 * @see get_term_link()

 *

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

 * @return string Link on success, empty string if category does not exist.

 */

function get_category_link( $category ) {

	if ( ! is_object( $category ) )

		$category = (int) $category;

	$category = get_term_link( $category, 'category' );

	if ( is_wp_error( $category ) )

		return '';

	return $category;

}

/**

 * Retrieve category parents with separator.

 *

 * @since 1.2.0

 *

 * @param int $id Category ID.

 * @param bool $link Optional, default is false. Whether to format with link.

 * @param string $separator Optional, default is '/'. How to separate categories.

 * @param bool $nicename Optional, default is false. Whether to use nice name for display.

 * @param array $visited Optional. Already linked to categories to prevent duplicates.

 * @return string|WP_Error A list of category parents on success, WP_Error on failure.

 */

function get_category_parents( $id, $link = false, $separator = '/', $nicename = false, $visited = array() ) {

	$chain = '';

	$parent = get_term( $id, 'category' );

	if ( is_wp_error( $parent ) )

		return $parent;

	if ( $nicename )

		$name = $parent->slug;

	else

		$name = $parent->name;

	if ( $parent->parent && ( $parent->parent != $parent->term_id ) && !in_array( $parent->parent, $visited ) ) {

		$visited[] = $parent->parent;

		$chain .= get_category_parents( $parent->parent, $link, $separator, $nicename, $visited );

	}

	if ( $link )

	else

		$chain .= $name.$separator;

	return $chain;

}

/**

 * Retrieve post categories.

 *

 * @since 0.71

 *

 * @param int $id Optional, default to current post ID. The post ID.

 * @return array

 */

function get_the_category( $id = false ) {

	$categories = get_the_terms( $id, 'category' );

	if ( ! $categories || is_wp_error( $categories ) )

		$categories = array();

	$categories = array_values( $categories );

	foreach ( array_keys( $categories ) as $key ) {

		_make_cat_compat( $categories[$key] );

	}

	return apply_filters( 'get_the_categories', $categories );

}

/**

 * Sort categories by name.

 *

 * Used by usort() as a callback, should not be used directly. Can actually be

 * used to sort any term object.

 *

 * @since 2.3.0

 * @access private

 *

 * @param object $a

 * @param object $b

 * @return int

 */

function _usort_terms_by_name( $a, $b ) {

	return strcmp( $a->name, $b->name );

}

/**

 * Sort categories by ID.

 *

 * Used by usort() as a callback, should not be used directly. Can actually be

 * used to sort any term object.

 *

 * @since 2.3.0

 * @access private

 *

 * @param object $a

 * @param object $b

 * @return int

 */

function _usort_terms_by_ID( $a, $b ) {

	if ( $a->term_id > $b->term_id )

		return 1;

	elseif ( $a->term_id < $b->term_id )

		return -1;

	else

		return 0;

}

/**

 * Retrieve category name based on category ID.

 *

 * @since 0.71

 *

 * @param int $cat_ID Category ID.

 * @return string|WP_Error Category name on success, WP_Error on failure.

 */

function get_the_category_by_ID( $cat_ID ) {

	$cat_ID = (int) $cat_ID;

	$category = get_term( $cat_ID, 'category' );

	if ( is_wp_error( $category ) )

		return $category;

}

/**

 * Retrieve category list in either HTML list or custom format.

 *

 * @since 1.5.1

 *

 * @param string $separator Optional, default is empty string. Separator for between the categories.

 * @param string $parents Optional. How to display the parents.

 * @param int $post_id Optional. Post ID to retrieve categories.

 * @return string

 */

function get_the_category_list( $separator = '', $parents='', $post_id = false ) {

	global $wp_rewrite;

		return apply_filters( 'the_category', '', $separator, $parents );

	$categories = get_the_category( $post_id );

		return apply_filters( 'the_category', __( 'Uncategorized' ), $separator, $parents );

	$rel = ( is_object( $wp_rewrite ) && $wp_rewrite->using_permalinks() ) ? 'rel="category tag"' : 'rel="category"';

	$thelist = '';

	if ( '' == $separator ) {

		$thelist .= '<ul class="post-categories">';

		foreach ( $categories as $category ) {

			$thelist .= "\n\t<li>";

			switch ( strtolower( $parents ) ) {

				case 'multiple':

					if ( $category->parent )

						$thelist .= get_category_parents( $category->parent, true, $separator );

					break;

				case 'single':

					if ( $category->parent )

						$thelist .= get_category_parents( $category->parent, false, $separator );

					$thelist .= $category->name.'</a></li>';

					break;

				case '':

				default:

			}

		}

		$thelist .= '</ul>';

	} else {

		$i = 0;

		foreach ( $categories as $category ) {

			if ( 0 < $i )

				$thelist .= $separator;

			switch ( strtolower( $parents ) ) {

				case 'multiple':

					if ( $category->parent )

						$thelist .= get_category_parents( $category->parent, true, $separator );

					break;

				case 'single':

					if ( $category->parent )

						$thelist .= get_category_parents( $category->parent, false, $separator );

					$thelist .= "$category->name</a>";

					break;

				case '':

				default:

			}

			++$i;

		}

	}

	return apply_filters( 'the_category', $thelist, $separator, $parents );

}

/**

 * Check if the current post in within any of the given categories.

 *

 * The given categories are checked against the post's categories' term_ids, names and slugs.

 * Categories given as integers will only be checked against the post's categories' term_ids.

 *

 * Prior to v2.5 of WordPress, category names were not supported.

 * Prior to v2.7, category slugs were not supported.

 * Prior to v2.7, only one category could be compared: in_category( $single_category ).

 * Prior to v2.7, this function could only be used in the WordPress Loop.

 * As of 2.7, the function can be used anywhere if it is provided a post ID or post object.

 *

 * @since 1.2.0

 *

 * @param int|string|array $category Category ID, name or slug, or array of said.

 * @param int|object $post Optional. Post to check instead of the current post. (since 2.7.0)

 * @return bool True if the current post is in any of the given categories.

 */

function in_category( $category, $post = null ) {

	if ( empty( $category ) )

		return false;

	return has_category( $category, $post );

}

/**

 * Display the category list for the post.

 *

 * @since 0.71

 *

 * @param string $separator Optional, default is empty string. Separator for between the categories.

 * @param string $parents Optional. How to display the parents.

 * @param int $post_id Optional. Post ID to retrieve categories.

 */

function the_category( $separator = '', $parents='', $post_id = false ) {

	echo get_the_category_list( $separator, $parents, $post_id );

}

/**

 * Retrieve category description.

 *

 * @since 1.0.0

 *

 * @param int $category Optional. Category ID. Will use global category ID by default.

 * @return string Category description, available.

 */

function category_description( $category = 0 ) {

	return term_description( $category, 'category' );

}

/**

 * Display or retrieve 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.

 *

 * @since 2.1.0

 *

 * @return string HTML content only if 'echo' argument is 0.

 */

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',

	);

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

	// Back compat.

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

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

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

	}

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

		$r['pad_counts'] = true;

	}

	$tab_index_attribute = '';

		$tab_index_attribute = " tabindex=\"$tab_index\"";

		$output = "<select name='$name' id='$id' class='$class' $tab_index_attribute>\n";

		$output = '';

	}

	if ( ! empty( $categories ) ) {

			$selected = ( '0' === strval($r['selected']) ) ? " selected='selected'" : '';

			$output .= "\t<option value='0'$selected>$show_option_all</option>\n";

		}