Inno Setup: Install other installer and run it before continuing my install

Question

This is the [Files] portion of my code so far:

[Files]
Source: "other_installer.exe"; DestDir: "{app}"
Source: "myprogram.exe"; DestDir: "{app}"
Source: "data.dat"; DestDir: "{app}"
Source: "otherdata.dat"; DestDir: "{app}"

My program is dependent on another program to run. I've included the installer for this program ("other_installer.exe") in my installer. What I would like to do is launch this installer as soon as it has been copied, before continuing with "myprogram.exe" and the rest.

I've googled and found the documentation for BeforeInstall in the Inno Setup Help, but they don't have an example of running another application. I believe it should be something like this:

[Files]
Source: "other_installer.exe"; DestDir: "{app}"
Source: "myprogram.exe"; DestDir: "{app}"; BeforeInstall: // RUN OTHER_INSTALLER.EXE //
Source: "data.dat"; DestDir: "{app}"
Source: "otherdata.dat"; DestDir: "{app}"

Answer 1

Better for the way you go might be the AfterInstall parameter. The following script will execute the RunOtherInstaller function right after the OtherInstaller.exe file entry is processed. There it tries to execute the just installed OtherInstaller.exe file and if that fails, it reports an error message to the user. Please note that you cannot interrupt the installation from that function, so it's not much safe to do what you want this way:

[Setup]
AppName=My Program
AppVersion=1.5
DefaultDirName={pf}\My Program

[Files]
Source: "OtherInstaller.exe"; DestDir: "{app}"; AfterInstall: RunOtherInstaller
Source: "OtherFile.dll"; DestDir: "{app}"

[Code]
procedure RunOtherInstaller;
var
  ResultCode: Integer;
begin
  if not Exec(ExpandConstant('{app}\OtherInstaller.exe'), '', '', SW_SHOWNORMAL,
    ewWaitUntilTerminated, ResultCode)
  then
    MsgBox('Other installer failed to run!' + #13#10 +
      SysErrorMessage(ResultCode), mbError, MB_OK);
end;