View decorators (require_GET, require_POST) in Django - Step-by-Step Execution

Concept Flow - View decorators (require_GET, require_POST)

HTTP Request Received

↓

Check HTTP Method

↓

Call View

↓

Return 405 Method Not Allowed

↓

Response

The decorator checks the HTTP method of the request. If it matches (GET or POST), it calls the view. Otherwise, it returns a 405 error.

Execution Sample

Django

@require_GET
def my_view(request):
    return HttpResponse('Hello GET')

This code only allows GET requests to reach the view; other methods get a 405 error.

Execution Table

Step	HTTP Method	Decorator Check	Action	Response
1	GET	require_GET passes	Call my_view	HttpResponse with 'Hello GET'
2	POST	require_GET fails	Return 405 Method Not Allowed	405 Error
3	GET	require_POST fails	Return 405 Method Not Allowed	405 Error
4	POST	require_POST passes	Call my_view	HttpResponse with 'Hello POST'

💡 Execution stops when the HTTP method does not match the decorator, returning 405 error.

Variable Tracker

Variable	Start	After Step 1	After Step 2	After Step 3	After Step 4
HTTP Method	None	GET	POST	GET	POST
Decorator Check Result	None	Pass	Fail	Fail	Pass
Response	None	'Hello GET'	405 Error	405 Error	'Hello POST'

Key Moments - 2 Insights

Why does a POST request get a 405 error when using @require_GET?

Because the decorator checks if the request method is GET. If not, it returns 405 as shown in execution_table row 2.

Can @require_POST allow GET requests to reach the view?

No, @require_POST only allows POST requests. GET requests cause a 405 error as shown in execution_table row 3.

Visual Quiz - 3 Questions

Look at the execution_table, what response does a GET request get with @require_GET?

A 405 Method Not Allowed

B HttpResponse with 'Hello GET'

C Redirect to another page

D Empty response

💡 Hint

Check execution_table row 1 under Response column.

At which step does the decorator return a 405 error for a POST request with @require_GET?

A Step 1

B Step 3

C Step 2

D Step 4

💡 Hint

Look at execution_table row 2 where HTTP Method is POST and Decorator Check fails.

If you change @require_GET to @require_POST, what happens to GET requests?

A They get a 405 error

B They redirect to POST method

C They pass and call the view

D They get a 404 error

💡 Hint

See execution_table row 3 where GET with require_POST fails and returns 405.

Concept Snapshot

Use @require_GET or @require_POST to limit views to only GET or POST requests.
If the request method does not match, Django returns a 405 Method Not Allowed error.
This helps protect views from unwanted HTTP methods.
Syntax: @require_GET\ndef view(request): ...
Only requests with GET method reach the view function.

Full Transcript

View decorators like require_GET and require_POST check the HTTP method of incoming requests before calling the view function. If the method matches the decorator, the view runs and returns a response. If not, Django returns a 405 Method Not Allowed error. For example, @require_GET only allows GET requests. POST or other methods get blocked with 405. This protects views from handling unexpected methods. The execution table shows how requests with different methods are handled step-by-step. Variable tracking shows how the HTTP method and response change. Common confusions include why POST requests fail with @require_GET and vice versa. The visual quiz tests understanding of these behaviors. Overall, these decorators help control which HTTP methods your Django views accept.

Practice

1. What is the main purpose of the @require_GET decorator in Django views?

easy

A. To allow only GET requests to access the view

B. To allow only POST requests to access the view

C. To allow both GET and POST requests to access the view

D. To disable all HTTP requests to the view

Solution

1. Step 1: Understand the decorator's role

   The @require_GET decorator restricts the view to accept only GET requests.

2. Step 2: Compare with other decorators

   Unlike @require_POST which allows only POST, @require_GET is specific to GET requests.

