<?php

/**

 * Taxonomy API: Core category-specific template tags

 *

 * @package WordPress

 * @subpackage Template

 * @since 1.2.0

 */

/**

 * 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 );

	if ( is_wp_error( $category ) ) {

		return '';

	}

	return $category;

}

/**

 * Retrieve category parents with separator.

 *

 * @since 1.2.0

 * @since 4.8.0 The `$visited` parameter was deprecated and renamed to `$deprecated`.

 *

 * @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 $deprecated Not used.

 * @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, $deprecated = array() ) {

	if ( ! empty( $deprecated ) ) {

		_deprecated_argument( __FUNCTION__, '4.8.0' );

	}

	$format = $nicename ? 'slug' : 'name';

	$args = array(

		'separator' => $separator,

		'link'      => $link,

		'format'    => $format,

	);

	return get_term_parents_list( $id, 'category', $args );

}

/**

 * Retrieve post categories.

 *

 * This tag may be used outside The Loop by passing a post id as the parameter.

 *

 * Note: This function only returns results from the default "category" taxonomy.

 * For custom taxonomies use get_the_terms().

 *

 * @since 0.71

 *

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

 * @return WP_Term[] Array of WP_Term objects, one for each category assigned to the post.

 */

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 ] );

	}

	/**

	 * Filters the array of categories to return for a post.

	 *

	 * @since 3.1.0

	 * @since 4.4.0 Added `$id` parameter.

	 *

	 * @param WP_Term[] $categories An array of categories to return for the post.

	 * @param int|false $id         ID of the post.

	 */

	return apply_filters( 'get_the_categories', $categories, $id );

}

/**

 * 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 );

	if ( is_wp_error( $category ) ) {

		return $category;

	}

	return ( $category ) ? $category->name : '';

}

/**

 * Retrieve category list for a post in either HTML list or custom format.

 *

 * @since 1.5.1

 *

 * @global WP_Rewrite $wp_rewrite

 *

 * @param string $separator Optional. Separator between the categories. By default, the links are placed

 *                          in an unordered list. An empty string will result in the default behavior.

 * @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;

	if ( ! is_object_in_taxonomy( get_post_type( $post_id ), 'category' ) ) {

		/** This filter is documented in wp-includes/category-template.php */

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

	}

	/**

	 * Filters the categories before building the category list.

	 *

	 * @since 4.4.0

	 *

	 * @param WP_Term[] $categories An array of the post's categories.

	 * @param int|bool  $post_id    ID of the post we're retrieving categories for. When `false`, we assume the

	 *                              current post in the loop.

	 */

	$categories = apply_filters( 'the_category_list', get_the_category( $post_id ), $post_id );

	if ( empty( $categories ) ) {

		/** This filter is documented in wp-includes/category-template.php */

		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 );

					}

					$thelist .= '<a href="' . esc_url( get_category_link( $category->term_id ) ) . '" ' . $rel . '>' . $category->name . '</a></li>';

					break;

				case 'single':

					$thelist .= '<a href="' . esc_url( get_category_link( $category->term_id ) ) . '"  ' . $rel . '>';

					if ( $category->parent ) {

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

					}

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

					break;

				case '':

				default:

					$thelist .= '<a href="' . esc_url( get_category_link( $category->term_id ) ) . '" ' . $rel . '>' . $category->name . '</a></li>';

			}

		}

		$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 );

					}

					$thelist .= '<a href="' . esc_url( get_category_link( $category->term_id ) ) . '" ' . $rel . '>' . $category->name . '</a>';

					break;

				case 'single':

					$thelist .= '<a href="' . esc_url( get_category_link( $category->term_id ) ) . '" ' . $rel . '>';

					if ( $category->parent ) {

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

					}

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

					break;

				case '':

				default:

					$thelist .= '<a href="' . esc_url( get_category_link( $category->term_id ) ) . '" ' . $rel . '>' . $category->name . '</a>';

			}

			++$i;

		}

	}

	/**

	 * Filters the category or list of categories.

	 *

	 * @since 1.2.0

	 *

	 * @param string $thelist   List of categories for the current post.

	 * @param string $separator Separator used between the categories.

	 * @param string $parents   How to display the category parents. Accepts 'multiple',

	 *                          'single', or empty.

