Django admin tips and tricks

Ranvir Singh · 15 mins read ·
django django-admin python

Django Admin tips and tricks
Django is one of the best Python frameworks to get started with web development and get out with your product in no time. With Django, you don’t have to worry about any of the things like security, databases or most importantly admin panel.

Django comes with a built-in admin panel that you can use any time of handling any type of internal work. This saves you a lot of development time and also saves you a lot of money as a company.

1. Setup up Django project
2. Change the default admin address.
3. Change the default name of the admin web page
4. Handling History/ Model Logs in Django admin panel
5. Linking Foreign Key fields for navigating properly in Django admin
6. Counting the number of fields
7. Permissions
8. Custom ordering
9. Custom Searching
You can do everything that you can think of using the admin. Some companies start off just by creating their products using the default admin interface. It provides a very good level of users and permissions handling.

In this post, we are going to discuss some tips and tricks in which you can start using the Django admin in your production effectively.

Let’s set up a simple project in Django and try to look at some of the admin related stuff.

Setup up Django project

While we set up the Django project you will know how easy it is to set up a production-based system using this Python framework.

All you need is a working Python environment. For this sake of the tutorial, we are going to use Python 3+. I personally am using Python 3.7+. You can use virtual environments to use any of the new Python versions and keep using the old ones as well.

Here is an old post on how to install a virtual environment on your Ubuntu machine.

For Mac users, you can refer to any of the posts out there. Here is one of them.

Once you install the virtual environment, you can apply the following command to create the virtual environment.

Setting up the virtual environment

python3 -m venv venv
Once the creation of the virtual environment is done you can activate the virtual environment using the following commands.

source venv/bin/activate
You can verify that this process worked if you start getting the environment name behind the directory name in the shell.

(venv) ➜  ~Documents/soshace
Also you can confirm by checking the Python version.

python -V
You should be able to see the python version.

Python 3.7.4
If you want you can deactivate the virtual environment using the following command.

deactivate

Starting the Django project

For the purpose of this tutorial, we will be creating a simple School management system with as simple as possible execution.

The first step involved is to install Django in the virtual environment. Django default setup comes with the inbuilt SQLite database, so you don’t have to worry about that as well. That is enough for the purpose of the tutorial.

pip install django
Also, it is recommended to add the installed packages in a separate requirements.txt file so that anyone can copy your code and setup without going much in the detail. There is a command to help you with that as well.

pip freeze > requirements.txt
Then people can directly call this command to install all the dependencies.

pip install -r requirements.txt
To start the Django project, use the following command.

django-admin startproject schoolproject
This command will create a simple Django project with everything included. This will involve default admin system, default database migrations and many more things.

Now change the working directory to the project that you just created.

cd schoolproject
You will the manage.py file which will include all the runnable commands for Django. Run the following command to create the default tables in the database. Django sample project also creates the default migrations which will create all the required tables for you.

These migrations include one for the user table which we will use to log in to the admin system. Run the following command to create the tables

python manage.py migrate
For logging in to the admin system you will need to create a superuser.

python manage.py createsuperuser
This will prompt you to tell some simple stuff like username and password.

Once this is done you can start the Django server using the following command.

python manage.py runserver
This will start the server on the default port 8000. The default admin page can be found on the /admin endpoint. Use the link http://127.0.0.1:8080/admin to land on the admin page.

Use the same credentials to log yourself in that you just set up a few seconds ago.

In a Django project, everything is handled using apps. You can create a simple app using the following command.

python manage.py startapp schoolapp
Include this newly created app in the settings file.

INSTALLED_APPS = [
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
    'schoolapp'
]

Change the default admin address.

It is important to change the default admin address so that attackers have a good hard time getting to your admin page.

Change the following part of the code in the schoolproject/urls.py file.

urlpatterns = [
    re_path('yourcompany/admin/', admin.site.urls),
]
Now you can see the admin page on yourcompany/admin/ endpoint.

Django Admin login page

Change the default name of the admin web page

You can change the default heading and other things of the admin page to make it more personal for your brand.

You can do it in any of your apps. Generally, people create a default base app and do all kinds of such stuff in there.

Write this code in schoolapp/admin.py

from django.contrib import admin

admin.site.site_header = 'MY SCHOOL APP'
admin.site.index_title = 'Your Company'
Django admin page with custom title

Handling History/ Model Logs in Django admin panel

Django history is a simple extendible app in Django which you can use to your advantage and create awesome things with it.

For example storing more accurate data about the changes made in the Django admin panel.

