How to set only 2 models in ContentType?

Question

Django

There is this model:

class Slider(models.Model):
    name = models.CharField(max_length=200, verbose_name='Название')
    image = models.ImageField(upload_to='slider', verbose_name='Изображение')
    content = models.TextField(verbose_name='Текст на слайдере')
    content_type = models.ForeignKey(ContentType)
    object_id = models.PositiveIntegerField()
    content_object = GenericForeignKey('content_type', 'object_id')

    def __str__(self):
        return self.name

    class Meta:
        verbose_name = 'Слайдер'
        verbose_name_plural = 'Слайдеры'

Accordingly, in the field - content_type = models.ForeignKey(ContentType) all models are displayed. And I only need 2.
Accordingly, I have 2 questions.
1) How to do as I described.
2) Is it possible to select already existing elements from the selected Model in the object_id field?

Answer 1

By itself, content_type as a foreign key to any table does not imply any restrictions ... since you are essentially specifying the ID of the type you are referring to (link to the content_type table) and the id of the object itself ....
But you can make a restriction at the form display level where you select one or another model for
the link ... you want to work...
If you don't use the admin panel, but custom forms (or a custom form for the admin panel) - I advise you to simply impose a restriction on the queryset that is issued in the content_type field