htmlburger / carbon-fields

			if ( empty( $rule['compare'] ) ) {

				$rule['compare'] = '=';

			}

			if ( ! in_array( $rule['compare'], $allowed_operators ) ) {

				Incorrect_Syntax_Exception::raise( 'Invalid conditional logic compare operator: <code>' .

					$rule['compare'] . '</code><br>Allowed operators are: <code>' .

				implode( ', ', $allowed_operators ) . '</code>' );

			}

			if ( $rule['compare'] === 'IN' || $rule['compare'] === 'NOT IN' ) {

				if ( ! is_array( $rule['value'] ) ) {

					Incorrect_Syntax_Exception::raise( 'Invalid conditional logic value format. ' .

			$relation = strtoupper( $array[ $relation_key ] );

		}

		if ( ! in_array( $relation, $allowed_relations ) ) {

			Incorrect_Syntax_Exception::raise( 'Invalid relation type ' . $relation . '. ' .

			'The rule should be one of the following: "' . implode( '", "', $allowed_relations ) . '"' );

		}

		return $relation;

	}