Rahmon · June 21, 2023 11:43
diff --git a/get_post_categories.php b/get_post_categories.php
 <?php
 /**
 * Get the post categories preserving the hierarchical order
 *
 * This function returns an array with the following structure
 *
 * [
 *      [parent_term_id] => [
 *          [children] => [
 *              [child_term_id] => [
 *                  [children] => [
 *                      [...]
 *                  ],
 *                  [name]     => 'child_term_name',
 *              ],
 *          ],
 *	    [name] => 'parent_term_name
 *      ]
 *      [...]
 * ]
 *
 * @author Ramon Ahnert <https://profiles.wordpress.org/rahmohn/>, Felipe Elia <https://profiles.wordpress.org/felipeelia/>
 * @param int $post_id The post ID
 * @return array
 */
 function get_post_categories( $post_id ) {
 	$categories    = wp_list_sort( get_the_category( $post_id ), 'term_id' );
 	$transient_key = 'post-' . $post_id . '-categories-tree';

 	if ( empty( $categories ) ) {
 		delete_transient( $transient_key );

 		return [];
 	}

 	/**
 	 * Return an array with term_id, name and parent
 	 *
 	 * @param WP_Term $category
 	 * @return array
 	 */
 	$map_termid_name_parent = function ( $category ) {
 		return [
 			'term_id' => $category->term_id,
 			'name'    => $category->name,
 			'parent'  => $category->parent,
 		];
 	};

 	$cached_categories = get_transient( $transient_key );

 	// If categories don't changed, we'll return a cached value.
 	if (
 		false !== $cached_categories &&
 		is_array( $cached_categories ) &&
 		! empty( $cached_categories['categories_tree'] ) &&
 		! empty( $cached_categories['term_id_name_parent_json'] )
 	) {
 		// We rely on term_id, name and parent to check if categories have changed
 		$categories_termid_name_parent_json = wp_json_encode( array_map( $map_termid_name_parent, $categories ) );

 		if ( $categories_termid_name_parent_json === $cached_categories['term_id_name_parent_json'] ) {
 			return $cached_categories['categories_tree'];
 		}
 	}

 	/**
 	 * Build the category tree
 	 *
 	 * This function returns an array with the following structure
 	 *
 	 * [
 	 *      [parent_term_id] => [
 	 *          [children] => [
 	 *              [child_term_id] => [
 	 *                  [name]     => 'child_term_name',
 	 *                  [children] => [
 	 *                      [...]
 	 *                  ]
 	 *              ]
 	 *          ]
 	 *      ]
 	 *      [...]
 	 * ]
 	 *
 	 * @param array   $categories_tree  Array used to hold the categories (passed by reference)
 	 * @param WP_Term $child_category   Child category
 	 * @param array   $ancestors        The ancestors ids of child category from highest to lowest in the hierarchy
 	 * @param integer $key              Position in the hierarchy of ancestors
 	 * @param integer $depth_level      Check how depth we are to avoid an infinite loop
 	 * @return void
 	 */
 	$build_category_tree = function ( &$categories_tree, $child_category, $ancestors, $key = 0, $depth_level = 0 ) use ( &$build_category_tree ) {
 		$count = count( $ancestors );

 		if ( $key < $count && 200 > $depth_level ) {
 			// If the category is not on the category tree, add it.
 			if ( ! array_key_exists( $ancestors[ $key ], $categories_tree ) ) {
 				$categories_tree[ $ancestors[ $key ] ]['children'] = [];
 			}

 			// Fill with child category name
 			if ( $ancestors[ $key ] === $child_category->parent ) {
 				$categories_tree[ $ancestors[ $key ] ]['children'][ $child_category->term_id ]['name'] = $child_category->name;
 			}

 			// Go to the next level of hierarchy
 			$build_category_tree( $categories_tree[ $ancestors[ $key ] ]['children'], $child_category, $ancestors, $key + 1, $depth_level + 1 );
 		}

 	};

 	$categories_tree = [];
 	// Build the category tree with all levels
 	foreach ( $categories as $category ) {
 		// Fill the category tree with the information of root categories
 		if ( 0 === $category->parent ) {
 			$categories_tree[ $category->term_id ]['name'] = $category->name;
 			continue;
 		}

 		$ancestors = array_reverse( get_ancestors( $category->term_id, 'category', 'taxonomy' ) );

