input('course_id'))?->department_id; return [ 'course_id' => ['required', 'integer', Rule::exists('courses', 'id')], 'lecturer_id' => [ 'required', 'integer', Rule::exists('lecturers', 'id')->where('department_id', $departmentId), ], 'academic_term_id' => ['required', 'integer', Rule::exists('academic_terms', 'id')], 'class_name' => ['nullable', 'string', 'max:50'], 'method' => ['nullable', 'string', Rule::in(array_column(ClassMethod::cases(), 'value'))], ]; } }