On Fri, Jun 11, 2010 at 4:16 AM, jpeck <peck.j...@gmail.com> wrote:
> I am trying to map to a simple read only property. According to the
> docs, I *think* I am supposed to use synonym. The problem is that I am
> getting a None value for the mapped descriptor's column.
>
Ok, so I got this working with synonym, but I am not sure I am doing
this the best way. As long as I access the descriptor before an insert
or update, the synonym worked ok.
I ended up using a MapperExtension like so:
class UpdatePropertiesExtension(MapperExtension):
def __init__(self, properties):
self.properties = properties
def _update_properties(self, instance):
for p in self.properties:
getattr(instance, p)
def before_insert(self, mapper, connection, instance):
self._update_properties(instance)
def before_update(self, mapper, connection, instance):
self._update_properties(instance)
This works fine for me, but I'm wondering if there is a better way to do this?
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