So some experimentation shows that this API works when the script is run from the VUGen window, but does not work when executed in the browser/development window. That seems crazy, why is the development environment not using the Runtime Settings "Additional attribute" information for the script? Other Runtime Settings values ARE used in the development environment (e.g. Typing interval). This does not make sense...
Seems I am stuck with writing code like this everywhere I want to use a LR attribute in a TruClient script... yikes...
var id_coordinator;
try {
id_coordinator = LR.getLRAttr("id_coordinator");
}
catch (err) {
id_coordinator = "id_for_development_mode";
}