3. Final Answer:

   To allow only GET requests to access the view -> Option A

4. Quick Check:

   @require_GET = allows GET only [OK]

Hint: Remember GET is for reading data, require_GET allows only that [OK]

Common Mistakes:

• Confusing @require_GET with @require_POST
• Thinking it allows all request types
• Assuming it disables the view

2. Which of the following is the correct way to import and use the @require_POST decorator in a Django view?

easy

A. from django.views.decorators import require_POST

@require_POST
def my_view(request):
pass

B. from django.views.decorators.http import require_GET

@require_POST
def my_view(request):
pass

C. from django.http import require_POST

@require_POST
def my_view(request):
pass

D. from django.views.decorators.http import require_POST

@require_POST
def my_view(request):
pass

Solution

1. Step 1: Identify the correct import path

   The @require_POST decorator is imported from django.views.decorators.http.

2. Step 2: Check usage syntax

   The decorator is applied directly above the view function with @require_POST.

3. Final Answer:

   from django.views.decorators.http import require_POST @require_POST def my_view(request): pass -> Option D

4. Quick Check:

   Correct import and decorator usage = from django.views.decorators.http import require_POST @require_POST def my_view(request): pass [OK]

Hint: Import from django.views.decorators.http for both decorators [OK]

Common Mistakes:

• Importing from wrong module like django.http
• Using @require_GET instead of @require_POST
• Missing the decorator above the function

3. Consider this Django view code snippet:

from django.views.decorators.http import require_GET
from django.http import HttpResponse

@require_GET
def sample_view(request):
    return HttpResponse('Hello GET')

What will happen if a POST request is sent to sample_view?

medium

A. The view will return 'Hello GET' response

B. The view will raise a 405 Method Not Allowed error

C. The view will ignore the POST and treat it as GET

D. The view will crash with a server error

Solution

1. Step 1: Understand @require_GET behavior

   The decorator allows only GET requests; other methods are blocked.

2. Step 2: Check response to disallowed methods

   When a POST request is sent, Django returns a 405 Method Not Allowed error automatically.

3. Final Answer:

   The view will raise a 405 Method Not Allowed error -> Option B

4. Quick Check:

   @require_GET blocks POST with 405 error [OK]

Hint: require_GET blocks non-GET with 405 error [OK]

Common Mistakes:

• Assuming POST is accepted and returns normal response
• Thinking it crashes the server
• Believing it silently converts POST to GET

4. You have this Django view:

from django.views.decorators.http import require_POST
from django.http import HttpResponse

@require_POST
def submit_data(request):
    return HttpResponse('Data submitted')

When testing, you accidentally send a GET request and get an error. What is the most likely cause?

medium

A. The @require_POST decorator blocks GET requests causing a 405 error

B. The HttpResponse is not imported correctly

C. The view is missing a return statement

D. The view function name is invalid

Solution

1. Step 1: Analyze decorator effect on request methods

   The @require_POST decorator allows only POST requests and blocks others.

2. Step 2: Understand error cause on GET request

   Sending a GET request triggers a 405 Method Not Allowed error because GET is disallowed.

3. Final Answer:

   The @require_POST decorator blocks GET requests causing a 405 error -> Option A

4. Quick Check:

   @require_POST blocks GET with 405 error [OK]

Hint: GET requests fail on @require_POST with 405 error [OK]

Common Mistakes:

• Thinking missing return causes error
• Assuming HttpResponse import issue
• Blaming function name for HTTP method errors

5. You want a Django view to accept only POST requests but also want to add a custom message when a GET request is made instead of the default 405 error. Which approach correctly combines @require_POST with custom handling?

hard

A. Manually check request.method inside the view and return custom response without @require_POST

B. Use @require_POST and add a try-except block inside the view to catch MethodNotAllowed

C. Use @require_POST and catch the 405 error globally in middleware

D. Use @require_GET instead and handle POST requests manually

Solution

1. Step 1: Understand @require_POST behavior

   The @require_POST decorator returns an HttpResponseNotAllowed (405) directly without calling the view or raising an exception.

2. Step 2: Combine with custom handling

   To customize the 405 response while using the decorator, implement middleware that checks response.status_code == 405 in process_response and returns a custom message.

3. Final Answer:

   Use @require_POST and catch the 405 error globally in middleware -> Option C

4. Quick Check:

   @require_POST + middleware process_response for custom 405 [OK]

Hint: Middleware process_response customizes decorator's 405 response [OK]

Common Mistakes:

• Manually checking method without decorator (doesn't combine)
• Try-except in view (view not executed)
• Using @require_GET when POST is needed