Django - Generic View Subclassed - url Parameters - django

I need to display a detail page for a video with some other data.
For that I use DetailView that I have overridden to add some variables to the context.
Here are the code parts:
#urlconf
#...
(r'viewtube/(?P<pk>\d+)$', VideoFileDetailView.as_view()),
#...
#view
class VideoFileDetailView(DetailView):
model = VideoFile
def get_context_data(self, **kwargs):
context = super(VideoFileDetailView, self).get_context_data(**kwargs)
# context['rates'] = VideoRate.objects.filter(video=11, user=1)
return context
Here pk is the id of a video, I need to get the rates of the selected video by the current user.

It would have been useful to show the models. But I think you need to override get(), not get_context_data, as unfortunately the latter doesn't get passed the request, which you need in order to get the user. So:
def get(self, request, **kwargs):
self.object = self.get_object()
context = self.get_context_data(object=self.object)
context['rates'] = VideoRate.objects.filter(video=self.object, user=request.user)
return self.render_to_response(context)

The request should be accessible at self.request. self.request is set at the beginning of the request (in View.dispatch) and should be available any of the subclass methods.
class VideoFileDetailView(DetailView):
model = VideoFile
def get_context_data(self, **kwargs):
context = super(VideoFileDetailView, self).get_context_data(**kwargs)
context['rates'] = VideoRate.objects.filter(video=11, self.request.user)
# note that the object is available via self.object or kwargs.get("object")
return context

Related

Attibutes are 'disappearing' from CBV. Django

I am trying to build CBV with class View parent. This view takes slug of object and find that object between two django models. The functions from services.py was doing a lot of DB queries, so, I tried to reduce them by giving to FeedbackSection necessary attributes(slug, model_instance and context) and lately override them in get method.
class FeedbackSection(View):
"""
Feedback section for different objects.
This is something like 'generic' view, so I implement it that it will find
the model and feedbacks for this model by having only slug.
"""
template_name = 'feedbacks/feedback-section.html'
form_class = CreateFeedbackForm
slug = None
model_instance = None
context = None
def get(self, request, *args, **kwargs):
self.slug = kwargs.get('slug')
self.model_instance = get_model_instance(self.slug)
self.context = get_feedback_section_context(self.slug, self.form_class, self.model_instance)
return render(request, self.template_name, self.context)
#method_decorator(login_required)
def post(self, request, *args, **kwargs):
form = self.form_class(request.POST)
if form.is_valid():
# will create feedback object and update model[Advert, Company] rating.
end_feedback_post_logic(self.request.user, form, self.model_instance)
return render(request, self.template_name, self.context)
The attributes(slug, model_instance and context), when post method is in runtime are equivalent to None.
The problem is that this implementation was working fine yesterday, but today it's not.
I know I can use my functions again, but in post method. I don't want to do this. Because it will multiple DB Queries by two.
We need to override the setup method of the View class and define those attributes there.
def setup(self, request, *args, **kwargs):
self.slug = kwargs.get('slug')
self.model_instance = get_model_instance(self.slug)
self.context = get_feedback_section_context(
self.slug,
self.form_class,
self.model_instance
)
return super().setup(request, *args, **kwargs)

