[APBeta] Problems with User-defined Fields

[Paul Rodman]

On Jan 3, 2009, at 10:33 AM, Bruce Pipes wrote:

> The converter put my user defined fields in the User-Defined Fields  
> box in the lower right hand corner of the Objects window, but they  
> do not show up in the Edit List Columns window.
>
> When I create a user-defined field from scratch via control-click on  
> the User-Defined Fields box, it works fine. i.e. my field appears  
> both in the list columns and in the box. However, when I try to  
> delete a user-defined field, it disappears from the list columns,  
> but not from the User-Defined Fields box.
>
> Would it be possible to make it so that one can just create and  
> delete user defined fields by clicking and typing in the box, rather  
> than having to go the control-click route?

OK, here's the skinny on user-defined object fields:

In V1, four user fields were permanently defined for every plan  
document. You couldn't get rid of them. They were always available for  
display, even if they weren't being used for anything.

In V2, things have been generalised. You can now have zero to n user  
fields defined, where n could be a large number (although I wouldn't  
go too nuts, esp since the object list is restricted to a max of 63  
visible columns).

User-defined fields must be defined for a plan document in order for  
them to be visible in columns (right-click the User-defined Fields  
list on the Objects tab). If you remove a field definition (via the  
same right-click), any values that were defined don't disappear from  
the object record. They are shown in a grey colour. If you see such an  
item, it means that there is no user-field definition for it. Creating  
one will automatically "assimilate" any fields with the same Parameter  
name, and (a) they will be shown in black, and (b) you can then show  
that column in the object list.

This added complexity is one reason that the object column editing has  
been somewhat flakey.

The advantage of the new method is that you're not limited to four  
additional columns, and those columns can have a variety of different  
types of data therein.

There's a plan (sic) afoot to be able to define your own columns where  
the contents are determined by a script, which means you'll be able to  
add in your own esoteric formulae/algorithms to allow columns that  
automatically change value (e.g. Exposure column for imaging, where  
the value would be computed from size, magnitude, altitude, etc.)

Paul R.