This web application designed for mobile devices is written in javascript/backbone with node.js/postgres on the server side. On the client side, I have a function that takes the data from a contact and parses it into a .vcf ready string. From what I understand, client side javascript doesn't grant access to the file system, and I will probably have to do the actual saving in node. I haven't started on that part yet because I'm concerned that the phones won't allow me to do what I want to do.
I would like to have a button that prompts the user if they'd like to add the contact to their device's contacts. Is this even possible from a web app? I'd appreciate it if someone could point me in the right direction.