upload class to my project

hello ,

i need to upload a class or create it to use it in my project in a blank application for example .
is there a way to do that ??

If possible I would add it through the libraries. Then it’s - depending on your settings - available for this and other projects too and gets uploaded. If you are talking about standard libraries like jquery (this one is already there, but just for the idea) then you can add it to the lib section. AFAIK all gets uploaded, but it’s simple to try.