How to add a WiX custom action that happens only on uninstall (via MSI)?

Question

I would like to modify an MSI installer (created through WiX) to delete an entire directory on uninstall.

I understand the RemoveFile and RemoveFo

Answer 1

Here's a set of properties i made that feel more intuitive to use than the built in stuff. The conditions are based off of the truth table supplied above by ahmd0.

 
 
 "" AND REINSTALL="" AND PREVIOUSVERSIONSINSTALLED<>"" AND REMOVE=""]]>
 ""]]>
 "" ]]>

Here's some sample usage:

  NOT _UNINSTALL
  _INSTALL OR _UPGRADE
  _UNINSTALL OR _UPGRADE
  NOT _UNINSTALL
  NOT _UNINSTALL

Issues:

• UPGRADINGPRODUCTCODE is set during the RemoveExistingProducts action, so any custom actions that you run prior will not know it's an upgrade https://docs.microsoft.com/en-us/windows/desktop/Msi/upgradingproductcode