Automating registry of django models to the admin

Registering models to django-admin(in general) is not much of a task, but is mostly boring. Many times it might feel like doing a chore. In this post, we'll try to see how we can automate this process.

Normally, models are registered inside the admin.py module of the apps. To automatically register all of our models, we can directly add these lines of code to this file.

from django.contrib import admin
from django.apps import apps

models = apps.get_models()

for model in models:
    admin.site.register(model)

This fetches all the models in all apps and register them to the admin interface. This is especially useful when the django project has a lot of models.

Handling Custom Admin Models

The above code may throw an exception if you have already registered a model somewhere manually in your Django Project. The error message will be similar to

django.contrib.admin.sites.AlreadyRegistered: The model MyModel is already registered in app 'myapp'.

This is happening because django doesn't allow registering a model more than once, and we're doing exactly that.

In such a scenario, you may process in either of the below two mentioned alternatives.

• In case you haven't performed some sort of customization  over the model(MyModel in this example), you can safely remove its manual entry.  Our automated registration of models will take care of this.
• In case you're performing some sort of customization, you can catch the exception and let it pass.

from django.contrib import admin
from django.apps import apps

from .models import MyModel

# my custom registration
@admin.site.register(MyModel)
class MyModelAdmin(admin.ModelAdmin):
    list_display = ('fields', )
    search_fields = ('fields', )

models = apps.get_models()
for model in models:
    try:
        admin.site.register(model)
    except admin.sites.AlreadyRegistered:
        pass

Customizing All Admin Models

Although we have registered all the models, it doesn't display any metadata. This is not very informative for the users who may want some information about the model objects.

We can add a custom  class ModelAdmin for such purposes. In this example, we will try to populate all the model fields to the list_display attribute for the admin models.

from django.apps import apps
from django.contrib import admin

class ModelAdmin(admin.modelAdmin):
    def __init__(self, model, admin_site):
        self.list_display = [field.name for field in model._meta.fields]
        super().__init__(model, admin_site)

models = apps.get_models()
for model in models:
    admin.site.register(model, ModelAdmin)

Hopefully, this saves your day from the mundane task of registering model to the admin interface. Maybe you can use that time to do better things.

See you in another HackAdda post, bye. Keep hacking.