IOS swift rxswift ReactiveX UICollectionView Observable Relay Complatable DisposeBag Disposable didSelectItemAt migration failed dataversioning imagePickerController MobileCoreServices UIImagePickerControllerDelegate forUndefinedKey BehaviorRelay PublishRelay BehaviorSubject RxCocoa Swift5 publishsubject 코린이 Segue 개발블로그 gitignore core data 열심히 공부중 커스텀셀 메모앱 versioning 테이블뷰 UIImagePickerController UINavigationControllerDelegate tableView traits SetValue Dispose 열심히 custom 안드로이드 operator 생명주기 subject driver Touch cell cpp sequence 연산자 Observer executable data 대학생 Single 공부중 시퀀스 에러 Present Maybe event Drive error 리눅스 카메라 시작