For this, we first have to create the sample models in schoolapp/models.py.

from django.db import models

class School(models.Model):
    school_name = models.CharField(max_length=30)
    address = models.CharField(max_length=30)
    principle_name = models.CharField(max_length=30)

    def __str__(self):
        return str(self.school_name)
Now run the command to makemigrations

python manage.py makemigrations
Now run the migrations to the database.

python manage.py migrate
Now register the new model to the admin, so we can see it in the admin.

from django.contrib import admin

from schoolapp.models import School

@admin.register(School)
class SchoolAdmin(admin.ModelAdmin):
    pass
Now, you can see the model in the home-page of the Django admin.

Django admin home page with registered model
You can simply create the entries in the database by using the admin dashboard directly.

Just go to the history page of the model to find what do we save related to the object. By default, we only store whether any changes were made to the object or not. Let’s say, you want to save more data related to the changes. We can do it in this way.

Django admin history or LogEntry Page 
from django.contrib import admin
from django.contrib.admin.options import get_content_type_for_model
from django.contrib.admin.models import LogEntry, ADDITION

from schoolapp.models import School


@admin.register(School)
class SchoolAdmin(admin.ModelAdmin):

    def save_model(self, request, obj, form, change):
        super().save_model(request, obj, form, change)
        if change:
            change_message = '{} - {} - {}'.format(obj.school_name, obj.address, obj.principle_name)
            LogEntry.objects.create(
                user=request.user,
                content_type=get_content_type_for_model(obj),
                object_id=obj.id,
                action_flag=2,
                change_message=change_message,
                object_repr=obj.__str__()[:200]
            )
We are overriding the default implementation of save_model for that given admin model. This will save everything in the change_message, which is visible in the action column.

Django admin change the data
Django admin history of object being saved

Linking Foreign Key fields for navigating properly in Django admin

One of the worst thing of default version of Django admin is that, it doesn’t link with the Foreign Keys very well for the admin panel.

If you are editing some object on the admin and you want to make change to the linked Foreign key field, you will have to go back to that particular model and make the change over there.

There is no easy way to help you out that can directly link between these two related fields.

To figure out the problem, let’s create a new model named class.

class Class(models.Model):
    class_name = models.CharField(max_length=30)
    school = models.ForeignKey(
        School,
        on_delete=models.CASCADE
    )
    class_teacher = models.CharField(max_length=30)
    section = models.CharField(max_length=30)

    def __str__(self):
        return str(self.class_name)
You will have to run the makemigrations and migrate command as specified above to create the tables.

The corresponding admin code will look something like this.

@admin.register(Class)
class ClassAdmin(admin.ModelAdmin):
    pass
Django Admin default foreign key
Always remember to add foreign keys to readonly fields, otherwise, it will load all the fields into the memory and your servers will start going out of memory. Also, you don’t want someone to change the value of such important field randomly.

@admin.register(Class)
class ClassAdmin(admin.ModelAdmin):

    readonly_fields = ('school',)
Django Admin Read-only field
Now that you have changed the field to readonly, you won’t be able to click on the corresponding field. To solve this you will have to make a few changes to the Admin init function.

...
from django.db import models
from django.urls import reverse
from django.utils.safestring import mark_safe
...

def link_function(field_name):
    def return_function(obj):
        obj_attr = getattr(obj, field_name)
        model = type(obj_attr)
        print(field_name, obj_attr, model)
        return mark_safe('<a href="{}">{}</a>'.format(reverse(
            'admin:{}_{}_change'.format(
                model._meta.app_label,
                model.__name__.lower()
            ), args=(obj_attr.id,)), obj_attr))

    return_function.short_description = field_name
    return return_function


@admin.register(Class)
class ClassAdmin(admin.ModelAdmin):
    readonly_fields = ('school',)

    def __init__(self, model, admin_site):
        super().__init__(model, admin_site)
        # get all the fields
        all_fields = model._meta.get_fields()
        for field in all_fields:
            # Check if the field is a Foreign Key
            if not (isinstance(field, models.ForeignKey)):
                continue

            # We have to set a new field whose value is a function.
            # The function should return inners of a HTML anchor tag.
            setattr(self, 'main_new', link_function(field.name))
            self.readonly_fields += ('main_new',)
I have written a few comments to explain what is going on in there. If you still find something odd, Please let me know in the comments section below.

Django Admin Foreign key linking
Coming up

Counting the number of fields

Permissions

Custom ordering

Custom Searching

About Author

Ranvir Singh

Greetings! Ranvir is an Engineering professional with 3+ years of experience in Software development.

Original Source: Original Post

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