I have a formset in my application where there is a select field and also a multiselect field in a form. In some object edit view, number of times each form in the formset gets called increases with the increase of number of relationships between objects in the db(see my question on stackoverflow - http://stackoverflow.com/questions/6591890/django-formsets-slow-on-many-to-many-relationships). Because of the way formsets work this means the number of queries to the db also increase and it causes an unacceptable latency in the view. Although caching is required in the case of multiple requests for the same view, I think the first improvement that should be made is to have the repeated form as a property of formset object(in the first time it gets instantiated) and then use that property as required. Do you see any problems with this?
On May 23, 8:29 pm, Sean Brant <brant.s...@gmail.com> wrote: > If you have ever used a inline in the admin for a model that contained > a model choice field you have probably noticed it has to query the > database for each row to fill the select drop-down. This results in n+ > identical queries. > > I though it might be useful to have a way to tell a admin inline to > cache the choices of fields. Here is some rough code that gets the job > done:: > > from django.forms.models import BaseInlineFormSet > > class CachedInlineFormSet(BaseInlineFormSet): > cached_fields = [] > > def _construct_form(self, i, **kwargs): > form = super(CachedInlineFormSet, self)._construct_form(i, > **kwargs) > for cache_field in self.cached_fields: > field = form.fields[cache_field] > field.cache_choices = True > choices = getattr(self, '_cached_%s_choices' % > cache_field, None) > if choices is None: > choices = list(field.choices) > setattr(self, '_cached_%s_choices' % cache_field, > choices) > field.choice_cache = choices > return form > > class CachedTabularInline(admin.TabularInline): > cached_fields = [] > > def get_formset(self, request, obj=None, **kwargs): > formset = super(CachedTabularInline, > self).get_formset(request, obj=None, **kwargs) > formset.cached_fields = self.cached_fields > return formset > > class MyInline(CachedTabularInline): > model = MyModel > cache_fields = ['myfk'] > > Im not super big on how this patches the classes in various places so > i'm open to better suggestions. Is this something that the admin could > benefit from or is this better kept as a 3rd party tool? -- You received this message because you are subscribed to the Google Groups "Django developers" group. To post to this group, send email to django-developers@googlegroups.com. To unsubscribe from this group, send email to django-developers+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/django-developers?hl=en.
