[PEAK] Enumeration instances --> values

[Phillip J. Eby]

At 04:58 PM 03/20/2005 -0500, Erik Rose wrote:
>I'm evaluating PEAK's domain modeling machinery for a project at work and 
>have run into a question that's got me stumped. I have this Enumeration:
>
>class HatColor(Enumeration):
>     red = model.enum('REDX')
>     vermillion = model.enum('VERM')
>
>I also have a model that uses it and a mostly-finished toy DM that will 
>pull that model in and out of an RDBMS. My trouble is that I want to store 
>the four-letter codes 'REDX' and 'VERM' in the DB but can't find a way to 
>map from HatColor.red back to 'REDX'. The bulletins example punts and just 
>shoves the string 'HatColor.red' in the DB, which I'd obviously rather not 
>do. Do I have to build my own machinery for this, or will the stock 
>framework somehow let me map Enumeration instances (like HatColor.red) 
>back to values? (I do realize that the main intent of passing values to 
>enum() is to enable compares between values and instances, but mapping 
>from instances to values sure would be nice as well.)

I've just checked in a new 'value' attribute so that you can do this.  E.g. 
'HatColor.red.value' would be 'REDX'.  I'd been planning to do that for a 
while and never got around to it, but it was easier to just add it now than 
to explain why I hadn't gotten around to it yet.  :)