Basic Django Admin Panel Setup and registering models

cd ~/tutorials
mkdir customadmin
cd customadmin
python3 -m venv env
source env/bin/activate
pip install --upgrade pip
pip install django django-environ whitenoise
django-admin startproject project .
pip freeze > requirements.txt
./manage.py startapp myapp

# settings.py
INSTALLED_APPS = [
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
    'myapp',
]

mkdir templates

# settings.py
TEMPLATES = [
    {
        "BACKEND": "django.template.backends.django.DjangoTemplates",
        "DIRS": [BASE_DIR / "templates"],
        "APP_DIRS": True,
        "OPTIONS": {
            "context_processors": [
                "django.template.context_processors.debug",
                "django.template.context_processors.request",
                "django.contrib.auth.context_processors.auth",
                "django.contrib.messages.context_processors.messages",
            ],
        },
    },
]

# settings.py
MIDDLEWARE = [
    "django.middleware.security.SecurityMiddleware",
    "whitenoise.middleware.WhiteNoiseMiddleware",
    "django.contrib.sessions.middleware.SessionMiddleware",
    "django.middleware.common.CommonMiddleware",
    "django.middleware.csrf.CsrfViewMiddleware",
    "django.contrib.auth.middleware.AuthenticationMiddleware",
    "django.contrib.messages.middleware.MessageMiddleware",
    "django.middleware.clickjacking.XFrameOptionsMiddleware",
]

# urls.py
from django.contrib import admin
from django.urls import path

urlpatterns = [
    path('admin/', admin.site.urls),
]

from django.contrib import admin
from django.urls import path

urlpatterns = [
    path('myadmin__321/', admin.site.urls),
]

from django.contrib import admin
from django.urls import path
import environ

env = environ.Env()

urlpatterns = [
  path(env('ADMIN_URL', default='admin/'), admin.site.urls),
]

DJANGO_SUPERUSER_PASSWORD=somethingsupersecret123 python manage.py createsuperuser --username=admin --email=admin@example.com --noinput

# models.py
from django.db import models
from django.utils import timezone

from myapp.tuples import ORDER_STATUSES_CHOICES, ORDER_STATUSES


class Category(models.Model):
    name = models.CharField(max_length=200)
    slug = models.SlugField(max_length=200, unique=True)
    is_active = models.BooleanField(default=True, db_index=True)

    class Meta:
        ordering = ('name',)
        verbose_name = 'category'
        verbose_name_plural = 'categories'

    def __str__(self):
        return self.name


class Product(models.Model):
    name = models.CharField(max_length=200)
    slug = models.SlugField(max_length=200, unique=True)
    category = models.ManyToManyField(Category, related_name='products')
    is_active = models.BooleanField(default=True, db_index=True)

    class Meta:
        ordering = ('name',)
        verbose_name = 'product'
        verbose_name_plural = 'products'

    def __str__(self):
        return self.name


class Customer(models.Model):
    first_name = models.CharField(max_length=200)
    last_name = models.CharField(max_length=200)
    phone = models.CharField(max_length=200, unique=True)

    class Meta:
        ordering = ('first_name',)
        verbose_name = 'customer'
        verbose_name_plural = 'customers'

    def __str__(self):
        return ' '.join([self.first_name, self.last_name])


class Order(models.Model):
    customer = models.ForeignKey(Customer, on_delete=models.CASCADE)
    created_dt = models.DateTimeField(auto_now_add=True)
    completed_dt = models.DateTimeField(null=True, blank=True)
    status = models.IntegerField(default=ORDER_STATUSES.new, choices=ORDER_STATUSES_CHOICES)

    class Meta:
        ordering = ('-created_dt',)
        verbose_name = 'order'
        verbose_name_plural = 'orders'

    def __str__(self):
        return str(self.id)

    def save(self, *args, **kwargs):
        if self.completed_dt:
            self.status = ORDER_STATUSES.complete
        if self.status == ORDER_STATUSES.complete and not self.completed_dt:
            self.completed_dt = timezone.now()
        super().save(*args, **kwargs)


class OrderItem(models.Model):
    order = models.ForeignKey(Order, on_delete=models.CASCADE)
    product = models.ForeignKey(Product, on_delete=models.CASCADE)
    quantity = models.PositiveIntegerField(default=1)

    class Meta:
        verbose_name = 'order item'
        verbose_name_plural = 'order items'
        unique_together = ('order', 'product')

    def __str__(self):
        return self.product.name
    ```
Make sure to specify the `__str__` method for each model to display the object's name in the admin interface.

You can also customize the model's metadata by setting the `Meta` class attributes.

For example: 

Meta class attributes `verbose_name` and `verbose_name_plural` are used to set the human-readable name of the model in the admin interface.

The Meta class attribute `ordering` attribute is used to specify the default ordering of objects in the admin interface.

The models `get_absolute_url` method can be used to return the canonical URL of the object.

Create a file `myapp/tuples.py` and put this in it.

Now create new migrations and apply them:

Now let's run the development server and open our admin panel:

The output should be like this:

Open your browser at this URL: (http://127.0.0.1:8000/notadmin123/)[http://127.0.0.1:8000/notadmin123/] because that's where our admin is located.



The credentials are `admin` / `somethingsupersecret123`

You will see this basic admin panel without our models in there.

![image](https://appliku-serverless-static.s3.eu-central-1.amazonaws.com/imgs/f716092aae3f0edd52517f87a09f980a.png)

Let's fix that.




## How to register Django model in the admin site

Let's see some examples how you can register models in Django admin.

### Basic Registration

The simplest way to register a model without creating ModelAdmin classes:

```python
# admin.py
from django.contrib import admin
from .models import Book, Author

admin.site.register(Book)
admin.site.register(Author)

# admin.py
from django.contrib import admin
from .models import Book

class BookAdmin(admin.ModelAdmin):
    list_display = ('title', 'author', 'publication_date')
    list_filter = ('author', 'publication_date')
    search_fields = ('title', 'author__name')
    date_hierarchy = 'publication_date'
    ordering = ('-publication_date',)

admin.site.register(Book, BookAdmin)

# admin.py
from django.contrib import admin
from .models import Book

@admin.register(Book)
class BookAdmin(admin.ModelAdmin):
    list_display = ('title', 'author', 'publication_date')

from django.contrib import admin
from .models import Category, Product, Customer, Order


class CategoryAdmin(admin.ModelAdmin):
    list_display = ('name', 'slug', 'is_active', 'id',)


admin.site.register(Category, CategoryAdmin)


class ProductAdmin(admin.ModelAdmin):
    list_display = ('name', 'slug', 'is_active', 'id',)


admin.site.register(Product, ProductAdmin)


class CustomerAdmin(admin.ModelAdmin):
    list_display = ('first_name', 'last_name', 'phone', 'id',)


admin.site.register(Customer, CustomerAdmin)


class OrderAdmin(admin.ModelAdmin):
    list_display = ('customer', 'created_dt', 'completed_dt', 'status', 'id',)


admin.site.register(Order, OrderAdmin)