Question

When is the proper time to use userdata? Why is it good/not good? And how should I use it properly?

When is it bad/not conventional to use?

Specifically, what’s the best convention/method to utilize the session class:
https://www.codeigniter.com/user_guide/libraries/sessions.html

Answer 1

Sessions should be used whenever you want to preserve state between two different HTTP requests. You generally want to:

• Store session information on the server side (i.e. don’t pass it all back and forth in cookies).
• Protect yourself against Cross Site Forgery Requests (CSFR) by generating a unique key for each request and validating the key when the request returns.
• Store only that information that will need to be accessed repeatedly. (Don’t shove the 5,000+ results of the query you just ran for them into their session for example — use caching instead.)
• Read about PHP’s $_SESSION since CodeIgniter’s session is a wrapper around $_SESSION.
• Understand how to maintain a secure session — and know what CodeIgniter handles for you, and what you will need to do yourself.