Exclude parent category post using filters

Fixes #10

includes/class-top-ten-core-query.php

@@ -249,17 +249,45 @@ public function prepare_query_args( $args = array() ) {
 		}
 
 		if ( ! empty( $args['include_cat_ids'] ) ) {
+
+			/**
+			 * Filter to include the parent terms when including terms.
+			 *
+			 * @since 3.4.0
+			 *
+			 * @param bool|string   $include_terms_include_parents    False to exclude only the categories specified,
+			 *                                                        'parent' to include the parent categories and
+			 *                                                        'all' to include all the ancestors. Default is false.
+			 */
+			$include_terms_include_parents = apply_filters( 'top_ten_query_include_terms_include_parents', false );
+
+			$include_terms_include_parents = $include_terms_include_parents ? wz_get_all_parent_ids( wp_parse_id_list( $args['include_cat_ids'] ), $include_terms_include_parents ) : wp_parse_id_list( $args['include_cat_ids'] );
+
 			$tax_query[] = array(
 				'field'            => 'term_taxonomy_id',
-				'terms'            => wp_parse_id_list( $args['include_cat_ids'] ),
+				'terms'            => $include_terms_include_parents,
 				'include_children' => false,
 			);
 		}
 
 		if ( ! empty( $args['exclude_categories'] ) ) {
+
+			/**
+			 * Filter to include the parent categories when excluding categories.
+			 *
+			 * @since 3.4.0
+			 *
+			 * @param bool|string   $exclude_terms_include_parents    False to exclude only the categories specified,
+			 *                                                        'parent' to include the parent categories and
+			 *                                                        'all' to include all the ancestors. Default is false.
+			 */
+			$exclude_terms_include_parents = apply_filters( 'top_ten_query_exclude_terms_include_parents', false );
+
+			$exclude_categories = $exclude_terms_include_parents ? wz_get_all_parent_ids( wp_parse_id_list( $args['exclude_categories'] ), $exclude_terms_include_parents ) : wp_parse_id_list( $args['exclude_categories'] );
+
 			$tax_query[] = array(
 				'field'            => 'term_taxonomy_id',
-				'terms'            => wp_parse_id_list( $args['exclude_categories'] ),
+				'terms'            => $exclude_categories,
 				'operator'         => 'NOT IN',
 				'include_children' => false,
 			);

includes/wz-pluggables.php

@@ -74,3 +74,68 @@ function wz_switch_site_rewrite() {
 	}
 
 endif;
+
+if ( ! function_exists( 'wz_get_all_parent_ids' ) ) :
+
+	/**
+	 * Get all parent term_taxonomy_ids for a given array of term_taxonomy_ids.
+	 *
+	 * @param  int|int[] $term_taxonomy_ids   Array of term_taxonomy_ids or a single term_taxonomy_id.
+	 * @param  string    $levels              Use 'all' for ancestors, 'parent' for the immediate parent.
+	 * @return int[] Array of all parent term_taxonomy_ids merged with $term_taxonomy_ids.
+	 */
+	function wz_get_all_parent_ids( $term_taxonomy_ids, $levels = 'parent' ) {
+		$all_ids = array();
+		$cache   = array();
+
+		foreach ( (array) $term_taxonomy_ids as $term_taxonomy_id ) {
+			if ( isset( $cache[ $term_taxonomy_id ] ) ) {
+				$term = $cache[ $term_taxonomy_id ];
+			} else {
+				$term                       = WP_Term::get_instance( $term_taxonomy_id );
+				$cache[ $term_taxonomy_id ] = $term;
+			}
+
+			if ( $term && ! is_wp_error( $term ) ) {
+				$taxonomy = $term->taxonomy;
+
+				if ( 'all' === $levels ) {
+					$ancestors = get_ancestors( $term->term_id, $taxonomy, 'taxonomy' );
+
+					foreach ( $ancestors as $ancestor_term_id ) {
+						if ( isset( $cache[ $ancestor_term_id ] ) ) {
+							$ancestor_term = $cache[ $ancestor_term_id ];
+						} else {
+							$ancestor_term              = WP_Term::get_instance( $ancestor_term_id );
+							$cache[ $ancestor_term_id ] = $ancestor_term;
+						}
+
+						if ( $ancestor_term && ! is_wp_error( $ancestor_term ) ) {
+							$all_ids[] = $ancestor_term->term_taxonomy_id;
+						}
+					}
+				} else {
+					$parent_id = $term->parent;
+					if ( $parent_id > 0 ) {
+						if ( isset( $cache[ $parent_id ] ) ) {
+							$parent_term = $cache[ $parent_id ];
+						} else {
+							$parent_term         = WP_Term::get_instance( $parent_id );
+							$cache[ $parent_id ] = $parent_term;
+						}
+
+						if ( $parent_term && ! is_wp_error( $parent_term ) ) {
+							$all_ids[] = $parent_term->term_taxonomy_id;
+						}
+					}
+				}
+			}
+		}
+
+		// Perform array operations outside the loop for better performance.
+		$result_ids = array_merge( $term_taxonomy_ids, $all_ids );
+
+		return array_unique( $result_ids );
+	}
+
+endif;