Current User Login, Domain and Display Names available in expression

This is useful in the following use cases:

1. You use row-level security at data-source level. This is a top requirement from business in case of of internal reporting!
2. You want to load personalized information (business units, managers and subordinates, favorites, recent changes, areas of interest). This is second request that usually comes from business.
3. Small things like greetings (things that makes your solution better) 

Row-level security:

Whenever we create templates with row-level security in back-end,

we need to send current user login with domain so that data will be filtered.

We use parameters to provide this information natively.

There is no way to get current user information either from document properties or using expressions or any built-in function.

Personalized information:

We create "Setup" page, where user sets common filters. We can make pre-selections made by user: business unit, subordinates, cost centers.

Some templates use it other way: we have list of favorites, recommendations & other areas of interests which rely on current user.

Small things:

It would be great if we could use it in text areas just to greet the user.

Implementation and workarounds:

It is easy to implement on TIBCO side.

From our side we have to write C# extension.

But there are some hidden obstacles: 

1. We should properly handle that property change, because there should be no way to change it from JS API, which in turn makes it a little bit more complicated than anticipated.
2. It is not efficient, as extension updates this property AFTER data source load, while natively it can be done BEFORE.