DRF , route a retrieve function to a post function - python

I have a Django rest framework API that gets a POST request and has a retrive method in the view.
I want that when the user presses the post button it will route the URL to the render created in the retrieve method of the view class.
code:
#views.py
class LocationInfoViewSet(ModelViewSet):
# Order all objects by id, reversed.
queryset = LocationInfo.objects.all().order_by('-id')
serializer_class = LocationInfoSerializer
def retrieve(self, request, *args, **kwargs):
"""
This method is used to get the last object created by the user and render a map associated with the
mission's name.
"""
data = self.queryset[0]
serialized_data = LocationInfoSerializer(data, many=False)
points = list(serialized_data.data.values())
assign_gdt1 = GeoPoint(lat=points[2], long=points[3])
assign_gdt2 = GeoPoint(lat=points[4], long=points[5])
assign_uav = GeoPoint(lat=points[6], long=points[7], elevation=points[-3])
# Geo locations from the POST request.
gdt1 = [assign_gdt1.get_lat(), assign_gdt1.get_long()]
gdt2 = [assign_gdt2.get_lat(), assign_gdt2.get_long()]
uav = [assign_uav.get_lat(), assign_uav.get_long(), assign_uav.get_elevation()]
mission_name = points[1]
try:
# Check if a file already exists in the DB.
HTMLFileInteractionWithDB.table = THREE_POINTS_TRINAGULATION
openfile = HTMLFileInteractionWithDB.return_file_from_db(mission_name=mission_name)
return render(request, openfile)
except:
# Create a new file if one does not exists.
# The main function Creates an HTML File to be rendered.
return render(request, main(gdt1, gdt2, uav,
gdt1_elev=assign_gdt1.get_elevation(),
gdt2_elev=assign_gdt2.get_elevation(),
mission_name=mission_name
)
)
mission name is a primary key, So to access to the retrieve method the user need to go to the URL line and write the mission name for the method to work.
So, how and where in my project (urls,view...) do I create this route.
Exmpale:

I'm a little confused as to the purpose of this view.
The retrieve method is correctly used when it is retrieving a specific object from the queryset list using the pk. IE, one of your LocationInfo objects. It's always a get request.
Your retrieve method is also missing the pk parameter, which is sometimes defaulted as None.
retrieve(self, request, pk=None)
If I were you, I'd create a completely separate view or viewset method/action for this.
Instead of using retrieve for this, we can create a completely new method:
from rest_framework.decorators import action
class LocationInfoViewSet(ModelViewSet):
# Order all objects by id, reversed.
queryset = LocationInfo.objects.all().order_by('-id')
serializer_class = LocationInfoSerializer
# {The rest of your methods, etc...}
#action(detail=False, methods=["post"])
def last_object_by_user(self, request, *args, **kwargs):
# your query to get the last object by your user
queryset = LocationInfo.objects.filter(created_by=request.user).latest()
# The rest of your code
This will create a new endpoint called /{name}/last_object_by_user/ that you can make post requests to.
You'd also notice that I've modified your queryset a bit. Your current queryset gives us the last LocationInfo created by any user. Did you create a field in LocationInfo that tracks who created that LocationInfo?
Here's the documentation for this: Marking extra actions for routing
Note: I did not test this code so if you copy-paste this, it might not work, but the idea is what's important.

Related

How do I specify a custom lookup field for a DRF action on a viewset?

I would like to specify a custom lookup field on the action (different from the viewset default "pk"), i.e.
#action(
methods=["GET"],
detail=True,
url_name="something",
url_path="something",
lookup_field="uuid", # this does not work unfortunately
)
def get_something(self, request, uuid=None):
pass
But the router does not generate the correct urls:
router = DefaultRouter()
router.register(r"test", TestViewSet)
router.urls
yields url:
'^test/(?P<pk>[^/.]+)/something/$'
instead of
'^test/(?P<uuid>[^/.]+)/something/$'
I do not want to change the lookup field for the whole viewset though and have been unsuccessful in finding a way to do this for the action itself after debugging through the router url generation. I did notice that model viewsets have this method:
get_extra_action_url_map(self)
but am unsure how to get it to be called to generate custom urls or if it is even relevant. Any help would be great thanks!
According to their docs you could use a regex lookup field. Their example uses a CBV instead of a request based view.
class MyModelViewSet(mixins.RetrieveModelMixin, viewsets.GenericViewSet):
lookup_field = 'uuid'
lookup_value_regex = '[0-9a-f]{32}'
This could work:
#action(
methods=["GET"],
detail=True,
url_name="something",
url_path="something",
lookup_field = 'uuid'
lookup_value_regex = '[0-9a-f]{32}'
)
def get_something(self, request, uuid=None):
pass
I think it will create much confusion for your API consumers if you have 2 different resource identification on the same resource.
You can name that action query_by_uuid or just allow them to use list_view to filter by uuid if you only want to represent the object tho. (so consumers can use /test/?uuid= to retrieve data)
But if you really want to do it, you can simply override get_object method to filter for your custom action tho:
def get_object(self):
if self.action == 'do_something':
return get_object_or_404(self.get_queryset(), uuid=self.kwargs['pk'])
return super().get_object()
Here is a bit hacky solution for generate uuid in router with detail=False.
#action(detail=False, url_path=r'(?P<uuid>[^/.]+)/do_something')
def do_something(self, request, uuid=None):
pass

