Add Cage autoname feature & uniqueness requirement

[claireward]

It is possible to create multiple cages with the same ID, which may lead to the mixing up of subjects and improper housing assignments. I am attaching three screen shots to illustrate this issue:

1. Each time a new housing is created, this adds a new record with an ID that is hidden from the housing table. In a screen shot with all housing records shown, you can see there are multiple records for a cage identified with a barcode numbered 32686. There is no error that prevents you from adding a duplicate cage ID.
   

2. It is possible to have more than one cage active simultaneously with the same Cage ID. As shown in this screen shot with only the current cages filtered.
   

3. When adding a cage in the subject view, all of the duplicated cage records appear as an option. In this case the unique identifier corresponding to the cage record is visible (see screen shot below)
   

[rossant]

I think this is by design, a cage represents a unique physical cage with a number written on it, whereas a housing represents which mice are in a given physical cage at a given time, and this information can change over time for the same cage, resulting in multiple housing objects with the same cage number.

[claireward]

Thanks @rossant. This makes sense why there would be duplicate housing records for any given cage. My concern is that the screen shot of the current cage listings (second screen shot), allows for identical cage names. Here there are two cages 32686, which house different subjects. So perhaps there is not necessarily something to prevent two HousingSubject objects existing simultaneously with the same name?