 		$build_category_tree( $categories_tree, $category, $ancestors );
 	}

 	// Rely on term_id, name and parent to verify if categories have changed
 	$categories_termid_name_parent = array_map( $map_termid_name_parent, $categories );

 	set_transient(
 		$transient_key,
 		[
 			'term_id_name_parent_json' => wp_json_encode( $categories_termid_name_parent ),
 			'categories_tree'          => $categories_tree,
 		]
 	);

 	return $categories_tree;
 }

 // print_r( get_post_categories( $YOUR_POST_ID ) );
	<?php
	/**
	* Get the post categories preserving the hierarchical order
	*
	* This function returns an array with the following structure
	*
	* [
	* [parent_term_id] => [
	* [children] => [
	* [child_term_id] => [
	* [children] => [
	* [...]
	* ],
	* [name] => 'child_term_name',
	* ],
	* ],
	* [name] => 'parent_term_name
	* ]
	* [...]
	* ]
	*
	* @author Ramon Ahnert <https://profiles.wordpress.org/rahmohn/>, Felipe Elia <https://profiles.wordpress.org/felipeelia/>
	* @param int $post_id The post ID
	* @return array
	*/
	function get_post_categories( $post_id ) {
	$categories = wp_list_sort( get_the_category( $post_id ), 'term_id' );
	$transient_key = 'post-' . $post_id . '-categories-tree';

	if ( empty( $categories ) ) {
	delete_transient( $transient_key );

	return [];
	}

	/**
	* Return an array with term_id, name and parent
	*
	* @param WP_Term $category
	* @return array
	*/
	$map_termid_name_parent = function ( $category ) {
	return [
	'term_id' => $category->term_id,
	'name' => $category->name,
	'parent' => $category->parent,
	];
	};

	$cached_categories = get_transient( $transient_key );

	// If categories don't changed, we'll return a cached value.
	if (
	false !== $cached_categories &&
	is_array( $cached_categories ) &&
	! empty( $cached_categories['categories_tree'] ) &&
	! empty( $cached_categories['term_id_name_parent_json'] )
	) {
	// We rely on term_id, name and parent to check if categories have changed
	$categories_termid_name_parent_json = wp_json_encode( array_map( $map_termid_name_parent, $categories ) );

	if ( $categories_termid_name_parent_json === $cached_categories['term_id_name_parent_json'] ) {
	return $cached_categories['categories_tree'];
	}
	}

	/**
	* Build the category tree
	*
	* This function returns an array with the following structure
	*
	* [
	* [parent_term_id] => [
	* [children] => [
	* [child_term_id] => [
	* [name] => 'child_term_name',
	* [children] => [
	* [...]
	* ]
	* ]
	* ]
	* ]
	* [...]
	* ]
	*
	* @param array $categories_tree Array used to hold the categories (passed by reference)
	* @param WP_Term $child_category Child category
	* @param array $ancestors The ancestors ids of child category from highest to lowest in the hierarchy
	* @param integer $key Position in the hierarchy of ancestors
	* @param integer $depth_level Check how depth we are to avoid an infinite loop
	* @return void
	*/
	$build_category_tree = function ( &$categories_tree, $child_category, $ancestors, $key = 0, $depth_level = 0 ) use ( &$build_category_tree ) {
	$count = count( $ancestors );

	if ( $key < $count && 200 > $depth_level ) {
	// If the category is not on the category tree, add it.
	if ( ! array_key_exists( $ancestors[ $key ], $categories_tree ) ) {
	$categories_tree[ $ancestors[ $key ] ]['children'] = [];
	}

	// Fill with child category name
	if ( $ancestors[ $key ] === $child_category->parent ) {
	$categories_tree[ $ancestors[ $key ] ]['children'][ $child_category->term_id ]['name'] = $child_category->name;
	}

	// Go to the next level of hierarchy
	$build_category_tree( $categories_tree[ $ancestors[ $key ] ]['children'], $child_category, $ancestors, $key + 1, $depth_level + 1 );
	}

	};

	$categories_tree = [];
	// Build the category tree with all levels
	foreach ( $categories as $category ) {
	// Fill the category tree with the information of root categories
	if ( 0 === $category->parent ) {
	$categories_tree[ $category->term_id ]['name'] = $category->name;
	continue;
	}

	$ancestors = array_reverse( get_ancestors( $category->term_id, 'category', 'taxonomy' ) );

	$build_category_tree( $categories_tree, $category, $ancestors );
	}

	// Rely on term_id, name and parent to verify if categories have changed
	$categories_termid_name_parent = array_map( $map_termid_name_parent, $categories );

	set_transient(
	$transient_key,
	[
	'term_id_name_parent_json' => wp_json_encode( $categories_termid_name_parent ),
	'categories_tree' => $categories_tree,
	]
	);

	return $categories_tree;
	}

	// print_r( get_post_categories( $YOUR_POST_ID ) );