SetMsiProperty.js

// MSI_SetProperty.js <msi-file> <property> <value>
// Performs a post-build fixup of an msi to set the specified property (and add it if it doesn't already exist)

// Constant values from Windows Installer SDK
var msiOpenDatabaseModeTransact = 1;
var msiViewModifyInsert = 1;
var msiViewModifyUpdate = 2;

if (WScript.Arguments.Length != 3) {
    WScript.StdErr.WriteLine("Usage: " + WScript.ScriptName + "file property value");
    WScript.Quit(1);
}

var filespec = WScript.Arguments(0);
var property = WScript.Arguments(1);
//var value = parseInt(WScript.Arguments(2));
var value = WScript.Arguments(2);
var installer = WScript.CreateObject("WindowsInstaller.Installer");
var database = installer.OpenDatabase(filespec, msiOpenDatabaseModeTransact);

WScript.StdOut.WriteLine("Looking for property:" + property);

try {
    var sql = "SELECT Property, Value FROM Property WHERE Property = '" + property + "'";
    var view = database.OpenView(sql);
    view.Execute();
    var record = view.Fetch();

    if (record) {
        while (record) {
            WScript.StdOut.Write("Found: " + record.StringData(0) + ", " + record.StringData(1) + ", " + record.StringData(2));
            if (record.IntegerData(2) != value) {
                WScript.StdOut.WriteLine(" - changing to " + value);
                record.IntegerData(2) = value;
                view.Modify(msiViewModifyUpdate, record);
            }
            else
                WScript.StdOut.WriteLine(" - OK");

            record = view.Fetch();
        }
    }
    else {
        WScript.StdOut.WriteLine("Not found, so adding");
        // There may be a better way to do this?
        sql = "INSERT INTO Property (Property,Value) VALUES ('" + property + "','" + value + "')";
        view = database.OpenView(sql);
        view.Execute();
    }
    view.Close();
    database.Commit();
}
catch (e) {
    WScript.StdErr.WriteLine(e);
    WScript.Quit(1);
}