Chapter 6: Django Views

6.1 Function Views

Basic Function Views

In Django, views are Python functions that handle HTTP requests and return HTTP responses. Function views are the simplest form of views.

A basic function view example:

from django.http import HttpResponse

def hello(request):
    return HttpResponse("Hello, World!")

This simple view function takes an HttpRequest object as a parameter and returns an HttpResponse object.

HttpRequest and HttpResponse

The HttpRequest object contains all HTTP request information sent by the client, including:

• request.method: HTTP method (GET, POST, etc.)
• request.GET: URL parameters
• request.POST: POST data
• request.COOKIES: Cookie information
• request.META: HTTP header information

The HttpResponse object is used to build HTTP responses returned to the client:

from django.http import HttpResponse

def my_view(request):
    # Create a simple HTTP response
    response = HttpResponse("Hello, World!")
    
    # Set HTTP headers
    response['Content-Type'] = 'text/plain'
    
    return response

View Decorators

Django provides many built-in decorators to enhance view functionality:

from django.contrib.auth.decorators import login_required
from django.views.decorators.http import require_http_methods

# Restrict HTTP methods
@require_http_methods(["GET", "POST"])
def my_view(request):
    if request.method == 'GET':
        return HttpResponse("GET request")
    elif request.method == 'POST':
        return HttpResponse("POST request")

# Require user login
@login_required
def protected_view(request):
    return HttpResponse(f"Hello, {request.user.username}!")

Error Handling

Django provides exception classes to handle common HTTP errors:

from django.http import HttpResponse, Http404
from django.core.exceptions import PermissionDenied

def article_detail(request, article_id):
    try:
        # Try to get the article
        article = Article.objects.get(id=article_id)
    except Article.DoesNotExist:
        # Raise 404 error
        raise Http404("Article does not exist")
    
    # Check permissions
    if not request.user.has_perm('app.view_article'):
        raise PermissionDenied("You don't have permission to view this article")
    
    return HttpResponse(f"Article: {article.title}")

6.2 Class-Based Views

View Base Class

Django provides class-based views (CBV), which are more flexible and reusable than function views:

from django.views import View
from django.http import HttpResponse

class MyView(View):
    def get(self, request):
        return HttpResponse("GET request")
    
    def post(self, request):
        return HttpResponse("POST request")

Generic View Concept

Django provides many generic view classes to handle common web development tasks, such as displaying object lists, detail pages, etc.

TemplateView Example

TemplateView is used to render templates:

from django.views.generic import TemplateView

class HomePageView(TemplateView):
    template_name = "home.html"
    
    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        context['latest_articles'] = Article.objects.all()[:5]
        return context

Inheritance and Mixins

Django's class-based views support multiple inheritance, and you can use Mixin classes to add functionality:

from django.contrib.auth.mixins import LoginRequiredMixin
from django.views.generic import ListView

class ProtectedListView(LoginRequiredMixin, ListView):
    login_url = '/login/'
    redirect_field_name = 'redirect_to'

6.3 Generic Views in Detail

ListView

ListView is used to display object lists:

from django.views.generic import ListView
from .models import Article

class ArticleListView(ListView):
    model = Article
    template_name = 'articles/article_list.html'
    context_object_name = 'articles'
    paginate_by = 10  # Display 10 items per page

DetailView

DetailView is used to display detailed information for a single object:

from django.views.generic import DetailView
from .models import Article

class ArticleDetailView(DetailView):
    model = Article
    template_name = 'articles/article_detail.html'
    context_object_name = 'article'

CreateView

CreateView is used to create new objects:

from django.views.generic import CreateView
from .models import Article
from .forms import ArticleForm

class ArticleCreateView(CreateView):
    model = Article
    form_class = ArticleForm
    template_name = 'articles/article_form.html'
    success_url = '/articles/'

UpdateView

UpdateView is used to update existing objects:

from django.views.generic import UpdateView
from .models import Article

class ArticleUpdateView(UpdateView):
    model = Article
    fields = ['title', 'content']
    template_name = 'articles/article_form.html'
    success_url = '/articles/'

DeleteView

DeleteView is used to delete objects:

from django.views.generic import DeleteView
from .models import Article
from django.urls import reverse_lazy

class ArticleDeleteView(DeleteView):
    model = Article
    template_name = 'articles/article_confirm_delete.html'
    success_url = reverse_lazy('article_list')

Complete CRUD Example

Here's a complete blog article CRUD example:

# views.py
from django.views.generic import ListView, DetailView, CreateView, UpdateView, DeleteView
from django.urls import reverse_lazy
from .models import Article
from .forms import ArticleForm

class ArticleListView(ListView):
    model = Article
    template_name = 'articles/article_list.html'
    context_object_name = 'articles'
    ordering = ['-created_at']

class ArticleDetailView(DetailView):
    model = Article
    template_name = 'articles/article_detail.html'
    context_object_name = 'article'

class ArticleCreateView(CreateView):
    model = Article
    form_class = ArticleForm
    template_name = 'articles/article_form.html'
    success_url = reverse_lazy('article_list')

class ArticleUpdateView(UpdateView):
    model = Article
    form_class = ArticleForm
    template_name = 'articles/article_form.html'
    success_url = reverse_lazy('article_list')

class ArticleDeleteView(DeleteView):
    model = Article
    template_name = 'articles/article_confirm_delete.html'
    success_url = reverse_lazy('article_list')

Corresponding URL configuration:

# urls.py
from django.urls import path
from . import views

urlpatterns = [
    path('articles/', views.ArticleListView.as_view(), name='article_list'),
    path('articles/<int:pk>/', views.ArticleDetailView.as_view(), name='article_detail'),
    path('articles/new/', views.ArticleCreateView.as_view(), name='article_create'),
    path('articles/<int:pk>/edit/', views.ArticleUpdateView.as_view(), name='article_update'),
    path('articles/<int:pk>/delete/', views.ArticleDeleteView.as_view(), name='article_delete'),
]

Summary

Django views are core components for handling user requests:

1. ✅ Function views are suitable for simple logic, easy to understand and implement
2. ✅ Class views provide better code reuse and organization
3. ✅ Generic views greatly reduce repetitive code
4. ✅ Decorators and Mixins enhance view functionality
5. ✅ Complete CRUD operation support

Choosing the right view type appropriately can improve development efficiency and code quality.

Next

We will learn how to use generic views and custom template tags to build more complex web applications.

7.1 Template Basics →

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