Can I turn this into a [Run] entry in Inno Setup? [duplicate] - inno-setup

Question

At the end of an installation I need to run a Pascal function that updates a flight simulator .cfg file (called .ini file in Inno Setup). The Pascal function exists in its [Code] section and runs correctly. I would like to run this Pascal function in the [Run] section using StatusMsg to tell the user what is going on.
[Run]
Filename: {code:FsxEditSceneryFile|Add#<scenerySpec>}; StatusMsg: "Add scenery to FSX";
; <scenerySpec> is just a place holder of the actual scenery specification!
All works as expected with the exception that Inno Setup forces me to use a string as return value of the Pascal function. However the Filename statement requires a Boolean as return value to specify if the execution was successful (True) or failed (False). This type mismatch produces an error message box at the end of the execution of the Filename statement saying
CreateProcess failed; Code 87. Wrong Parameter.
Any proposal how this could be solved? I know that event functions exist that I could use e.g. CurStepChanged() but I find the StatusMsg mechanism very nice to tell the user what is done by the installation.

Answer 1

You are abusing Filename parameter resolution to execute some code. It's undocumented when the parameter value is resolved. This makes your approach unreliable. You cannot know that the value is resolved, while the StatusMsg is displaying. And moreover, the value must resolve to an executable path anyway. And Inno Setup will try to execute it (hence the error). What you probably do not want. Do not do that.
Instead, as you already suggested, use the CurStepChanged. You can display the status message from Pascal code by accessing the WizardForm.StatusLabel.
procedure CurStepChanged(CurStep: TSetupStep);
begin
if CurStep = ssPostInstall then
begin
WizardForm.StatusLabel.Caption := 'Installing something...';
{ Install something }
end;
end;

Answer 2

In case somebody else is stumbling across this problem, here's a solution that will allow you to run pascal script procedures "in place" of any statement in the [RUN] section.
I needed to move the execution of a powershell script to the [CODE] section, since the [RUN] section doesn't provide a way of reacting to the exit code of external cmd programs.
As I've got a bunch of sub installers that I need to execute in a particular order within my setup, it's really handy to have the option to control the position of the pascal script within the [RUN] section and not just when entering the [RUN] sections setup step.
It works by using a "dummy" program (like ping) as Filename for the [RUN] statement, then using the build-in BeforeInstall parameter to call the pascal script procedure containing the actual execution logic.
[RUN] section
Filename: "ping"; BeforeInstall: RunSQLSetupScript; Components: "thirds\db"; StatusMsg: "Installing SQL Server ..." ; Flags: runhidden
Pascal script procedure containing the actual execution logic
(Note that {tmp}\{#SQLServerInstallScript} would be the actual path to the script in this example, as it is generally advised to avoid hard coded paths and use constants + the temporary directory instead.)
// runs the SQL setup script and terminates the setup process, if the script returns an exit code that indicates an error
procedure RunSQLSetupScript();
var
runSuccess: Boolean;
retVar: Integer;
msgText: String;
begin
runSuccess := ShellExec('', 'powershell.exe', '-NoProfile -File ' + ExpandConstant('{tmp}\{#SQLServerInstallScript}'), '', SW_SHOW, ewWaitUntilTerminated, retVar);
// the external script will return an exit code > 0 if an error occurred
if (runSuccess = False) or (retVar > 0) then
begin
msgText := 'SQL Server setup script returned error code ' + IntToStr(retVar) + ', indicating an unsuccessful installation of SQL Server. Setup will now terminate.';
MsgBox(msgText, mbCriticalError, MB_OK);
// => further handle error case here, like cancelling the running setup or log the issue etc.
end;
end;