How to find the setup location in an VBScript custom action for InstallShield?

Question

In an InstallShield project I have a VBScript custom action that conditionally needs to execute a certain file packaged with the install.

Normally I get the current directory of a vbs using code such as

sCurPath = CreateObject("Scripting.FileSystemObject").GetAbsolutePathName(".")

Which, if it returned the location of the Setup.exe that initiated the install, should work.

However when running the install, the current path (on XP) is C:\Windows\system32 instead of the location of the Setup.exe file I was expecting.

Assuming the output of my InstallShield build looks like the following

Disk1
->Setup.exe
->ISSetupPrerequisites
-->Req1
-->Req2
-->...
->OtherReqs
-->ConditionallyRunMe.exe

How could I run "\OtherReqs\ConditionallyRunMe.exe" from a VBScript custom action?

Thanks!!

(Note: I realize there are ways to conditionally run exe files from withing InstallShield, but in this case the requirements are not supported by InstallShield - unless there is a way to use a VBScript custom action return value as a condition to run another file?)

Answer 1

After a lot of messing around, I got it (actually found it in the InstallShield manual, and not Google, go figure :))!

This line of VBScript does the trick

disk1Path = Session.Property("SETUPEXEDIR")

The line above points to where ever the setup exe file was, so from there it's trivial to run any exe included with your install media.

Other useful ones I found, which I'll past here for reference are

'points to app data\downloaded install directory
MsgBox Session.Property("SourceDir")
'where the software wants to install to on the users system
MsgBox Session.Property("INSTALLDIR")

Not sure why it's so hard to find a good reference on MSI Standard properties (even just a list). The closest I found was this, but not all of them work (and not specifically for InstallShield at all). If anyone finds a good link with documentation about MIS Standard properties and their description please add a link here, so no one has to waste as much time on this as I did :).