Simple Questions from a n00b

I'm having an issue with two of my interfaces.

 

1. For the interface that manages the employees in an editable grid, I want to have a dropdown box that selects who that person reports to. In the CDT for employees, I have a field called "isSupervisor" that is boolean. I want only the people that have that field set to "true" to show up in the dropdown. I tried using: 

 

choiceValues/Labels: index(local!newEmployee.firstName, where(local!newEmployee.isSupervisor))

 

and various other configurations for a default value. I'm not sure if those are the right functions to use, and whenever I don't get parameter errors, local!newEmployee.isSupervisor seems to be passing a null value, which value parameters don't like. As far as I know, that variable should not be passing a null value, because, without that dropdown box, the interface works and I was able to add data to the data store. I don't understand 100% how index() works and I'm assuming, from the documentation, that where() should parse the array and only return the variables that are true, by default.

 

2. In the interface for adding vehicles to the inventory, all of the variables update when I input data. Except for the username and vehicle field. They are setup thusly:

 

username:

 

 

vehicle:

 

 

These components produce the proper values, but they do not update the declared rule inputs. So, if I use a!writeToDataStoreEntity(), it doesn't work, because those values are still null. I thought about using local variables and wrapping those text boxes in a with(), but I don't know if that would work or not. I haven't tried it.

 

Any help would be appreciated.