Dfyjkt

If I set

@ENABLESESSIONSTATE = false

then

session("foo") = "bar"

then the result is

Microsoft VBScript runtime error '800a0114'

Variable is undefined 'Session'

... file and line no

It would usually indicate a mistaken assumption regarding program flow and I would trace and fix the issue.

However, in a specific set of circumstances I have a case where a piece of code that uses session is always invoked first on every page request. It is to do with performance monitoring.

This code includes a fork - if the user has a session we go one way, if not we go another.

But of course where the users session is absent because we introduced some code that runs with session disabled, we get the crash.

I could solve it with

on error resume next 
session("foo") = "bar"
if err.number <> 0 then

 ' do the no-has-session fork

else

 ' do the has-session fork
end if
on error goto 0

But I wondered if there is a less hacky approach.

You should be able to determine if the Session object is present using the VBScript function IsObject().

If IsObject(Session) Then Session("foo") = "bar"

This could also become cumbersome to maintain, but you could take it a step further and build a wrapper for setting the Session keys;

Sub SetSessionValue(key, value)
 If IsObject(Session) Then Session(key) = value
End Sub

Usage:

Call SetSessionValue("foo", "bar")

This is just a basic example but should give you are starting point to work from.