conditional !define

I apologize, but this is a pretty basic question.
I was trying to use !define to have conditional actions in the install/uninstall process until I released jumping over the !define lines wasn't really skipping them. How can I have this functionality in NSIS? I basically want to set a "flag" in the onInit function and know about it or the lack of it in the main section.

Thanks in advance!

Sounds like you may be confusing compile time with run time.

Compile time instructions begin with a "!" symbol and get processed once while your setup is compiling. Compile time conditionals include !if, !ifdef,and !ifmacrodef. The !define command is also a compile-time command

Run-time conditionals are processed at runtime (when the user is actually running the installation).

Based on your explanation, I'd say you are likely looking for a run-time conditional.

LogicLib, can make run-time decisions easy. Let's say you use use the variable $Flag to control. You might use something like this:

${If} $Flag == "1"

   ; do something here for flag value 1

${Else}

   ; do something here for other flag values

${EndIf}

Ah, I guessed !define was compile time but I didn't know ! meant that 🙂

Thanks for your help!