Django existing cookie is not updating - django

What i am trying to do is updating the existing django cookie that already exist. I am creating a add to cart functionality but unable to add more items in existing cookie. Any help would be praise-able.
My code is:
def AddToCart(request):
id = request.POST.get('id')
product = Product.objects.get(pk=id)
response = render(request,'index.html')
if request.COOKIES.get('product'):
request.COOKIES['product'] = {'name':product.name,'price':product.price,'img':product.image.url}
else:
response.set_cookie('product',{'name':product.name,'price':product.price,'img':product.image.url},
max_age= 14 * 24 * 60 * 60)
return response

Using request.COOKIES['product'] = .... sets the product value only in the current request context ( or maybe a copy of the COOKIES dict, not sure really), so it won't set the cookie on the client side (response), and on the next request it will be overridden by the cookie it gets from the client response (which is the cookie prior to using request.COOKIES['product'] = ....).
So first you need to replace: request.COOKIES['product'] = ... by response.set_cookie("product", ...) for the value to change.
This will solve your cookie setting problem only, but not appending multiple products to your cookie.
For that i suggest you use sessions instead, as they are easier to use when it comes to manipulating data structures like dicts and arrays, for eg: on the client-side cookies approach, you need to write your own serialization to manipulate a dict/array stored in the cookie, example here: https://stackoverflow.com/a/2383482
Also you can refer to this answer to tell if you need cookie or db based sessions:
https://stackoverflow.com/a/18240232/4724196

Related

How do I check if a user has entered the URL from another website in Django?

I want an effect to be applied when a user is entering my website. So therefore I want to check for when a user is coming from outside my website so the effect isnt getting applied when the user is surfing through different urls inside the website, but only when the user is coming from outside my website
You can't really check for where a user has come from specifically. You can check if the user has just arrived on your site by setting a session variable when they load one of your pages. You can check for it before you set it, and if they don't have it, then they have just arrived and you can apply your effect. There's some good examples of how sessions work here: https://developer.mozilla.org/en-US/docs/Learn/Server-side/Django/Sessions
There's a couple of ways to handle this. If you are using function based views, you can just create a separate util function and include it at the top of every page, eg,
utils.py
def first_visit(request):
"""returns the answer to the question 'first visit for session?'
make sure SESSION_EXPIRE_AT_BROWSER_CLOSE set to False in settings for persistance"""
if request.session['first_visit']:
#this is not the first session because the session variable is used.
return False
else:
#This is the first visit
...#do something
#set the session variable so you only do the above once
request.session[first_visit'] = True
return True
views.py
from utils.py import first_visit
def show_page(request):
first_visit = first_visit(request)
This approach gives you some control. For example, you may not want to run it on pages that require login, because you will already have run it on the login page.
Otherwise, the best approach depends on what will happen on the first visit. If you want just to update a template (eg, perhaps to show a message or run a script on th epage) you can use a context processor which gives you extra context for your templates. If you want to interrupt the request, perhaps to redirect it to a separate page, you can create a simple piece of middleware.
docs for middleware
docs for context processors
You may also be able to handle this entirely by javascript. This uses localStorage to store whether or not this is the user's first visit to the site and displays the loading area for 5 seconds if there is nothing in localStorage. You can include this in your base template so it runs on every page.
function showMain() {
document.getElementByID("loading").style.display = "none";
document.getElementByID("main").style.display = "block";
}
const secondVisit = localStorage.getItem("secondVisit");
if (!secondVisit) {
//show loading screen
document.getElementByID("loading").style.display = "block";
document.getElementByID("main").style.display = "none";
setTimeout(5000, showMain)
localStorage.setItem("secondVisit", "true" );
} else {
showMain()
}

How to make filtering non model data in flask-admin

I have to make dashboard like view in flask-admin that will use data retrieved from external API. I have already written a functions that get date ranges and return data from that range. I should use BaseView probably but I don't know how to actually write it to make filters work. This is example function that i have to use: charts = generate_data_for_dashboard('164', '6423FACA-FC71-489D-BF32-3A671AB747E3', '2018-03-01', '2018-09-01'). Those params should be chosen from 3 different dropdowns. So far I know only how to render views with pre coded data like this :
class DashboardView(BaseView):
kwargs = {}
#expose('/', methods=('GET',))
def statistics_charts(self):
user = current_user
company = g.company
offices = Office.query.filter_by(company_id=company.id)
self.kwargs['user'] = user
self.kwargs['company'] = company
charts = generate_data_for_dashboard('164', '6423FACA-FC71-489D-BF32-3A671AB747E3', '2018-03-01', '2018-09-01')
self.kwargs['chart1'] = charts[0]
self.kwargs['chart2'] = charts[1]
return self.render('stats/dashboard.html', **self.kwargs)
But I need some kind of form to filter it. In addition date filter dropdown should have dynamic options : current_week, last_week, current_month, last_month, last_year. Don't know where to start.
You should use WTForms to build a form. You then have to decide if you want the data to be fetched on Submit or without a reload of the page. In the former case, you can just return the fetched information on the response page in your statistics_charts view. But if you want the data to update without a reload, you'll need to use JavaScript to track the form field changes, send the AJAX request to the API, and then interpret the resulting JSON and update your dashboard graphs and tables as needed.
I have not used it, but this tutorial says you can use Dash for substantial parts of this task, while mostly writing in Python. So that could be something to check out. There is also flask_jsondash which might work for you.

