Request and Response Objects

Django uses request and response objects to pass state through the system.

https://docs.djangoproject.com/en/3.0/ref/request-response/

Overview

• Django creates an HttpRequest (contains metadata about the request) object when a page is requested

• Django loads the appropriate view, passing the HttpRequest as the first argument to the view function

  • Each view is responsible for returning an HttpResponse object

HttpRequest objects

class HttpRequest

Attributes

HttpRequest.method

• A string representing the HTTP method used in the request.

• This is guaranteed to be uppercase.

ex)

if request.method == 'GET':
    do_something()
elif request.method == 'POST':
    do_something_else()

HttpRequest.FILES

• A dictionary-like object containing all uploaded files.

  • Each key in FILES is the name from the <input type="file" name="">.

  • Each value in FILES is an UploadedFile.

• FILES will only contain data if the request method was POST and the <form> that posted to the request had enctype="multipart/form-data".

  • Otherwise, FILES will be a blank dictionary-like object.

HttpResponse objects

class HttpResponse

• In contrast to HttpRequest objects, which are created automatically by Django, HttpResponse objects are your responsibility.

  • Each view you write is responsible for instantiating, populating, and returning an HttpResponse.

• The HttpResponse class lives in the django.http module.

HttpResponse subclasses

class HttpResponseBadRequest

• Acts just like HttpResponse but uses a 400 status code.

class HttpResponseNotFound

• Acts just like HttpResponse but uses a 404 status code.

class HttpResponseForbidden

• Acts just like HttpResponse but uses a 403 status code.

class HttpResponseNotAllowed

• Like HttpResponse, but uses a 405 status code.

• The first argument to the constructor is required: a list of permitted methods (e.g. ['GET', 'POST']).

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What is Monolithic Architecture?

:

• Advantages

  • Fast development possible since everything is in one place

• Disadvantages

  • Difficult to scale