django-autogfk 0.4.2

AutoGenericForeignKey: Admin-friendly GenericForeignKey with Select2 autocomplete for Django.

django-autogfk

Admin-friendly GenericForeignKey for Django — Select2 autocomplete, smart field creation, and an example project.

django-autogfk makes working with GenericForeignKey in Django a first-class experience.
Instead of clunky dropdowns and raw IDs, it gives you a Select2-based interface with autocomplete, filtering, and pagination, just like autocomplete_fields for normal ForeignKeys.

✨ Features

• Drop-in: AutoGenericForeignKey automatically creates the underlying *_content_type and *_object_id fields.
• Beautiful Select2 widget in the Admin (content type ➜ object) with AJAX search and pagination.
• Supports limit_choices_to, null/blank, related_name just like regular fields.
• AutoGenericAdminMixin integrates seamlessly with Django Admin.
• Example project included (example/) so you can try it out instantly.

Requirements: Django 4.2+ (also tested on 5.0)
License: MIT

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📦 Installation

From PyPI (recommended):

pip install django-autogfk

From source (editable):

git clone https://github.com/sandro-salles/django-autogfk.git
cd django-autogfk
pip install -e .[dev]

Add autogfk to INSTALLED_APPS:

INSTALLED_APPS = [
    # ...
    "django.contrib.admin",
    "django.contrib.contenttypes",
    "autogfk",
]

Include URLs (for the autocomplete endpoint):

# urls.py (project)
from django.urls import include, path

urlpatterns = [
    path("admin/", admin.site.urls),
    path("_autogfk/", include("autogfk.urls")),  # ← required
]

The package uses Select2 shipped with Django Admin — no extra frontend deps.

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🚀 Quickstart

1) Define your model using AutoGenericForeignKey

# models.py
from django.db import models
from autogfk.fields import AutoGenericForeignKey

# Example: allow only content types from specific apps
OWNER_LIMIT_CHOICES_TO = {"app_label__in": ["auth", "bots"]}

class Example(models.Model):
    owner = AutoGenericForeignKey(
        null=True,
        blank=True,
        limit_choices_to=OWNER_LIMIT_CHOICES_TO,
        related_name="examples",
        label="Owner",
    )

    name = models.CharField(max_length=120, blank=True, default="")

This automatically creates the concrete fields:

• owner_content_type = ForeignKey(ContentType, …)
• owner_object_id = PositiveIntegerField(…)

Run migrations:

python manage.py makemigrations
python manage.py migrate

2) Hook into the Admin

# admin.py
from django.contrib import admin
from autogfk.admin import AutoGenericAdminMixin
from .models import Example

@admin.register(IntelligenceCredentials)
class ExampleAdmin(AutoGenericAdminMixin, admin.ModelAdmin):
    show_app_label_on_ct_field = False # constrols if ct select will show/hide the app_label
    list_display = ("id", "owner", "name")

Open the Django Admin and edit an object:
You’ll see two linked Select2 dropdowns:

1. pick a ContentType (already filtered if you set limit_choices_to),
2. search/select the object of that model via AJAX autocomplete.

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2.1) Use the Admin mixin with a plain GenericForeignKey

You don’t have to migrate your models to AutoGenericForeignKey to get the nice admin UX. Just plug AutoGenericAdminMixin into your ModelAdmin and it will render the same Select2 widget for any existing GenericForeignKey (CT → Object, with autocomplete, validation, and paging).

• Works side-by-side with AutoGenericForeignKey.
• Reads limit_choices_to directly from your ForeignKey(ContentType) (dict, Q, callable, or list/tuple).
• Enforces requiredness based on the physical fields (null/blank) and prevents partial input.
• Toggle labels: show or hide app_label in the CT select.

