Select section by variable - nsis

Question

!include "MUI2.nsh"
!include "FileFunc.nsh"
!include "LogicLib.nsh"
;---------------------------------------------------------------------------
;---------------------------------------------------------------------------
ShowInstDetails show
RequestExecutionLevel admin
;---------------------------------------------------------------------------
Name "Test"
Outfile "Test.exe"
;---------------------------------------------------------------------------
!insertmacro MUI_PAGE_COMPONENTS
!insertmacro MUI_PAGE_DIRECTORY
!insertmacro MUI_PAGE_INSTFILES
!insertmacro MUI_UNPAGE_CONFIRM
!insertmacro MUI_UNPAGE_INSTFILES
;---------------------------------------------------------------------------
!insertmacro MUI_LANGUAGE "English"
;---------------------------------------------------------------------------
LangString DESC_sec1 ${LANG_ENGLISH} "sec1 files"
Section /o "sec1" sec1
SectionEnd
LangString DESC_sec2 ${LANG_ENGLISH} "sec2 files"
Section /o "sec2" sec2
SectionEnd
LangString DESC_sec3 ${LANG_ENGLISH} "sec3 files"
Section /o "sec3" sec3
SectionEnd
Var test
Function .OnInit
StrCpy $test "sec2"
!insertmacro SelectSection $test
FunctionEnd
How to select section at runtime by section name?
In eample always selected 1st section (think its a bug)
But if i rewrite like this
!insertmacro SelectSection ${sec2}
All works fine...
Is there way to select section by name from variable?
some long text some long text some long text some long text
some long text some long text some long text some long text

Answer 1

Sections are accessed by their ID which is a number set at compile time:
Section "Foo"
SectionEnd
Section "Bar" SID_BAR
SectionEnd
Section "Baz"
SectionEnd
Page Components
Page InstFiles
!include Sections.nsh
Function .onInit
!insertmacro UnselectSection ${SID_BAR}
FunctionEnd
If you want to use the display name then you have to manually enumerate the sections:
Section "Foo"
SectionEnd
Section "Bar"
SectionEnd
Section "Baz"
SectionEnd
Page Components
Page InstFiles
!macro GetSectionIdFromName name outvar
Push "${name}"
Call GetSectionIdFromName
Pop ${outvar} ; ID of section, "" if not found
!macroend
Function GetSectionIdFromName
Exch $1 ; Name
Push $2
Push $3
StrCpy $2 -1
ClearErrors
loop:
IntOp $2 $2 + 1
SectionGetText $2 $3
IfErrors fail
StrCmp $3 $1 "" loop
StrCpy $1 $2
Goto done
fail:
StrCpy $1 ""
done:
Pop $3
Pop $2
Exch $1
FunctionEnd
!include Sections.nsh
!include LogicLib.nsh
Function .onInit
StrCpy $1 "Bar" ; The name we are looking for
!insertmacro GetSectionIdFromName $1 $0
${If} $0 != ""
!insertmacro UnselectSection $0
${EndIf}
FunctionEnd