Django's philosophy of "Don't Repeat Yourself" (DRY) encourages developers to write modular and reusable code. One effective way to achieve this is by creating reusable apps – self-contained components that can be easily integrated into different projects. In this tutorial, we'll walk through the process of building a reusable app in Django using a simple example.
Step 1: Set Up Your Django Project
Assuming you have Django installed, start by creating a new project:
django-admin startproject myproject
cd myproject
Step 2: Create a Reusable App
Inside your project directory, create a new app:
python manage.py startapp myapp
Step 3: Define Models in Your Reusable App
In myapp/models.py, define the models for your app. For this example, let's create a Book model:
# myapp/models.py
from django.db import models
class Book(models.Model):
title = models.CharField(max_length=100)
author = models.CharField(max_length=50)
def __str__(self):
return self.title
Step 4: Create Views and Templates
Now, create views and templates for your app. In myapp/views.py, define a simple view to display a list of books:
# myapp/views.py
from django.shortcuts import render
from .models import Book
def book_list(request):
books = Book.objects.all()
return render(request, 'myapp/book_list.html', {'books': books})
Create a template in myapp/templates/myapp/book_list.html:
<!-- myapp/templates/myapp/book_list.html -->
<!DOCTYPE html>
<html>
<head>
<title>Book List</title>
</head>
<body>
<h1>Book List</h1>
<ul>
{% for book in books %}
<li>{{ book.title }} by {{ book.author }}</li>
{% endfor %}
</ul>
</body>
</html>
Step 5: Create URLs
Define the URLs for your app in myapp/urls.py:
# myapp/urls.py
from django.urls import path
from .views import book_list
app_name = 'myapp'
urlpatterns = [
path('books/', book_list, name='book_list'),
]
Step 6: Include the App URLs in Your Project
Include the URLs from your app in myproject/urls.py:
# myproject/urls.py
from django.contrib import admin
from django.urls import path, include
urlpatterns = [
path('admin/', admin.site.urls),
path('myapp/', include('myapp.urls')),
]
Step 7: Install and Configure Your Reusable App
To make your app truly reusable, create a setup.py file in your app's main directory:
# myapp/setup.py
from setuptools import setup, find_packages
setup(
name='myapp',
version='0.1',
packages=find_packages(),
install_requires=[
'Django',
],
)
Install your app using:
pip install -e .
Step 8: Use Your Reusable App in Other Projects
Now, you can use your reusable app in other Django projects. Add it to the INSTALLED_APPS in the project's settings.py:
# myproject/settings.py
INSTALLED_APPS = [
# ...
'myapp',
]
Run migrations and start the development server:
python manage.py makemigrations
python manage.py migrate
python manage.py runserver
Visit http://localhost:8000/myapp/books/ in your browser to see the list of books.
Congratulations! You've successfully created a reusable Django app. This modular approach enhances code organization and encourages code reuse across multiple projects, following Django's DRY principle.
