For now im using NWjs for create a folder and save the array in a file localy. Its possible to send the file to a server so i can retreive it after?or i have to send it using ajax post to php?
AFAIK, Construct doesn't support ftp,so you can't send an actual file. But as I said before (and dop, trough the other post'slink), you can send via Ajax the file contents (so yes, Ajax post a php(or whatever you like) and then either save a file or to a database). You can always send the byte code of the file as a string too, but I don't see any reason to.
Also, you can connect to a web socket and send a message containing the file content string but, again, there's no need to.
The right way to accomplish what you want is trough Ajax.