DetailView for single objects in Django - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ component_behavior

intermediate

What does this Django DetailView render?

Given this DetailView and URL pattern, what will the template receive as context variable?

Django

from django.views.generic.detail import DetailView
from .models import Book

class BookDetailView(DetailView):
    model = Book
    template_name = 'books/detail.html'

# URL pattern:
# path('books/<int:pk>/', BookDetailView.as_view(), name='book-detail')

A No context variable is passed to the template

B A context variable named 'object_list' containing all Book instances

C A context variable named 'book_detail' containing the Book instance with the given pk

D A context variable named 'book' containing the Book instance with the given pk

💡 Hint

Think about the default context variable name DetailView uses for the model instance.

The DetailView automatically passes the single object as a context variable named after the model in lowercase. Here, it is 'book'.

📝 Syntax

intermediate

Which option correctly overrides get_object in a DetailView?

You want to customize how the object is fetched in a DetailView. Which code snippet correctly overrides get_object?

Django

from django.views.generic.detail import DetailView
from .models import Author

class AuthorDetailView(DetailView):
    model = Author
    def get_object(self):
        # custom logic here
        pass

A

def get_object(self):
    return Author.objects.filter(pk=self.kwargs['pk'])

B

def get_object(self):
    return Author.objects.get(pk=self.kwargs['pk'])

C

def get_object(self):
    return self.model.objects.get(id=self.request.GET['id'])

D

def get_object(self):
    return self.model.get(pk=self.kwargs['pk'])

💡 Hint

Remember get_object should return a single model instance, not a queryset.

Option B correctly uses get() with pk from kwargs. Option B uses GET parameters incorrectly. Option B returns a queryset, not an object. Option B calls get on the model class incorrectly.

❓ state_output

advanced

What is the output of this DetailView with missing pk in URL?

Consider this DetailView and URL pattern. What happens if you visit '/authors/' without a pk?

Django

from django.views.generic.detail import DetailView
from .models import Author

class AuthorDetailView(DetailView):
    model = Author

# URL pattern:
# path('authors/<int:pk>/', AuthorDetailView.as_view(), name='author-detail')

A 404 Not Found error is raised

B The first Author object is shown by default

C A TypeError is raised because pk is missing

D The view redirects to the authors list page

💡 Hint

Think about what happens when the URL does not provide the required pk argument.

The URL pattern requires a pk. Without it, Django cannot resolve the URL to this view, so a 404 error occurs.

🔧 Debug

advanced

Why does this DetailView raise MultipleObjectsReturned error?

This DetailView code raises MultipleObjectsReturned. Why?

Django

from django.views.generic.detail import DetailView
from .models import Publisher

class PublisherDetailView(DetailView):
    model = Publisher
    def get_object(self):
        return Publisher.objects.get(name=self.kwargs['name'])

# URL pattern:
# path('publishers/<str:name>/', PublisherDetailView.as_view(), name='publisher-detail')

A The model Publisher does not have a 'name' field

B The URL pattern does not pass 'name' to the view

C There are multiple Publisher objects with the same name, so get() fails

D get_object should return a queryset, not a single object

💡 Hint

get() expects exactly one object. What if multiple objects match the filter?

get() raises MultipleObjectsReturned if more than one object matches the query. Here, multiple publishers share the same name.

🧠 Conceptual

expert

How to customize context data in a DetailView?

You want to add extra data to the template context in a DetailView. Which method should you override?

A get_context_data

B get_object

C dispatch

D render_to_response

💡 Hint

Think about where the context dictionary is prepared before rendering.

get_context_data allows you to add extra variables to the context passed to the template.