Automattic\WooCommerce\Blocks

QueryFilters::attribute_filter_clauses() │ private │ WC 1.0

Add query clauses for attribute filter.

Method of the class: QueryFilters{}

No Hooks.

Return

Array.

Usage

// private - for code of main (parent) class only
$result = $this->attribute_filter_clauses( $args, $wp_query );
$args(array) (required)
Query args.
$wp_query(\WP_Query) (required)
WP_Query object.

QueryFilters::attribute_filter_clauses() code WC 9.4.2

woocommerce/src/Blocks/QueryFilters.php 
private function attribute_filter_clauses( $args, $wp_query ) {
	$chosen_attributes = $this->get_chosen_attributes( $wp_query->query_vars );

	if ( empty( $chosen_attributes ) ) {
		return $args;
	}

	global $wpdb;

	// The extra derived table ("SELECT product_or_parent_id FROM") is needed for performance
	// (causes the filtering subquery to be executed only once).
	$clause_root = " {$wpdb->posts}.ID IN ( SELECT product_or_parent_id FROM (";
	if ( 'yes' === get_option( 'woocommerce_hide_out_of_stock_items' ) ) {
		$in_stock_clause = ' AND in_stock = 1';
	} else {
		$in_stock_clause = '';
	}

	$attribute_ids_for_and_filtering = array();

	foreach ( $chosen_attributes as $taxonomy => $data ) {
		$all_terms                  = get_terms( $taxonomy, array( 'hide_empty' => false ) );
		$term_ids_by_slug           = wp_list_pluck( $all_terms, 'term_id', 'slug' );
		$term_ids_to_filter_by      = array_values( array_intersect_key( $term_ids_by_slug, array_flip( $data['terms'] ) ) );
		$term_ids_to_filter_by      = array_map( 'absint', $term_ids_to_filter_by );
		$term_ids_to_filter_by_list = '(' . join( ',', $term_ids_to_filter_by ) . ')';
		$is_and_query               = 'and' === $data['query_type'];

		$count = count( $term_ids_to_filter_by );

		if ( 0 !== $count ) {
			if ( $is_and_query && $count > 1 ) {
				$attribute_ids_for_and_filtering = array_merge( $attribute_ids_for_and_filtering, $term_ids_to_filter_by );
			} else {
				$clauses[] = "
						{$clause_root}
						SELECT product_or_parent_id
						FROM {$this->get_lookup_table_name()} lt
						WHERE term_id in {$term_ids_to_filter_by_list}
						{$in_stock_clause}
					)";
			}
		}
	}

	if ( ! empty( $attribute_ids_for_and_filtering ) ) {
		$count                      = count( $attribute_ids_for_and_filtering );
		$term_ids_to_filter_by_list = '(' . join( ',', $attribute_ids_for_and_filtering ) . ')';
		$clauses[]                  = "
			{$clause_root}
			SELECT product_or_parent_id
			FROM {$this->get_lookup_table_name()} lt
			WHERE is_variation_attribute=0
			{$in_stock_clause}
			AND term_id in {$term_ids_to_filter_by_list}
			GROUP BY product_id
			HAVING COUNT(product_id)={$count}
			UNION
			SELECT product_or_parent_id
			FROM {$this->get_lookup_table_name()} lt
			WHERE is_variation_attribute=1
			{$in_stock_clause}
			AND term_id in {$term_ids_to_filter_by_list}
		)";
	}

	if ( ! empty( $clauses ) ) {
		// "temp" is needed because the extra derived tables require an alias.
		$args['where'] .= ' AND (' . join( ' temp ) AND ', $clauses ) . ' temp ))';
	} elseif ( ! empty( $chosen_attributes ) ) {
		$args['where'] .= ' AND 1=0';
	}

	return $args;
}