protected function set_merge_data( $code ) {

		$attempt = new LLMS_Quiz_Attempt( $this->notification->get( 'post_id' ) );
		if ( ! $attempt->exists() ) {
			return '';
		}
		$lesson = llms_get_post( $attempt->get( 'lesson_id' ) );
		if ( ! $lesson ) {
			return '';
		}

		switch ( $code ) {

			case '{{COURSE_TITLE}}':
				$course = $lesson->get_course();
				if ( $course ) {
					$code = $course->get( 'title' );
				} else {
					$code = '';
				}
				break;

			case '{{GRADE}}':
				$code = llms()->grades()->round( $attempt->get( 'grade' ) ) . '%';
				break;

			case '{{LESSON_TITLE}}':
				$code = $lesson->get( 'title' );
				break;

			case '{{QUIZ_TITLE}}':
				$code = get_the_title( $attempt->get( 'quiz_id' ) );
				break;

			case '{{REVIEW_URL}}':
				$code = $attempt->get_permalink();
				break;

			case '{{STATUS}}':
				$code = $attempt->l10n( 'status' );
				break;

			case '{{STUDENT_NAME}}':
				$code = $this->user->get_name();
				break;

		}// End switch().

		return $code;

	}