Show a paginated ListView and an UpdateView on the same template page

I am trying to create a Django page where something can be updated and something can be viewed in a paginated table. The model looks like this:
class CostGroup(models.Model):
name = models.CharField(max_length=200)
description = models.CharField(max_length=200)
def get_absolute_url(self):
return reverse(
'costgroup_detail',
kwargs={
'costgroup_pk': self.pk,
}
)
class Cost(models.Model):
cost_group = models.ForeignKey(CostGroup)
amount = models.DecimalField(max_digits=50, decimal_places=2)
def get_absolute_url(self):
return reverse(
'cost_detail',
kwargs={
'cost_pk': self.pk,
}
)
So the edit form is for the name and description fields of the CostGroup model and the table should show a list of the 'amounts`
I previously had it working by just having an UpdateView for the form and the table included in the form template. Now though, as I want to include pagination on the table, I need to use two views on the same page. The page I have designed should look something like this in the end:
I am not worried about the styling at the moment my main focus at the moment is getting the form and the table on the same page. In its current state the only thing that I don't have is the pagination for the table:
The view currently looks like this:
class CostDetail(UpdateView):
model = models.Cost
pk_url_kwarg = 'cost_pk'
template_name = 'main/cost_detail.html'
form_class = forms.CostDetailEditForm
success_url = reverse_lazy('cost_list')
I have a feeling that leveraging the underlying mixins that the Django CBVs use is probably the way to go but I am not sure how to begin with this.
Any help would be much appreciated
Thanks for your time
(This clarification seemed to work better as a new answer)
It looks like you're dealing with both of the tables. The object level is using CostGroup, while the List view is showing the child records from Cost linked to a CostGroup. Assuming that is true, here's how I would proceed:
class CostDetail(ModelFormMixin, ListView):
model = CostGroup # Using the model of the record to be updated
form_class = YourFormName # If this isn't declared, get_form_class() will
# generate a model form
ordering = ['id']
paginate_by = 10
template_name = 'main/cost_detail.html' # Must be declared
def get_queryset(self):
# Set the queryset to use the Cost objects that match the selected CostGroup
self.queryset = Cost.objects.filter(cost_group = get_object())
# Use super to add the ordering needed for pagination
return super(CostDetail,self).get_queryset()
# We want to override get_object to avoid using the redefined get_queryset above
def get_object(self,queryset=None):
queryset = CostGroup.objects.all()
return super(CostDetail,self).get_object(queryset))
# Include the setting of self.object in get()
def get(self, request, *args, **kwargs):
# from BaseUpdateView
self.object = self.get_object()
return super(CostDetail,self).get(request, *args, **kwargs)
# Include the contexts from both
def get_context_data(self, **kwargs):
context = ModelFormMixin.get_context_data(**kwargs)
context = ListView.get_context_data(**context)
return context
# This is the post method found in the Update View
def post(self, request, *args, **kwargs):
# From BaseUpdateView
self.object = self.get_object()
# From ProcessFormView
form = self.get_form()
self.form = form
if form.is_valid():
return self.form_valid(form)
else:
return self.form_invalid(form)
def put(self, *args, **kwargs):
return self.post(*args, **kwargs)
I haven't tried to run this, so there may be errors. Good luck!
(Remember ccbv.co.uk is your friend when digging into Class-based Views)
An app I'm working on now uses a similar approach. I start with the ListView, bring in the FormMixin, and then bring in post() from the FormView.
class LinkListView(FormMixin, ListView):
model = Link
ordering = ['-created_on']
paginate_by = 10
template_name = 'links/link_list.html'
form_class = OtherUserInputForm
#=============================================================================#
#
# Handle form input
#
def post(self, request, *args, **kwargs):
"""
Handles POST requests, instantiating a form instance with the passed
POST variables and then checked for validity.
"""
form = self.get_form()
self.form = form
if form.is_valid():
return self.form_valid(form)
else:
return self.form_invalid(form)
def put(self, *args, **kwargs):
return self.post(*args, **kwargs)
def get_success_url(self):
return reverse('links')
You may also wish to override get_object(), get_queryset(), and get_context().

How can I get 'pk' or 'id' in `get_context_data` from CBV?