Storing in Django Sessions

I have a ReactJS component inside a Django template, where a user clicks on a checkout button, posts the item_code and gets redirected to checkout:
onCheckout = () => {
fetch("/onCheckout/", {
method: "POST",
body: JSON.stringify({'item': this.props.item_info.code})
}).then(window.location.replace("/checkout"))
}
A Django view receives the request and stores it in a session.
def onCheckout(request):
if request.method == "POST":
items = request.session.get('items', [])
new_item = json.loads(request.body.decode('utf-8'))['item']
items.append(new_item)
request.session['items'] = items
I am having a issue with storing data in the session. After the first item gets stored correctly in the array, and I then checkout on a second item, the items array starts acting up:
(Pdb) items
['15130BC.ZZ.8042BC.01']
(Pdb) new_item
'5213G-001'
(Pdb) items
['15130BC.ZZ.8042BC.01']
(Pdb) items
['5213G-001']
If I try to access request.session['item'] from any other view function, I get a KeyError.
I am fairly new to Django, any help would be appreciated. Also, I would like to know if there are better alternatives to accomplish the above.
Sessions Config
settings.SESSION_ENGINE = 'django.contrib.sessions.backends.db'
settings.SESSION_CACHE_ALIAS = 'default'
settings.CACHES = {'default': {'BACKEND': 'django.core.cache.backends.locmem.LocMemCache'}}
Some reading on change detection for Django sessions: https://docs.djangoproject.com/en/2.0/topics/http/sessions/#when-sessions-are-saved
Based on your code, it appears to me that the change detection should happen. However, let's try to brute force this, can you add the following line as the last line of your code: request.session.modified = True - see if this fixes your issue?
Update: some basic checks
Can you verify the following
Check if your db backend is configured priestly
If you want to use a database-backed session, you need to add 'django.contrib.sessions' to your INSTALLED_APPS setting. Once you have configured your installation, run manage.py migrate to install the single database table that stores session data.
Check if your session Middleware is enabled
Sessions are implemented via a piece of middleware. The default settings.py created by django-admin startproject has SessionMiddleware activated. To enable session functionality, edit the MIDDLEWARE_CLASSES setting and make sure it contains 'django.contrib.sessions.middleware.SessionMiddleware'.
Update 2: Test the session
Maybe modify a style existing endpoint as follows and see if you are able to store values and persist them in session :
test_keys = request.session.get('test_keys', [])
test_keys.append(random.randint())
request.session['test_keys'] = test_keys
return Response(request.session.get('test_keys', []))
You should see that each time you hit the api, you get a list with one new integer in it in addition to all past values. Lmk how this goes.

store a list in request.session in one view and retrieve it in another view django

I have a huge list that will be generated dynamically from a csv file in a django view, but i had a requirement to use that list in the next view, so i thought to give a try on django sessions
def import_products(request):
if request.method == 'POST':
if request.FILES:
csv_file_data = ...........
total_records = [row for row in csv_file_data]
request.session['list_data'] = total_records
# total_records is `list of lists` of length more than 150
# do some processing with the list and render the page
return render_to_response('product/import_products.html')
def do_something_with_csv_data_from_above_view(request):
data = request.session['list_data']
# do some operations with list and render the page
return render_to_response('website/product/success.html',
So as mentioned in the above, i need to use the total_records huge list in the do_something_with_csv_data_from_above_view view and delete the session by storing it in another variable
So actually how to implement/use exactly the sessions concept(i have read the django docs but could n't able to get the exact concept)
In my case,
When a user tries to upload the csv file each time, i am reading the data and storing
the data as list to session
==> Is this the right way to do so ? also i want to store the session variable in
database concept
Because the list was huge, i need to delete it for sure in the next view when i
copied it in to another variable
Am i missing anything, can anyone please implement exact code for my above scenario ?
You have two options:
Client side RESTful - This is a RESTful solution but may require a bit more work. You can retrieve the data in the first request to the client and after selecting you can send the selected rows back to the server for processing, CSV etc.
Caching: In the first request you can cache your data on the server using a django file system or memcached. In the second request use the cache key (which would be the user session key + some timestamp + whatever else) to fetch the data and store in the db.
If it's a lot of data option 2 may be better.

Django: Passing a request directly (inline) to a second view

I'm trying to call a view directly from another (if this is at all possible). I have a view:
def product_add(request, order_id=None):
# Works. Handles a normal POST check and form submission and redirects
# to another page if the form is properly validated.
Then I have a 2nd view, that queries the DB for the product data and should call the first one.
def product_copy_from_history(request, order_id=None, product_id=None):
product = Product.objects.get(owner=request.user, pk=product_id)
# I need to somehow setup a form with the product data so that the first
# view thinks it gets a post request.
2nd_response = product_add(request, order_id)
return 2nd_response
Since the second one needs to add the product as the first view does it I was wondering if I could just call the first view from the second one.
What I'm aiming for is just passing through the request object to the second view and return the obtained response object in turn back to the client.
Any help greatly appreciated, critism as well if this is a bad way to do it. But then some pointers .. to avoid DRY-ing.
Thanx!
Gerard.
My god, what was I thinking. This would be the cleanest solution ofcourse:
def product_add_from_history(request, order_id=None, product_id=None):
""" Add existing product to current order
"""
order = get_object_or_404(Order, pk=order_id, owner=request.user)
product = Product.objects.get(owner=request.user, pk=product_id)
newproduct = Product(
owner=request.user,
order = order,
name = product.name,
amount = product.amount,
unit_price = product.unit_price,
)
newproduct.save()
return HttpResponseRedirect(reverse('order-detail', args=[order_id]) )
A view is a regular python method, you can of course call one from another giving you pass proper arguments and handle the result correctly (like 404...). Now if it is a good practice I don't know. I would myself to an utiliy method and call it from both views.
If you are fine with the overhead of calling your API through HTTP you can use urllib to post a request to your product_add request handler.
As far as I know this could add some troubles if you develop with the dev server that comes with django, as it only handles one request at a time and will block indefinitely (see trac, google groups).