how to read package code through custom action

Question

Is it possible to read package code through custom action as reading ProductCode and ProductName. I want to remove the MSI cache being created in %LOCALAPPDATA%/Downloaded Installations/GUID, where GUID is the package code during uninstallation.

Answer 1

You might want to take a look at this code I wrote awhile back: (the entire thread is a good read)

Local cached MSI does not get deleted when uninstalling

<CustomAction Id="PurgeCache_CAD_Install"  Execute="immediate" Property="PurgeCache" Value="/CacheRoot=[CommonAppDataFolder]Downloaded Installations\MyCompany\MyProduct /PackageCode=[PackageCode] /InstallMode=Install"/>
<CustomAction Id="PurgeCache_CAD_Uninstall" Execute="immediate" Property="PurgeCache" Value="/CacheRoot=[CommonAppDataFolder]Downloaded Installations\MyCompany\MyProduct /PackageCode=[PackageCode] /InstallMode=UnInstall"/>
<InstallExecuteSequence>
  <Custom Action="PurgeCache_CAD_Install" After="ScheduleReboot">Not REMOVE="ALL"/>
  <Custom Action="PurgeCache_CAD_Uninstall" After="ScheduleReboot">REMOVE="ALL"/>
</InstallExecuteSequence>

export prototype PurgeCache(HWND);  

function PurgeCache(hMSI)

    number nResult; 
    string szInstallMode;           
    string szCacheRoot;
        string szDir;
        string szPackageCode;
    LIST listDirs;   

begin

    szInstallMode = MsiGetCustomActionDataAttribute( hMSI, "/InstallMode=" );   
    szCacheRoot = MsiGetCustomActionDataAttribute( hMSI, "/CacheRoot=" );
    szPackageCode = MsiGetCustomActionDataAttribute( hMSI, "/PackageCode=" );

    listDirs = ListCreate (STRINGLIST);
    FindAllDirs( szCacheRoot, EXCLUDE_SUBDIR, listDirs );
    nResult = ListGetFirstString (listDirs, szDir);
    while (nResult != END_OF_LIST);  

        if ( szInstallMode = "Uninstall" || !( szDir % szPackageCode )) then
            DeleteDir( szDir, ALLCONTENTS );
        endif;
        nResult = ListGetNextString (listDirs, szDir);

    endwhile;

 return ERROR_SUCCESS;

end;