How To Memorize User's Progress Through The Application?

I'm facing an architecture problem I didn't manage to solve. I'm developing a little game in PHP and Javascript, and I need to save the user's progress. Now, the problem is that PH

Solution 1:

You're going to want to do the different last_level calculations on the server. That way the user can't hack around with the JavaScript, and submit something on a specially crafted form. So depending on what your storage system is (KV store, Database, Textfile, etc.), put that value in there, and retrieve it.

Ajax can help you out, but isn't necessary. It depends on how your game is set up. But if they complete the level, the server needs to be notified.

Solution 2:

If a user completes a level and then stays on the same page doing additional work:

Then you'll probably want Ajax to send the new level info to the server as soon as the new level has been achieved. Thus:

1. Use cookies to store your php session id

2. From your Javascript client, use Ajax to invoke a php url on your server whenever the user wins a new level. Send the new level as a parameter. Can use POST or GET, doesn't matter.

3. The php program will receive the session id in the cookie, and the new level as a parameter. The php program will look up the user id from the session id, then store the new level the database.

4. Next time the main url of the php program is invoked, it will be able to look up the user's level.

If the user presses "Next" button to go onward to the next level: Use Javascript, not Ajax, to change the POST parameters of the "Next" button.

You'd use POST, not GET, since seeing a url of foo.com/game?level=5 is a bit too obvious for people to cheat your game. POST will not show the level parameter in the url. More security: add a checksum parameter.

If any of the above is not clear, ask in comments or as a follow-up question.

Solution 3:

If you're happy to take javascript's word for it that the level has been completed then just set a cookie from javascript.

an operation that can't be simulated by the user

Sorry - but if it's javascript which dtermines when they've completed the level then there's nothing to stop the user falsifying the results.