add checking exists and delete
rename parameter and add function generate_filename
Revert "rename parameter and add function generate_filename"

This reverts commit 7d7afd0e843f07262886b959c276415320bcec58.
check file name from backend
add method get_filename
start test
edit test
change import
move get_path(), and modify if statement
Merge pull request #36 from jessicarasidi/storage_exists_delete

add checking exists and delete