Can I use a custom action EXE to set some parameters or registry keys that the setup can read and conditionally perform some file actions based on them?
For example, my custom exe will ask the user if he intends to use a database, in which case the installer needs to copy blank databases to a folder.
In some cases I need the installer to leave installed files intact on the target machine, in other cases I need it to delete them. How do you handle this?
Can I use a custom action EXE to set some parameters or registry keys that the setup can read and conditionally perform some file actions based on them?
Yes and no.
Yes, a custom action can set flags. No, the flags would only be read once by the MSI installation process. Yes, the flags could also be read by other custom actions and take the desired action.
Express is not the best platform for this due to several ingrained limitations and you may want to consider the Premier or Professional editions...
(of Express) no customization of dialogs (their functionality and appearance)
(of MSI) System Search checks conditions once, at the very beginning
(of Express) a more limited Custom Action configuration than with Premier or Professional
In some cases I need the installer to leave installed files intact on the target machine, in other cases I need it to delete them. How do you handle this?
The MSI uninstallation process will leave behind any modified files (ie, configuration files modified post installation) found in the installation directories and any new or otherwise unknown files (say if your custom action copied files on to the target machine).