How can I get 'pk' or 'id' in get_context_data from CBV DetailView?
class MyDetail(DetailView):
model = Book
template_name = 'book.html'
def get_context_data(self, **kwargs):
context = super(MyDetail, self).get_context_data(**kwargs)
context['something'] = Book.objects.filter(pk=pk)
return context
url:
url(r'^book/(?P<pk>\d+)/$', MyDetail.as_view(), name='book'),
You can get it from self.kwargs['pk'].
I'm not sure why you want to, though, since the superclass already gets the Book corresponding to that pk - that's the whole point of a DetailView.
class MyDetail(DetailView):
model = Book
template_name = 'book.html'
def get_context_data(self, **kwargs):
context = super(MyDetail, self).get_context_data(**kwargs)
context['something'] =Book.objects.filter(pk=self.kwargs.get('pk'))
return context
self.kwargs['pk'] it doesn't work in Django 2.2
in DetailView
self.object is the object that this view is displaying.
So, to access the object's fields like id or pk just self.object.id or self.object.pk
So, The answer in Django 2.2 can be like:
class MyDetail(DetailView):
model = Book
template_name = 'book.html'
def get_context_data(self, **kwargs):
context = super().get_context_data(**kwargs)
context['something'] = Book.objects.filter(pk=self.object.pk) # <<<---
return context
Django 2.2 Doc
In get_context_data you already have the object in self.object (and you can do self.object.pk). Here's what happens upstream in the class hierarchy (DetailView inherits from BaseDetailView):
class BaseDetailView(SingleObjectMixin, View):
"""
A base view for displaying a single object
"""
def get(self, request, *args, **kwargs):
self.object = self.get_object()
context = self.get_context_data(object=self.object)
return self.render_to_response(context)
Reading Django source code to understand stuff is incredibly easy.
And by the way, I am not sure you can always rely on the fact that kwargs has a 'pk' key.
In addition to getting it from self.kwargs as Daniel Roseman suggested, you can use self.get_object().pk, for example if you change your URL identifier from pk to, say, slug or something.
you can simply get it in the 'get' method, like this:
def get_context_data(self, request, pk, *args, **kwargs):
context = super(MyDetail, self).get_context_data(**kwargs)
context['something'] =Book.objects.filter(pk=self.kwargs.get('pk'))
return context
def get_context_data(self, request, pk, *args, **kwargs):
context = super(MyDetail, self).get_context_data(**kwargs)
context['something'] =Book.objects.filter(pk=self.kwargs.get('pk'))
return context
Filter returns a query set that matches the lookup parameter (pk). Since 'pk' is unique, it would return the same results as get but for performance issues, ideally you'd want to use the get method to return one single object:
def get_context_data(self, request, pk, *args, **kwargs):
context = super(MyDetail, self).get_context_data(**kwargs)
context['something'] =Book.objects.get(pk=self.kwargs.get('pk'))
return context

How to pass ForeignKey value into initial data for Django form

I have a model like this:
class Job(models.Model):
slug = models.SlugField()
class Application(models.Model):
job = models.ForeignKey(Job)
And a view like this:
class ApplicationCreateView(CreateView):
model = Application
A user will view the job object (/jobs/<slug>/), then complete the application form for the job (/jobs/<slug>/apply/).
I'd like to pass application.job.slug as the initial value for the job field on the application form. I'd also like for the job object to be put in context for the ApplicationCreateView (to tell the user what job they're applying for).
How would I go about doing this in my view?
You may be interested in CreateView page of the fantastic http://ccbv.co.uk/ In this page, you can see in one glance which member methods and variables you can use.
In your case, you will be interested to override:
def get_initial(self):
# Call parent, add your slug, return data
initial_data = super(ApplicationCreateView, self).get_initial()
initial_data['slug'] = ... # Not sure about the syntax, print and test
return initial_data
def get_context_data(self, **kwargs):
# Call parent, add your job object to context, return context
context = super(ApplicationCreateView, self).get_context_data(**kwargs)
context['job'] = ...
return context
This has not been tested at all. You may need to play with it a little. Have fun.
I ended up doing the following in a function on my class:
class ApplicationCreateView(CreateView):
model = Application
form_class = ApplicationForm
success_url = 'submitted/'
def dispatch(self, *args, **kwargs):
self.job = get_object_or_404(Job, slug=kwargs['slug'])
return super(ApplicationCreateView, self).dispatch(*args, **kwargs)
def form_valid(self, form):
#Get associated job and save
self.object = form.save(commit=False)
self.object.job = self.job
self.object.save()
return HttpResponseRedirect(self.get_success_url())
def get_context_data(self, *args, **kwargs):
context_data = super(ApplicationCreateView, self).get_context_data(*args, **kwargs)
context_data.update({'job': self.job})
return context_data

Extending class, date based generic views in django and get_context_data?

