Persist List of Objects Between Pages - ASP MVC

Question

C# - ASP MVC - .NET 4.5 - Bootstrap - Razor

I have a form wizard (http://vadimg.com/twitter-bootstrap-wizard-example/examples/basic.html) that is used to setup a complex object (obj1). A property of obj1 is a List<obj2>. On one step of the wizard I want to add multiple obj2's to the list. Since obj2 is slightly complex as well, I thought I would use another wizard to help build it. Except I need to persist this List<obj2> on wizard 1, while I'm off in wizard 2 building another obj2.

My first thought was to use a session to hold the List<obj2>, I was just wondering if that's a good option, or if there would be a better one? The user may leave from Wizard1 to go to Wizard2 and come back multiple times.

Answer 1

There's no perfect answer here; each approach has trade-offs. But here are some options that I can think of (and these are independent of ASP.NET/C#)

• Session (as you suggest)
  • This will store data in web server memory (by default). If you have a lot of users, this could be a problem.
  • You risk the information being lost when the user gets a new cookie/the session times out.
  • Potentially better performance that a db, depending again on the number of users
• Database (as you mentioned)
  • Could cause more database traffic.
  • Can save information for user even if they close a browser, switch computer, the power goes out, etc.
  • Maybe a separate NoSQL database just for transient wizard data would be worth trying.
• Cookie (store data on the user's computer)
  • Users can potentially tamper with/view the data
  • There is a limit on cookie size (4 KB each?)
• Local storage (HTML5)
  • Similar to cookies
  • But not such a small limit
  • Not every browser supports it (may need polyfill)
• Form/Post/Hidden/ViewState
  • You could just post the data and drag the information from response to response
  • But this gets really annoying with back buttons & timeouts
  • Lots of work, and again, the user can tamper with the information