Using the Null function to delete an attribute from a user in the metaverse

Question

RC1 Update 3 adds a new Null function, which (to me) sounds like it should flow a null value into the destination attribute.  I have a case where i am flowing a date from SQL into the metaverse.  Just for testing, I tried a basic flow of:
Null()->employeeEndDate
This seems to function the same as this:
""-employeeEndDate
Both will add the employeeEndDate attribute to the metaverse object with a blank (not null) value.  To me, Null() seems like it should be equivalent of mventry("employeeEndDate").Delete, but it doesn't seem to.  Ultimately, what I want is to flow the value in if it is present in my connector space, and delete it if it is not.  Something like this:
IIF(IsPresent(TermDate),DateTimeFormat(TermDate,"yyyy-MM-ddTHH:mm:ss.000"),Null())
Anyone have any thouse on this?  Is there an easier to way to do this that I am overlooking?
Thanks,
Keith

Answer 1

So here is a new update on this, with somewhat of a workaround.  I ran into a scenario where I wanted to delete attributes upon removal of a sync rule.  Unless I am missing something, this can't be done normally.  When my sync rule is removed,
the attributes are no longer flowed from the MV to the CS, but they aren't removed from the object in the CS either.
My Scenario:
Only certain users should flow their location info to AD for display in the GAL.
My Solution (these aren’t the real Set/Rule/WF/MPR names, it just makes it easier to understand):
1.      
Create two sets: “Show Info” & “Hide Info”
2.      
Create Sync Rule: “Flow info to AD”
a.      
Dependent on a Sync Rule “AD Base”
3.      
Create Workflow “Apply Flow Info to AD” to apply “Flow Info to AD” Sync Rule
4.      
Create MPR to apply the “Apply Flow info to AD” Workflow on Transition In to “Show Info”
5.      
Create a new Metaverse attribute for people called “nullString”
6.      
Create Sync Rule: “Null Info to AD”
a.      
Dependent on “AD Base”
b.     
Flows the nullString attribute to all AD attributes that need to be blanked out
7.      
Create Workflow “Remove Flow Info to AD” to remove “Flow Info to AD” Sync Rule
8.      
Create Workflow “Apply Null Info to AD” to apply “Null Info to AD” Sync Rule
9.      
Create MPR to apply “Remove Flow Info to AD” and “Apply Null Info to AD” Workflows on Transition In to “Hide Info” set.
Obviously, you’ll need a null MV attribute for each data type you need to blank out, but it works.
I haven't tried it, but it's likely this could also be done on inbound flows, provided you have unused attributes of each type in your data set (with a view you could
just create them).  If X, then flow regular attribute from the CS in to the MV; if not X then flow the "null" attribute from the CS into the MV.
Keith