Wix: Change arguments depending on OS

Question

Following the advice of wcoenen, I've decided to try using registration-free COM. This works perfectly, excepting on pre-XP machines, of course. One idea which I thought would be kind of neat would be to add to some files, SelfRegCost='[var]'. It is quite likely that this is not The Right Thing™ but I still want to know how to do it, if only to satisfy my own curiosity. I'm assuming, perhaps incorrectly, that SelfRegCost='[var]' will not cause self-registration if var is an empty string. But this could be wrong.

This is similar to "WIX: How can the registry key be changed based on the OS on which the installer is running ?", but in my case I realize I can (and probably should) use a different component and just don't care.

It is quite likely I'll probably end up using a different component anyhow, but please satisfy my curiousity.

Answer 1

I haven't had to do COM installation with WiX (thank god). But from the docs and this thread, it sounds like SelfRegCost is just there to give MSI an idea how much space it needs to verify is available. I'm guessing blank will either be an error, or be treated as a zero and still install the DLL.

I would definately go with the multiple components.

Answer 2

You need to use conditional components to install in different ways to different OS's.

What you are suggesting is to have part of the installation fail, but hopefully silently.

Using a custom action, you can do just that!

<CustomAction Id="YourId" Directory="INSTALLDIR" ExeCommand='regsvr32.exe /s "[INSTALLDIR]YourCOM.dll"' Return="ignore" />

This is of course not recommended for the slew of reasons Rob Mensching provides.