I'm trying to extend a simple date based view (using the 1.3 generic class approach) with my own mixin "BaseViewMixin":
class BaseViewMixin(object):
"""define some basic context for our views"""
model = Alert
month_format = "%m"
date_field = "date"
def get_context_data(self, **kwargs):
"""extra context"""
context = super(BaseViewMixin, self).get_context_data(**kwargs)
context["CACHE_SERVERS"] = settings.CACHE_SERVERS
return context
#method_decorator(login_required)
def dispatch(self, *args, **kwargs):
return super(BaseViewMixin, self).dispatch(*args, **kwargs)
class IndexView(BaseViewMixin, TodayArchiveView):
template_name= "index.html"
def get_context_data(self, **kwargs):
context = super(IndexView, self).get_context_data(**kwargs)
queryset = Alert.objects.default(self.day)
tickets = Alert.objects.tickets(self.day)
alert_groups = []
for item in tickets:
alert_groups.append({"ticket": item, "alerts": queryset.filter(ticket=item["ticket"])})
context["alert_groups"] = alert_groups
return context
The problem is that all of the date based things you normally get in the context are wiped out as soon as I override the get_context_data method for my IndexView class. Why is that? I would expect {{ day }}, {{ previous_day }} etc to show up in the context, as well as self. When I remove my get_context_data method all the generic date stuff works.
urls.py entry is just:
url(r'^$', IndexView.as_view(), name='index'),
This is one way to do it which allows me to reuse code. I'm still not understanding why get_context_data wipes out the TodayArchiveView context the way I define it in my original question. It seems that using the scenario below would do the same thing to my mixin but it doesn't. The ViewMixin context is preserved when calling get_context_data in DateMixin.
class ViewMixin(object):
"""define some basic context for our views"""
model = Alert
def get_context_data(self, **kwargs):
"""extra context"""
context = super(ViewMixin, self).get_context_data(**kwargs)
context["CACHE_SERVERS"] = settings.CACHE_SERVERS
return context
#method_decorator(login_required)
def dispatch(self, *args, **kwargs):
return super(ViewMixin, self).dispatch(*args, **kwargs)
class DateMixin(object):
month_format = "%m"
date_field = 'date'
def get_alert_groups(self):
none, qs, dated_items = self.get_dated_items()
day = dated_items["day"]
queryset = Alert.objects.default(day)
tickets = Alert.objects.tickets(day)
alert_groups = []
for item in tickets:
alert_groups.append({"ticket": item, "alerts": queryset.filter(ticket=item["ticket"])})
return alert_groups
def get_context_data(self, **kwargs):
context = super(DateMixin, self).get_context_data(**kwargs)
context["alert_groups"] = self.get_alert_groups()
return context
class IndexView(ViewMixin, DateMixin, TodayArchiveView):
template_name= "index.html"
Not an exact answer to your question, but considering the fact that your goal seems to be adding a certain context to more than one view a context processor might be a good solution!
The problem arise because you're inhereting from 2 classes.
context = super(IndexView, self).get_context_data(**kwargs) will initialise the context with the method from BaseViewMixin not TodayArchiveView (super walks base classes from left to right) --> context variables from TodayArchiveView will be lost.
I think you can do this:
def get_context_data(self, **kwargs):
context = super(IndexView, self).get_context_data(**kwargs)
context_day = super(BaseViewMixin, self).get_context_data(**kwargs)
context = dict(context, **context_day)
...