Custom 404 in Snap Web Framework

Question

I am building a website with Snap. How do I specify a custom 404 handler to capture all routes that don't exist?

I would like to redefine the default:

No handler accepted "/asdfasdf"

Thanks

Answer 1

The correct way to modify the routing behaviour is by using wrapSite :

wrapSite (\site -> site <|> writeBS "Use your custom 404 handler" )

In the example code, you can add this line in your base Initializer. In Snap Init code, it would be in the do from app function.

---

Also "" will match for any route given. Example:

routes = [ ("/login",    with auth handleLoginSubmit)
         , ("/logout",   with auth handleLogout)
         , ("/new_user", with auth handleNewUser)
         , ("/static", serveDirectory "static")
         , ("",        writeBS "This if none of the others" )
         ]

You can change the handler for "" to be your custom 404.