	 */

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

}

/**

 * Checks if the current post is 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.

 *

 * For more information on this and similar theme functions, check out

 * the {@link https://developer.wordpress.org/themes/basics/conditional-tags/

 * Conditional Tags} article in the Theme Developer Handbook.

 *

 * @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 category list for a post in either HTML list or custom format.

 *

 * @since 0.71

 *

 * @param string $separator Optional. Separator between the categories. By default, the links are placed

 *                          in an unordered list. An empty string will result in the default behavior.

 * @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 );

}

/**

 * 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

 * @since 4.2.0 Introduced the `value_field` argument.

 * @since 4.6.0 Introduced the `required` argument.

 *

 * @param string|array $args {

 *     Optional. Array or string of arguments to generate a categories drop-down element. See WP_Term_Query::__construct()

 *     for information on additional accepted arguments.

 *

 *     @type string       $show_option_all   Text to display for showing all categories. Default empty.

 *     @type string       $show_option_none  Text to display for showing no categories. Default empty.

 *     @type string       $option_none_value Value to use when no category is selected. Default empty.

 *     @type string       $orderby           Which column to use for ordering categories. See get_terms() for a list

 *                                           of accepted values. Default 'id' (term_id).

 *     @type bool         $pad_counts        See get_terms() for an argument description. Default false.

 *     @type bool|int     $show_count        Whether to include post counts. Accepts 0, 1, or their bool equivalents.

 *                                           Default 0.

 *     @type bool|int     $echo              Whether to echo or return the generated markup. Accepts 0, 1, or their

 *                                           bool equivalents. Default 1.

 *     @type bool|int     $hierarchical      Whether to traverse the taxonomy hierarchy. Accepts 0, 1, or their bool

 *                                           equivalents. Default 0.

 *     @type int          $depth             Maximum depth. Default 0.

 *     @type int          $tab_index         Tab index for the select element. Default 0 (no tabindex).

 *     @type string       $name              Value for the 'name' attribute of the select element. Default 'cat'.

 *     @type string       $id                Value for the 'id' attribute of the select element. Defaults to the value

 *                                           of `$name`.

 *     @type string       $class             Value for the 'class' attribute of the select element. Default 'postform'.

 *     @type int|string   $selected          Value of the option that should be selected. Default 0.

 *     @type string       $value_field       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'.

 *     @type string|array $taxonomy          Name of the category or categories to retrieve. Default 'category'.

 *     @type bool         $hide_if_empty     True to skip generating markup if no categories are found.

 *                                           Default false (create select element even if no categories are found).

 *     @type bool         $required          Whether the `<select>` element should have the HTML5 'required' attribute.

 *                                           Default false.

 * }

 * @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',

		'hide_if_empty'     => false,

		'option_none_value' => -1,

		'value_field'       => 'term_id',

		'required'          => false,

	);

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

	// Back compat.

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

		_deprecated_argument(

			__FUNCTION__,

			'3.0.0',

			/* translators: 1: "type => link", 2: "taxonomy => link_category" */

			sprintf(

				__( '%1$s is deprecated. Use %2$s instead.' ),

				'<code>type => link</code>',

				'<code>taxonomy => link_category</code>'

			)

		);

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

	}

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

	$option_none_value = $r['option_none_value'];

	if ( ! isset( $r['pad_counts'] ) && $r['show_count'] && $r['hierarchical'] ) {

		$r['pad_counts'] = true;

	}

	$tab_index = $r['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 = $r;

	unset( $get_terms_args['name'] );

	$categories = get_terms( $r['taxonomy'], $get_terms_args );

	$name     = esc_attr( $r['name'] );

	$class    = esc_attr( $r['class'] );

	$id       = $r['id'] ? esc_attr( $r['id'] ) : $name;

	$required = $r['required'] ? 'required' : '';

	if ( ! $r['hide_if_empty'] || ! empty( $categories ) ) {

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

	} else {

		$output = '';

	}

	if ( empty( $categories ) && ! $r['hide_if_empty'] && ! empty( $r['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', $r['show_option_none'], null );

		$output          .= "\t<option value='" . esc_attr( $option_none_value ) . "' selected='selected'>$show_option_none</option>\n";