Forgive me if I am missing something --- I use custom managers extensively and do not see what your code can do that the django custom managers can't ? Can you provide an example please ?
On Tue, Jan 3, 2012 at 12:55 AM, Zachary Voase <[email protected]>wrote: > At the moment it's very easy to add methods to individual models, just > by putting a method on the model class itself which accepts 'self'. > However, defining business logic on collections of records is > currently pretty complicated — you have to create at least a custom > Manager subclass, and if you want to chain those methods together > you'll need a QuerySet subclass. An example of the desired behaviour, > and the steps required for it, is shown in [1]. > > I originally created django-qmixin [2] to tackle this problem; you can > define methods which will be present on the manager and all querysets > produced therefrom, including on relations. However, the django-qmixin > approach of creating a mixin and then including that on the Manager > class object doesn't really gel with the rest of Django core. I've > worked out two approaches which are easier for novices to understand, > and match the idioms of the rest of Django. They both involve adding a > @models.querymethod decorator, which would be applied to methods which > operate on collections of records (i.e. querysets). It's an analog to > Python's @classmethod. > > The first approach [3] involves adding these querymethods to the model > class itself; the second [4] adds them to a manager subclass (but > without the trouble of the QuerySet subclass). I prefer the former, > for simplicity, but you may believe otherwise. > > I'm working on a proof-of-concept implementation, but I feel it's more > important to agree on the interface and rationale beforehand. Any > thoughts? > > [1]: https://gist.github.com/1553675#file_old_queryset_method.py > [2]: https://github.com/zacharyvoase/django-qmixin > [3]: https://gist.github.com/1553675#file_model_querymethod.py > [4]: https://gist.github.com/1553675#file_manager_querymethod.py > > -- > You received this message because you are subscribed to the Google Groups > "Django developers" group. > To post to this group, send email to [email protected]. > To unsubscribe from this group, send email to > [email protected]. > For more options, visit this group at > http://groups.google.com/group/django-developers?hl=en. > > -- Daniel Sokolowski Web Engineer KL Insight http://klinsight.com/ Tel: 613-344-2116 | Fax: 613.634.7029 993 Princess Street, Suite 212 Kingston, ON K7L 1H3, Canada Notice of Confidentiality: The information transmitted is intended only for the person or entity to which it is addressed and may contain confidential and/or privileged material. Any review re-transmission dissemination or other use of or taking of any action in reliance upon this information by persons or entities other than the intended recipient is prohibited. If you received this in error please contact the sender immediately by return electronic transmission and then immediately delete this transmission including all attachments without copying distributing or disclosing same. -- You received this message because you are subscribed to the Google Groups "Django developers" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/django-developers?hl=en.
