How to retain data on custom page when back/next button clicked when the data is taken from a file? - nsis

Question

I have written a custom component page which is having a rich text box and that text box shows the information which is read from the "component.rtf" file. When I go first time on my custom page it shows me rich text box filled with data, but when I click next or back button and come back to custom page again at that time it shows me the rich text box as blank. It shows nothing.
I have written following code for my custom page-
;-------Custom page variables---------
Var Dialog
Var CustomHeaderText
Var CustomSubText
Var path
Var temp1
Var CONTROL
;-------------------------------------
Page custom nsDialogsPage
;------Custom page function----------
Function nsDialogsPage
StrCpy $CustomHeaderText "Components of My Installer"
StrCpy $CustomSubText "Detail list of components are"
!insertmacro MUI_HEADER_TEXT $CustomHeaderText $CustomSubText
!define SF_RTF 2
!define EM_STREAMIN 1097
nsDialogs::Create /NOUNLOAD 1018
Pop $Dialog
${If} $Dialog == error
Abort
${EndIf}
nsDialogs::CreateControl /NOUNLOAD "RichEdit20A" ${ES_READONLY}|${WS_VISIBLE}|${WS_CHILD}|${WS_TABSTOP}|${WS_VSCROLL}|${ES_MULTILINE}|${ES_WANTRETURN} ${WS_EX_STATICEDGE} 0 10u 100% 110u ''
Pop $CONTROL
FileOpen $4 "$path\components.rtf" r
StrCpy $0 $CONTROL
SendMessage $CONTROL ${EM_EXLIMITTEXT} 0 0x7fffffff
; set EM_AUTOURLDETECT to detect URL automatically
SendMessage $CONTROL 1115 1 0
System::Get /NoUnload "(i, i .R0, i .R1, i .R2) iss"
Pop $2
System::Call /NoUnload "*(i 0, i 0, k r2) i .r3"
System::Call /NoUnload "user32::SendMessage(i r0, i ${EM_STREAMIN}, i ${SF_RTF}, i r3) i.s"
loop:
Pop $0
StrCmp $0 "callback1" 0 done
System::Call /NoUnload "kernel32::ReadFile(i $4, i $R0, i $R1, i $R2, i 0)"
Push 0 # callback's return value
System::Call /NoUnload "$2"
goto loop
done:
System::Free $2
System::Free $3
FileClose $4
nsDialogs::Show
FunctionEnd
;--------Custom page function end------------
In above code it reads the file "components.rtf" and displays it. Can someone tell me how to write the code which will retain this data when I will click Back/Next button on component page.?

Answer 1

It works fine for me. Perhaps you are overwriting $path on another page? Add MessageBox MB_OK $4 after FileOpen to make sure you are able to open the file.
!include MUI2.nsh
Var Dialog
Var CustomHeaderText
Var CustomSubText
Var path
#Var temp1
Var CONTROL
;-------------------------------------
Page custom nsDialogsPage
;------Custom page function----------
Function nsDialogsPage
StrCpy $CustomHeaderText "Components of My Installer"
StrCpy $CustomSubText "Detail list of components are"
!insertmacro MUI_HEADER_TEXT $CustomHeaderText $CustomSubText
!define SF_RTF 2
!define EM_STREAMIN 1097
nsDialogs::Create /NOUNLOAD 1018
Pop $Dialog
${If} $Dialog == error
Abort
${EndIf}
nsDialogs::CreateControl /NOUNLOAD "RichEdit20A" ${ES_READONLY}|${WS_VISIBLE}|${WS_CHILD}|${WS_TABSTOP}|${WS_VSCROLL}|${ES_MULTILINE}|${ES_WANTRETURN} ${WS_EX_STATICEDGE} 0 10u 100% 110u ''
Pop $CONTROL
FileOpen $4 "$path\components.rtf" r
StrCpy $0 $CONTROL
SendMessage $CONTROL ${EM_EXLIMITTEXT} 0 0x7fffffff
; set EM_AUTOURLDETECT to detect URL automatically
SendMessage $CONTROL 1115 1 0
System::Get /NoUnload "(i, i .R0, i .R1, i .R2) iss"
Pop $2
System::Call /NoUnload "*(i 0, i 0, k r2) i .r3"
System::Call /NoUnload "user32::SendMessage(i r0, i ${EM_STREAMIN}, i ${SF_RTF}, i r3) i.s"
loop:
Pop $0
StrCmp $0 "callback1" 0 done
System::Call /NoUnload "kernel32::ReadFile(i $4, i $R0, i $R1, i $R2, i 0)"
Push 0 # callback's return value
System::Call /NoUnload "$2"
goto loop
done:
System::Free $2
System::Free $3
FileClose $4
nsDialogs::Show
FunctionEnd
Function .onInit
; Create a RTF file
InitPluginsDir
StrCpy $path "$PluginsDir" ; Set $path used by the custom page
FileOpen $0 "$path\components.rtf" w
FileWrite $0 '{\rtf1\ansi{\fonttbl\f0\fswiss Helvetica;}\f0\pard{Show {\b Me}}\par{http://example.com/#Funny}\par{Goodbye}}'
FileClose $0
FunctionEnd
!insertmacro MUI_PAGE_COMPONENTS
!insertmacro MUI_PAGE_INSTFILES
!insertmacro MUI_LANGUAGE "English"
Section
SectionEnd