Django filter many to many field in admin?

django, django-admin, django-models, python

Solution

There is a formfield_for_manytomany. Usage is similar to the answer given by defuz.

ModelAdmin.formfield_for_manytomany(db_field, request, **kwargs)¶

Like the `formfield_for_foreignkey` method, the `formfield_for_manytomany` method can be overridden to change the default formfield for a many to many field. For example, if an owner can own multiple cars and cars can belong to multiple owners – a many to many relationship – you could filter the Car foreign key field to only display the cars owned by the User:

class MyModelAdmin(admin.ModelAdmin):
    def formfield_for_manytomany(self, db_field, request, **kwargs):
        if db_field.name == "cars":
            kwargs["queryset"] = Car.objects.filter(owner=request.user)
        return super(MyModelAdmin, self).formfield_for_manytomany(db_field, request, **kwargs)

Problem

I have three objects: ``` Thing some fields Bucket things = models.ManyToManyField(Thing) User buckets = models.ManyToManyField(Bucket) things = models.ManyToManyField(Thing) ``` When editing my "Bucket" field in the admin, I want to be able to select Things, but only those things that are in the "Things" list on the user currently logged in. How can I do that? In other words, how can I filter the list of Things in the Bucket admin? Thank you very much for your help in advance.

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