Setting task value based on active file type associations when upgrading - windows

Question

I have the following tasks as part of my installer:
[Tasks]
Name: register32; Description: "Meeting Schedule Assistant (32 bit)"; \
GroupDescription: "{cm:FileAssociations}"; flags: unchecked exclusive;
Name: register64; Description: "Meeting Schedule Assistant (64 bit)"; \
GroupDescription: "{cm:FileAssociations}"; Check: IsWin64; Flags: exclusive;
By design, Inno Setup has UsePreviousTasks set to Yes. However, my software installs both bit editions and the user may subsequently override the installer default via application settings.
Therefore, when my installer is upgrading, can it determine which bit edition is actively registered and leave it set as that value?

Answer 1

Based on your previous question, I know that your registrations look like:
[HKEY_CLASSES_ROOT\MeetSchedAssist.MWB\Shell\Open\Command]
#="\"C:\\Program Files (x86)\MeetSchedAssist\MeetSchedAssist.exe\" \"%1\""
[HKEY_CLASSES_ROOT\MeetSchedAssist.MWB\Shell\Open\Command]
#="\"C:\\Program Files\MeetSchedAssist\MeetSchedAssist_x64.exe\" \"%1\""
So you can query the registered command and look for a respective executable name in the command.
procedure InitDefaultFileAssociationsTaskValue;
var
SubKeyName, Command: string;
begin
SubKeyName := 'MeetSchedAssist.MWB\Shell\Open\Command';
if not RegQueryStringValue(HKCR, SubKeyName, '', Command) then
begin
Log('MWB registration not found');
end
else
begin
Log(Format('Command registered for MWB is [%s]', [Command]));
Command := Lowercase(Command);
if Pos('meetschedassist_x64.exe', Command) > 0 then
begin
Log('Detected 64-bit registration');
WizardSelectTasks('register64');
end
else
if Pos('meetschedassist.exe', Command) > 0 then
begin
Log('Detected 32-bit registration');
WizardSelectTasks('register32');
end
else
begin
Log('Registration not recognised');
end;
end;
end;
procedure CurPageChanged(CurPageID: Integer);
begin
if CurPageID = wpSelectTasks then
begin
{ Only now is the task list initialized. }
InitDefaultFileAssociationsTaskValue;
end;
end;
You may want to modify this to change the task selection only the first time the user enters the tasks page.
var
SelectTasksVisited: Boolean;
procedure CurPageChanged(CurPageID: Integer);
begin
if CurPageID = wpSelectTasks then
begin
{ Only now is the task list initialized. }
if not SelectTasksVisited then
begin
InitDefaultFileAssociationsTaskValue;
SelectTasksVisited := True;
end;
end;
end;