djangodjango-modelsdjango-formsdjango-admindjango-contenttypes

How can I restrict Django's GenericForeignKey to a list of models?


Is there a way of telling django that a model having a contenttypes GenericForeignKey can only point to models from a predefined list? For example, I have 4 models: A, B, C, D and a model X that holds a GenericForeignKey. Can I tell X that only A & B are allowed for the GenericForeignKey?


Solution

  • For example, your apps are app and app2 and there are A, B models in app and there are C, D models in app2. you want to see only app.A and app.B and app2.C

    from django.db import models
    
    class TaggedItem(models.Model):
        tag = models.SlugField()
        limit = models.Q(app_label = 'app', model = 'a') | models.Q(app_label = 'app', model = 'b') | models.Q(app_label = 'app2', model = 'c')
        content_type = models.ForeignKey(ContentType, limit_choices_to = limit)
        object_id = models.PositiveIntegerField()
        content_object = generic.GenericForeignKey('content_type', 'object_id')
    

    use limit_choices_to on ForeignKey.

    check django docs for details and Q objects, app_label. you need to write proper app_label and model. This is just code snippet

    plus: I think you write wrong app_label. This can help you.

    from django.contrib.contenttypes.models import ContentType
    for c in ContentType.objects.all():
        print(c.app_label, c.model)