I am quite new to web development, so I naturally came to a point where I needed some help. I am making a web site where the user has to log in, and if authentication is successful, the user's data will be fetched from server and displayed on page (and can be edited by user). Because the web site is highly dynamic, the user will click around a lot and change this data, so changes has to be continously uploaded to the server.
I have the index.html where a pop-up box (modal. I'm using Bootstrap) opens for user to enter username and password. That's handed to server with a post command over https (http while developing). a PHP file looks up in the mySQL database and checks if info is corrrect (log in credentials are stored hashed with salt. I'm checking for sql injections also) If it's correct, it echoes "1" back, or "0" if incorrect. The client now knows it’s logged in. But what do I do when the user changes things and new data has to be uploaded to the server? Do I have to pass the username and password to the server again, and to the whole authentican process over again? This may happen more than 30 times a minute.
A have a few other questions as well, but I’ll start with this. I have spent many hours trying to find the answers myself, but I'm really lost in what's the best way of going about this.