Django filters - Using an AllValuesFilter (with a LinkWidget) on a ManyToManyField
- by magnetix
This is my first Stack Overflow question, so please let me know if I do anything wrong.
I wish to create an AllValues filter on a ManyToMany field using the wonderful django-filters application. Basically, I want to create a filter that looks like it does in the Admin, so I also want to use the LinkWidget too.
Unfortunately, I get an error (Invalid field name: 'operator') if I try this the standard way:
# Models
class Organisation(models.Model):
name = models.CharField()
...
class Sign(models.Model):
name = models.CharField()
operator = models.ManyToManyField('Organisation', blank=True)
...
# Filter
class SignFilter(LinkOrderFilterSet):
operator = django_filters.AllValuesFilter(widget=django_filters.widgets.LinkWidget)
class Meta:
model = Sign
fields = ['operator']
I got around this by creating my own filter with the many to many relationship hard coded:
# Models
class Organisation(models.Model):
name = models.CharField()
...
class Sign(models.Model):
name = models.CharField()
operator = models.ManyToManyField('Organisation', blank=True)
...
# Filter
class MyFilter(django_filters.ChoiceFilter):
@property
def field(self):
cd = {}
for row in self.model.objects.all():
orgs = row.operator.select_related().values()
for org in orgs:
cd[org['id']] = org['name']
choices = zip(cd.keys(), cd.values())
list.sort(choices, key=lambda x:(x[1], x[0]))
self.extra['choices'] = choices
return super(AllValuesFilter, self).field
class SignFilter(LinkOrderFilterSet):
operator = MyFilter(widget=django_filters.widgets.LinkWidget)
I am new to Python and Django. Can someone think of a more generic/elegant way of doing this?