Django Class Based View - How to access POST data outside of post() method

I have a CBV based on a TemplateView
It has a post(self) method to access user input.
Also, it has a template_name property which should be populated with data from post().
No Django models or forms are used here.
Attempt to extract data within post method:
# views.py
class ReturnCustomTemplateView(TemplateView):
def post(self, *args, **kwargs):
chosen_tmplt_nm = self.request.POST.get('tmplt_name')
print(chosen_tmplt_nm) # correct value.
# how do I use it outside this method? (like bellow)
template_name = chosen_tmplt_nm
... or is there any other way I can get the data from request.POST without def post()?
You can override the get_template_names() method [Django-doc] which returns an iterable (for example a list) of template names to search for when determining the name of the template, so:
class ReturnCustomTemplateView(TemplateView):
def get_template_names(self):
return [self.request.POST.get('tmplt_name')]
def post(self, *args, **kwargs):
return self.get(*args, **kwargs)
I would however advise to be careful with this: a POST request could be forged, so a hacker could make a POST request with a different template name, and thus try to obtain for example the content of the settings.py file or another file that contains sensitive data.

In Django Rest Framework, how is the object passed to a class based view from urls.py used?

I've been following the Django Rest Framework tutorial here http://www.django-rest-framework.org/tutorial/3-class-based-views/
This code in particular is intriguing:
class SnippetList(APIView):
"""
List all snippets, or create a new snippet.
"""
def get(self, request, format=None):
snippets = Snippet.objects.all()
serializer = SnippetSerializer(snippets, many=True)
return Response(serializer.data)
I know that the url function called in urls.py returns a function like entry point to the class based view when using the as_view method. Is request the object corresponding to this?
If it is, then where does the class access it and its attributes when a GET is performed? I cannot see a reference to request in the getmethod of SnippetList.
If it is not, then what does request refer to, and how does the class based view access the data in the client's request?

How to render an html template with data from view?

I am new to django. I made a form. I want that if the form is filled successfully then django should redirect to a success page showing the name entered in the form but no parameters should be present in the url itself.
I searched on the internet and the solution I got was to redirect to url with pk as a get parameter which fetches the data and shows in the view. But I don't want to pass any thing in the url itself. and some websites say that http can't redirect with post data.
Here's my views.py
class UserRegistrationView(CreateView):
model = UserForm
template_name = 'userregistration.html'
form_class = UserForm
success_url = 'success'
def get_success_url(self):
return reverse('success',kwargs = {'name' : self.object.firstName})
and here's the template to which I want to redirect:
<h2>Congratualations for registering {{name}} </h2>
Basically what I want is that if the person fill form mentioning his/her firstName as "xyz" then the redirected success page should say that "Congratulations for registering xyz"
You can use django sessions, which I believe installed by default in 1.8
Look here
# Set a session value:
request.session["fav_color"] = "blue"
# Get a session value -- this could be called in a different view,
# or many requests later (or both):
fav_color = request.session["fav_color"]
# Clear an item from the session:
del request.session["fav_color"]
You can pass your pk via session and extract your object in another view without affecting your url.
Make sure you clean up after yourself.
Let me know if more help needed.
One of the possible ways of passing data between views is via sessions. So, in your UserRegistrationView you need to override the form_valid method as shown below.
class UserRegsitrationView(CreateView):
def form_valid(self,form):
self.request.session['name'] = self.object.firstName
return super(UserRegistrationView,self).form_valid(form)
class SuccessView(TemplateView):
template_name = "success_template.html"
def get_context_data(self,**kwargs):
context = super(SuccessView,self).get_context_data(**kwargs)
context['name'] = self.request.session.get('name')
del self.request.session['name']
return context
One more thing that you can modify in your code is that you need not declare success_url if you are overriding get_success_url

how to set cookie in class based generic view

newbies to django1.6
i want to set cookie in class based generic view (Listview)
models.py
class Designation(Models.model):
title = models.CharField(max_length=50)
description = models.CharField(max_length=10000, blank=True)
views.py
class DesignationList(ListVew):
def get_queryset(self):
"""
will get 'sort_by' parameter from request,
based on that objects list is return to template
"""
col_nm = self.request.GET.get('sort_by', None)
if col_nm:
if cookie['sort_on'] == col_nm:
objects=Designation.objects.all().order_by(col_nm).reverse()
else:
cookie['sort_on'] = col_nm
objects=Designation.objects.all().order_by(col_nm)
else:
objects = Designation.objects.all().order_by('title')
//set cookie['sort_on']='title'
return objects
template
in template im iterating over objects
so initially objects display in sort_by 'title' desc.
"this values is i want to set in cookie".
in template, if user click over title,it will check in cookie
cookie['sort_on']='title'
then all objects are in asce order
if user click over description,then cookie value is replaced
cookie['sort_on']='description' and objects are in desc order..
soo,how to set cookie which i can use in whole ListView class.. ?
Thnx in advance..
In order to set/delete cookies you have to have access to the "response" object. To do so, in a class-based view, you can override "render_to_response".
Example:
class DesignationList(ListVew):
def render_to_response(self, context, **response_kwargs):
response = super(LoginView, self).render_to_response(context, **response_kwargs)
response.set_cookie('sort_on', 'title')
return response
Unless you have a very good reason, you shouldn't be using cookies, but the session framework. You can access that inside your methods with self.request.session, and it acts like a dictionary.
if col_nm:
if self.request.session.get('sort_on') == col_nm:
objects=Designation.objects.all().order_by(col_nm).reverse()
else:
self.request.session['sort_on'] = col_nm
objects=Designation.objects.all().order_by(col_nm)
etc.

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