Automattic\WooCommerce\Blocks\BlockTypes

ProductFilterTaxonomy::flatten_terms_list │ private │ WC 1.0

Flatten hierarchical term tree into flat array maintaining depth-first order.

Method of the class: ProductFilterTaxonomy{}

No Hooks.

Returns

null. Nothing (null).

Usage

// private - for code of main (parent) class only
$result = $this->flatten_terms_list( $terms, $result, $visited_ids, $depth );

$terms(array) (required)

Hierarchical terms with children structure.

$result(array) (required) (passed by reference — &)

Reference to result array being built.

$visited_ids(array) (passed by reference — &)

Reference to array tracking visited term IDs to prevent circular references.
Default: array()

$depth(int)

Current recursion depth for bounds checking.

ProductFilterTaxonomy::flatten_terms_list() ProductFilterTaxonomy::flatten terms list code ^{WC 10.3.6}

private function flatten_terms_list( $terms, &$result, &$visited_ids = array(), $depth = 0 ) {
	/**
	 * This is the safeguard to prevent the memory limit issue. We choose 10 as it
	 * should cover most of the cases. Typical e-commerce stores have two or three
	 * levels of category. Extreme cases like Amazon has about 7 levels.
	 *
	 * @see https://github.com/woocommerce/woocommerce/pull/60142/files#r2250287050
	 */
	if ( $depth > 10 ) {
		return;
	}

	if ( ! is_array( $terms ) ) {
		return;
	}

	foreach ( $terms as $term ) {
		// Validate term structure.
		if ( ! is_array( $term ) || ! isset( $term['term_id'] ) ) {
			continue;
		}

		$term_id = $term['term_id'];

		// Prevent circular references.
		if ( isset( $visited_ids[ $term_id ] ) ) {
			continue;
		}

		$visited_ids[ $term_id ] = true;
		$result[ $term_id ]      = $term;

		if ( ! empty( $term['children'] ) && is_array( $term['children'] ) ) {
			$this->flatten_terms_list( $term['children'], $result, $visited_ids, $depth + 1 );
			unset( $result[ $term_id ]['children'] );
		}
	}
}