#22158: Allow model level custom lookups
-------------------------------------+-------------------------------------
Reporter: Anssi Kääriäinen | Owner: nobody
Type: New feature | Status: new
Component: Database layer | Version: dev
(models, ORM) |
Severity: Normal | Resolution:
Keywords: | Triage Stage: Accepted
Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------
Comment (by Simon Charette):
With the approach we've taken with `RegisterLookupMixin` this could be
implemented by
1. Having `models.Model` extend `RegisterLookupMixin`
2. Adding a `lookup` decorator as described above that wraps the decorated
function in something that has a `contribute_to_class` method. This method
would then call `model.register_lookup` with a lookup factory.
3. Adjusting `sql.Query.build_lookup` to consider `self.model.get_lookup`
and call into the wrapped function with `rhs`
e.g. the object that could be registered as a model lookup would be
something like
{{{#!python
class ModelLookupFactory:
def __init__(self, method):
self.model = None
self.method = method
def contribute_to_class(self, cls, name, private_only=False):
self.model = cls
cls.register_lookup(self, name)
def __call__(self, rhs):
# XXX: Use introspection on self.method to avoid passing rhs
# if the arity of self.method is 1. Ensure isinstance(rhs, bool)
# and negate if necessary
return lookups.Exact(self.method(self.model, rhs), True)
lookup = ModelLookupFactory
}}}
--
Ticket URL: <https://code.djangoproject.com/ticket/22158#comment:5>
Django <https://code.djangoproject.com/>
The Web framework for perfectionists with deadlines.
--
You received this message because you are subscribed to the Google Groups
"Django updates" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
To view this discussion on the web visit
https://groups.google.com/d/msgid/django-updates/01070182c8b9f136-5fe67546-f3f5-443e-886e-e9af62a85528-000000%40eu-central-1.amazonses.com.
