With NSIS can I share values between MUI_PAGE_DIRECTORY pages?

Question

I have two MUI_PAGE_DIRECTORY pages. The first stores the entered data to the default, $INSTDIR. What I would like to do is copy the value in $INSTDIR to the defined var $DataDir so that before the second directory page is displayed, $DataDir becomes $INSTDIR\Data. When the second page is displayed I would like the default value to be $INSTDIR\Data.

Is this possible?

Answer 1

InstallDir $ProgramFiles\MyApp

Var DataDir
!include MUI2.nsh
!define MUI_PAGE_CUSTOMFUNCTION_LEAVE InstDirPageLeave
!insertmacro MUI_PAGE_DIRECTORY
!define MUI_DIRECTORYPAGE_VARIABLE $DataDir
!define MUI_DIRECTORYPAGE_TEXT_TOP "Choose Data directory for bla bla bla..."
!define MUI_DIRECTORYPAGE_TEXT_DESTINATION "Data Directory:"
!define MUI_PAGE_CUSTOMFUNCTION_SHOW DataDirShowPage
!insertmacro MUI_PAGE_DIRECTORY
!insertmacro MUI_PAGE_INSTFILES
!insertmacro MUI_LANGUAGE English

Function InstDirPageLeave
StrCpy $DataDir "$InstDir\Data"
FunctionEnd

Function DataDirShowPage
!insertmacro MUI_HEADER_TEXT "Foo" "Bar"
FunctionEnd

Section
DetailPrint $InstDir
DetailPrint $DataDir
SectionEnd