I'd like to filter the choices that a user can choose in my ForeignKey Field. I basically have a ForeignKey for the subject of the Test and the actual topic of the Test. These topics come from a different model and are linked to a subject. Now I'd like to filter the choices to only include the topics that are linked to the currently selected subject. Is that possible and if so, how?
models.py
class Test(models.Model):
student = models.ForeignKey(Person, on_delete=models.CASCADE, blank=True, null=True)
subject = models.ForeignKey(Subject, on_delete=models.CASCADE, blank=True, null=True)
thema = models.ForeignKey(Thema, on_delete=models.CASCADE, blank=True, null=True)
school_class = models.ForeignKey(SchoolClass, on_delete=models.CASCADE, blank=True, null=True)
grade = models.FloatField(validators=[MinValueValidator(0), MaxValueValidator(6)], blank=True, null=True)
date = models.DateField(default=datetime.date.today)
def save(self, *args, **kwargs):
if not self.school_class and self.student:
self.school_class = self.student.klasse
return super().save(*args, **kwargs)
class Thema(models.Model):
subject = models.ForeignKey(Subject, on_delete=models.CASCADE, blank=True, null=True)
thema = models.CharField(max_length=50)
CodePudding user response：
If you use django forms you can use the model choice field. In your view you can set your queryset of this choicefield. Zo you can filter it.
fields['your model field'].queryset = yourmodel.objects.filter(your filter parameters)
CodePudding user response：
I think what you are looking for ideally would be ForeignKey.limit_choices_to
Please see the docs:
You can limit the choices available at a model level, which is enforced throughout the django app, including forms automatically.