Uninstaller related function are not triggered

function Component()
{
	installer.installationFinished.connect(this, register);

	installer.uninstallationStarted.connect(this, unregister);
	//installer.aboutCalculateComponentsToUninstall.connect(this, unregister);
	//installer.finishedCalculateComponentsToUninstall.connect(this, unregister);
}

register = function()
{
	console.log("REGISTER");

	if (installer.isInstaller()) {
		var result = QMessageBox.question("reg.question", "Installer", "REGISTER!", QMessageBox.Yes | QMessageBox.No);
		installer.execute("@TargetDir@/start.bat", ["-i","something.ini"]);
	}
}

unregister = function()
{
	console.log("UNREGISTER");

	if (installer.isUninstaller()) {
		var result = QMessageBox.question("unreg.question", "Uninstaller", "UNREGISTER!", QMessageBox.Yes | QMessageBox.No);
		installer.execute("@TargetDir@/start.bat", ["-u","something.ini"]);
	}
}