Django - Tutorial 050. Creating Dynamic Site Settings Using SingletonModel

Django, SingletonModel, singleton, Model

Let's say you create a site with CMS based on Django, which must have some kind of dynamic site settings that will be available to the user. For example, the name of the site, some specialized information, while you take into account the possibility of multilingualism. What then can be used for this? I got the idea to use a database.

To implement this, the following is required:

  1. Creating a data model that will always contain only one object, that is, only one record. That is, it will be a Singleton Model.
  2. Prohibit deleting this entry and creating new ones in the Django admin panel
  3. The ability to use information from this model directly in the template, without loading the site settings in the view function.

Let's figure out in order how to implement this.

1. SingletonModel

I found on GitHub the code of the abstract SingletonModel, which was written back in 2012. Here is a link to gist .

Here is the code for this SingletonModel

class SingletonModel(models.Model):
    class Meta:
        abstract = True

    def save(self, *args, **kwargs):
        super(SingletonModel, self).save(*args, **kwargs)

    def load(cls):
            return cls.objects.get()
        except cls.DoesNotExist:
            return cls()

The model in the save method automatically saves all the others when saving the object, which allows you to always keep only one instance of this model in the database.

The load method takes from the database the only settings object, if the object does not exist in the database, it returns a new instance of this model, which will need to be saved later.

Let's create a custom settings class to use it for our needs in the future.

# -*- coding: utf-8 -*-

from django.db import models
from django.utils.translation import ugettext_lazy as _

from my_app.singleton_model import SingletonModel

class SiteSettings(SingletonModel):
    site_url = models.URLField(verbose_name=_('Website url'), max_length=256)
    title = models.CharField(verbose_name=_('Title'), max_length=256)

    def __str__(self):
        return 'Configuration'

2. Setting up the administration panel

Now you need to prohibit deleting this entry and creating new ones in the Django admin panel.

# -*- coding: utf-8 -*-

from django.contrib import admin
from django.db.utils import ProgrammingError

from my_app.models import SiteSettings

class SiteSettingsAdmin(admin.ModelAdmin):
    # Create a default object on the first page of SiteSettingsAdmin with a list of settings
    def __init__(self, model, admin_site):
        super().__init__(model, admin_site)
        # be sure to wrap the loading and saving SiteSettings in a try catch,
        # so that you can create database migrations
        except ProgrammingError:

    # prohibit adding new settings
    def has_add_permission(self, request, obj=None):
        return False

    # as well as deleting existing
    def has_delete_permission(self, request, obj=None):
        return False, SiteSettingsAdmin)

Now the settings can be used in Python code

3. Creating a context processor to load settings into a template

# -*- coding: utf-8 -*-

from evileg_settings.models import SiteSettings

def load_settings(request):
    return {'site_settings': SiteSettings.load()}

Then we connect load_settings

        'BACKEND': 'django.template.backends.django.DjangoTemplates',
        'DIRS': [],
        'APP_DIRS': True,
        'OPTIONS': {
            'context_processors': [
                # Загружаем наши настройки при каждом рендеринге шаблона с контекстом

Usage in the template

<h1>{{ site_settings.title }}</h1>


So quickly and simply, you can implement simple dynamic site settings in Django and then bind them to all the site parameters that interest us.
The advantage of this approach will be the ability to use foreign keys for some special data on the site, as well as the use of django modeltranslation, which means there will be no problems with multilingualism.

We recommend hosting TIMEWEB
We recommend hosting TIMEWEB
Stable hosting, on which the social network EVILEG is located. For projects on Django we recommend VDS hosting.
- company blog
Support the author Donate


Only authorized users can post comments.
Please, Log in or Sign up

Hello, Dear Users of EVILEG!!!

If the site helped you, then support the development of the site financially, please.

You can do it by following ways:

Thank you, Evgenii Legotckoi

Dec. 5, 2019, 8:01 a.m.
Sergej Bederin

C++ - Test 001. The first program and data types

  • Result:60points,
  • Rating points-1
Dec. 4, 2019, 6:39 a.m.
Artur Salmin

C++ - Test 005. Structures and Classes

  • Result:33points,
  • Rating points-10
Dec. 2, 2019, 4:05 p.m.
Sergej Timchenko

Qt - Test 001. Signals and slots

  • Result:68points,
  • Rating points-1
Last comments
Dec. 5, 2019, 4:15 p.m.
Evgenij Legotskoj

В этом слоте ваам нужно будет правильно смаппить координату. У QGraphicsView есть методы mapToScene, mapFromScene. Попробуйте использовать их.
Dec. 5, 2019, 8:30 a.m.
Leonid Pivovarov

А без переопределения qgraphicsScene это сделать возможно? Есть же коорината нажатия кнопки мыши slotCustomMenuRequested(QPoint)
Dec. 5, 2019, 8:11 a.m.

//qDebug()<<"position:"<<event->pos(); //qDebug()<<"position:"<<event->screenPos(); qDebug()<<"position:"<<event->scenePos();
Dec. 5, 2019, 8:09 a.m.
Leonid Pivovarov

Подскажите пожалуйста, К graphicsView я подключил обработку контекстного меню: сonnect(ui->graphicsView, SIGNAL(customContextMenuRequested(QPoint)), this, SLOT(slotCustomMenuRequest…
Dec. 4, 2019, 3:49 p.m.
Evgenij Legotskoj

resources_big - это флаг для сборки c++ приложения. Если Nuitka не предоставляет какой-либо функционал для прикручивания конфигурационных директив типа CONFIG при компиляции, то сомнева…
Now discuss on the forum
Dec. 5, 2019, 4:12 p.m.
Evgenij Legotskoj

Это уже кастомная стилизация. Придётся отключать обрамление и самостоятельно реализовывать ресайз окна, его перемещение, стиль и т.д. Вот статья, как отключить обрамление окна - QML …
Dec. 5, 2019, 4:27 a.m.

Вот код, вдруг, кому поможет. Код основной формы: import QtQuick 2.12import QtQuick.Controls 2.12import QtQuick.Layouts 1.3import "./Components/Panels" as PanelsApplicationWindow{…
Dec. 5, 2019, 2:50 a.m.
Evgenij Legotskoj

Создавайте новые темы, чтобы не было всё в куче.
Dec. 4, 2019, 10:07 p.m.

Спасибо за помощь! :) Я попытаю надежды в ожидании QtQuick3D от Riverbank'a. :)
Dec. 4, 2019, 7:02 a.m.

Со временем распаковки соласен - для слабых ноутов это проблема и именно Nuitka мог бы здесь помочь, если бы заработало. А QtlFW - это уже фреймфорк для создания инсталятора из имеющихся па…
© EVILEG 2015-2019
Recommend hosting TIMEWEB