i want to be able to store and retrieve data online using a username and a password so a userscript that runs on a webpage can have personalized information.For example i want to write notes for users in a forum and want to retrieve them from any computer that my userscript is installed.
I thought google spreadsheets would do the trick but i havent been able to implement it. I also have thought of using something like persistencejs https://github.com/zefhemel/persistencejs/blob/master/docs/sync.md or http://www.sencha.com/products/io/ but neither of them are simple enough for the knowledge on programming i have.
So is there a simple way of doing this?
there is no easy way to do this, you have to store data in your server and create a connection between your server and userscript.
here is how you can do that,
create a login box in your userscript, so users can login.
get username and password and send it your server page with GM_xmlhttpRequest. chrome and firefox support cross domain xhr with GM_xmlhttpRequest, so you will not have problem about that if you are writing that script for firefox or google chrome.
in your server page get username and password and check them for matching in your database, than create json response that contains data for matched user.
get response of request in your userscript and do what you want.