Django Cookies, how can I set them? - django

Question

I have a web site which shows different content based on a location
the visitor chooses. e.g: User enters in 55812 as the zip. I know what
city and area lat/long. that is and give them their content pertinent
to that area. My question is how can I store this in a cookie so that
when they return they are not required to always enter their zip code?
I see it as follows:
Set persistent cookie based on their area.
When they return read cookie, grab zipcode.
Return content based on the zip code in their cookie.
I can't seem to find any solid information on setting a cookie. Any
help is greatly appreciated.

Answer 1

Using Django's session framework should cover most scenarios, but Django also now provide direct cookie manipulation methods on the request and response objects (so you don't need a helper function).
Setting a cookie:
def view(request):
response = HttpResponse('blah')
response.set_cookie('cookie_name', 'cookie_value')
Retrieving a cookie:
def view(request):
value = request.COOKIES.get('cookie_name')
if value is None:
# Cookie is not set
# OR
try:
value = request.COOKIES['cookie_name']
except KeyError:
# Cookie is not set

Answer 2

UPDATE : check Peter's answer below for a builtin solution :
This is a helper to set a persistent cookie:
import datetime
def set_cookie(response, key, value, days_expire=7):
if days_expire is None:
max_age = 365 * 24 * 60 * 60 # one year
else:
max_age = days_expire * 24 * 60 * 60
expires = datetime.datetime.strftime(
datetime.datetime.utcnow() + datetime.timedelta(seconds=max_age),
"%a, %d-%b-%Y %H:%M:%S GMT",
)
response.set_cookie(
key,
value,
max_age=max_age,
expires=expires,
domain=settings.SESSION_COOKIE_DOMAIN,
secure=settings.SESSION_COOKIE_SECURE or None,
)
Use the following code before sending a response.
def view(request):
response = HttpResponse("hello")
set_cookie(response, 'name', 'jujule')
return response
UPDATE : check Peter's answer below for a builtin solution :

Answer 3

You could manually set the cookie, but depending on your use case (and if you might want to add more types of persistent/session data in future) it might make more sense to use Django's sessions feature. This will let you get and set variables tied internally to the user's session cookie. Cool thing about this is that if you want to store a lot of data tied to a user's session, storing it all in cookies will add a lot of weight to HTTP requests and responses. With sessions the session cookie is all that is sent back and forth (though there is the overhead on Django's end of storing the session data to keep in mind).

Answer 4

Anyone interested in doing this should read the documentation of the Django Sessions framework. It stores a session ID in the user's cookies, but maps all the cookies-like data to your database. This is an improvement on the typical cookies-based workflow for HTTP requests.
Here is an example with a Django view ...
def homepage(request):
request.session.setdefault('how_many_visits', 0)
request.session['how_many_visits'] += 1
print(request.session['how_many_visits'])
return render(request, 'home.html', {})
If you keep visiting the page over and over, you'll see the value start incrementing up from 1 until you clear your cookies, visit on a new browser, go incognito, or do anything else that sidesteps Django's Session ID cookie.

Answer 5

In addition to jujule's answer below you can find a solution that shows how to set a cookie to Class Based Views responses. You can apply this solution to your view classes that extends from TemplateView, ListView or View.
Below a modified version of jujule's persistent cookie setter method:
import datetime
from django.http import HttpResponse
def set_cookie(
response: HttpResponse,
key: str,
value: str,
cookie_host: str,
days_expire: int = 365,
):
max_age = days_expire * 24 * 60 * 60
expires = datetime.datetime.strftime(
datetime.datetime.utcnow() + datetime.timedelta(days=days_expire), "%a, %d-%b-%Y %H:%M:%S GMT",
)
domain = cookie_host.split(":")[0]
response.set_cookie(
key,
value,
max_age=max_age,
expires=expires,
domain=domain,
secure=False,
)
And sample class based view example that adds a cookie using persistent cookie setter
class BaseView(TemplateView):
template_name = "YOUR_TEMPLATE_FILE_PATH"
def get(self, request, *args, **kwargs):
response = super().get(request, *args, **kwargs)
set_cookie(
response=response,
key="COOKIE_KEY",
value="COOKIE_VALUE",
cookie_host=request.get_host(),
days_expire=7,
)
return response