Example (plain GFK model)

# models.py
from django.contrib.contenttypes.fields import GenericForeignKey
from django.contrib.contenttypes.models import ContentType
from django.db import models
from django.db.models import Q

ALLOW_AB = Q(app_label="exampleapp", model__in=["modela", "modelb"])

class ExamplePlainGFK(models.Model):
    target_content_type = models.ForeignKey(
        ContentType,
        on_delete=models.PROTECT,
        limit_choices_to=ALLOW_AB,   # ← the admin mixin will respect this
        null=False, blank=False,     # ← makes the pair required in the form
    )
    target_object_id = models.PositiveIntegerField()
    target = GenericForeignKey("target_content_type", "target_object_id")

    def __str__(self):
        return f"{self.target_content_type} #{self.target_object_id}"

# admin.py
from django.contrib import admin
from autogfk.admin import AutoGenericAdminMixin
from .models import Example

@admin.register(ExamplePlainGFK)
class ExamplePlainGFKAdmin(AutoGenericAdminMixin, admin.ModelAdmin):
    list_display = ("id", "target")
    # optional - controls if the CT select will show/hide the app_label
    show_app_label_on_ct_field = False

    # optional - controls if the widget is enabled for plain GenericForeignKey fields as well
    enable_plain_genericforeignkey = True

🧩 Example project (runnable)

A fully working Django project lives in example/:

cd example
python -m venv .venv && source .venv/bin/activate
pip install -r requirements.txt
python manage.py migrate
python manage.py createsuperuser
python manage.py runserver

Navigate to http://127.0.0.1:8000/admin/ and test the Example model.
It contains:

• ModelA, ModelB and ModelCRequired (sample models),
• Example with three AutoGenericForeignKey fields: field_a, field_b and field_c.

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⚙️ Configuration & Tips

limit_choices_to

You can restrict selectable ContentTypes:

AutoGenericForeignKey(limit_choices_to={"app_label__in": ["exampleapp"]})

For advanced filtering (e.g., per user or per model), subclass the autocomplete view or add permission checks in views.py.

Labels and Related Names

• label="Owner" controls form label/placeholder in the Admin.
• related_name="intelligence_credentials" is propagated to the generated content_type field.

Migrations

Because the field creates the concrete fields in contribute_to_class, the migration system will pick them up after you add the AutoGenericForeignKey. Always run makemigrations after changes.

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🔒 Permissions & Security

The built-in autocomplete view is protected by @staff_member_required.
For multi-tenant or per-object permissions:

• Override the queryset in views.autocomplete to filter objects by request.user.
• Optionally mount a custom URL (e.g., path("autocomplete/", my_view, name="autocomplete")).

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🧰 API Reference (short)

AutoGenericForeignKey(...)

Args (selected):

• ct_field: str | None — name for the ContentType FK (auto: <name>_content_type)
• oid_field: str | None — name for the object ID field (auto: <name>_object_id)
• null: bool / blank: bool
• limit_choices_to: dict | None
• related_name: str | None
• label: str | None — Admin form label

AutoGenericAdminMixin

• Auto-injects a MultiWidget with Select2 + AJAX for every AutoGenericForeignKey on the model.
• Handles initial values and saving back to <name>_content_type / <name>_object_id.

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🧪 Tests

Run the test suite:

pytest

What’s covered (high level):

• Field auto-creation of *_content_type / *_object_id
• Autocomplete view (AJAX response, pagination basics)
• Admin form integration (initials and save path)

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🐛 Troubleshooting

• “The widget isn’t loading as Select2”
  Make sure you’re using Django Admin’s default assets. The package relies on Admin’s bundled Select2.

• “No results appear in the object dropdown”
  Confirm the selected ContentType actually has instances. Try typing to trigger autocomplete.

• “I need different search fields per model”
  Fork/override the autocomplete view and tailor the search_fields heuristic for your models.

• “I want to restrict by user/team”
  Add checks in the autocomplete view using request.user and filter the queryset accordingly.

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🤝 Contributing

PRs welcome!
Ideas:

• Registry to configure per-model search fields.
• Per-model permission hooks.
• Optional support for non-integer identifiers (e.g., UUID) in a future minor version.

Steps:

git clone https://github.com/sandro-salles/django-autogfk.git
cd django-autogfk
python -m venv .venv && source .venv/bin/activate
pip install -e .[dev]
pytest

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📄 License

MIT — permissive and simple. See LICENSE.

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💡 Credits

Built to make GenericForeignKey feel as smooth as a regular ForeignKey in the Django Admin. Enjoy!