I'm trying to define a variable in my view like this:
class PostMessageView(LoginRequiredMixin, generic.TemplateView):
url_redirect = None
def post(self, request, *args, **kwargs):
return redirect(self.url_redirect)
I know this is not the good way, and there are build-in classes for that, but my problem is not here. My problem is about pure Python (I guess). If I make a descendant, I can do it like that, it works:
class ContactDetailView(PostMessageView):
template_name = 'my_home/contact_detail.html'
url_redirect = 'my_profile_contact_detail'
My problem is when I want to change url_redirect with a dynamic value, like:
class ContactDetailView(PostMessageView):
template_name = 'my_home/contact_detail.html'
def get_context_data(self, **kwargs):
self.url_redirect = self.request.build_absolute_uri(self.request.path)
Then I get argument of type 'NoneType' is not iterable because, I guess, self.url_redirect doesn't overwrite url_redirect.
How to do it properly in Python?
You can use a property for this:
class ContactDetailView(PostMessageView):
template_name = 'my_home/contact_detail.html'
#property
def url_redirect(self):
return self.request.build_absolute_uri(self.request.path)
This url_redirect method essentially acts like an attribute of the class. Using the decorator version like this will make it a getter only. You can use property as a method instead, if you wanted to make a setter as well.
The issue is that get_context_data() is not called as it should be called by your post() method.
This should work:
def post(self, request, *args, **kwargs):
self.get_context_data()
return redirect(self.url_redirect)
However, get_context_data() is supposed to return a dictionary of data to pass to the template, it is not supposed alter the object state.
Related
It's an example that's as similar as possible, and it's not exactly the same as the actual code.
But I believe it's easy to understand.
class Fruits:
...
def get_sample_data(self, df):
...
data = {
'put_file_attachment': >here<,
}
...
class DataInputForm(forms.Form):
attachment = forms.FileField()
class MyView(FormView):
template_name = 'view.html'
form_class = DataInputForm
def get_success_url(self):
return str(
reverse_lazy("milk")
)
def post(self, request, *args, **kwargs):
get_file = request.FILES.get('attachment')
...
k = Fruits()
k.load_data()
return self.render_to_response(context)
I would like to bring the attachment(In fact, get_file) that the user attached to the web class Fruits's >here<
In other words, I would like to save the file(get_file) in DB column (put_file_attachment) by the user's attachment. How can I get a value passed to a request from another class to another class?
I tried to get 'get_file' by creating a MyView object in the Fruit class, but it doesn't work.
Is that possible in this structure or Am I not understanding the concept of request??
The variable must be explicitly passed to the class for it to be available. It's currently in a different scope, so it won't be available.
So, either refactor your Fruits class to take your file as an argument to your constructor (ie, __init__), or pass it in some other way, such as a parameter to your load_data method.
More generally speaking I want add a custom admin Panel to list some related content. To lookup this related content I need to pass the current instance of the model or at least its ID to this panel. How can I do that within these lists in which these admin panels are noted?
Here is my specific example of an ArtistPage. In the editor I would like to add a panel to list WorkPages that are related to this ArtistPage:
from wagtail.models import Page
class ArtistPage(Page):
# ...
content_panels = [
# ...
ListWorksPanel(artist=self), # This doesn’t work
]
The panel itself is defined like that, mostly copied from the HelpPanel:
from wagtail.admin.panels import Panel
class ListWorksPanel(Panel):
def __init__(self, artist="", template="admin/list_works_panel.html", **kwargs,):
super().__init__(**kwargs)
self.artist = artist
self.template = template
def clone_kwargs(self):
kwargs = super().clone_kwargs()
del kwargs["help_text"]
kwargs.update(
artist=self.artist,
template=self.template,
)
return kwargs
class BoundPanel(Panel.BoundPanel):
def __init__(self, panel, instance, request, form):
super().__init__(panel, instance, request, form)
self.template_name = self.panel.template
self.artist = self.panel.artist
This is more a general Python question, I think. I know how to pass "self" in functions. But how does that work here with this class as element of a list? I reckon that the __init__() method of the ArtistPage is the way to go, but I cannot figure out how exactly.
What is the pythonic way of passing "self" to another class?
Update (Solution):
Following #gasman’s aswer, I just added the get_context_data method to the BoundPanel class. The works are accessible in the template of the panel now!
class ListWorksPanel(Panel):
def __init__(self, artist="", template="admin/list_works_panel.html", **kwargs,):
super().__init__(**kwargs)
self.artist = artist
self.template = template
def clone_kwargs(self):
kwargs = super().clone_kwargs()
del kwargs["help_text"]
kwargs.update(
artist=self.artist,
template=self.template,
)
return kwargs
class BoundPanel(Panel.BoundPanel):
def __init__(self, panel, instance, request, form):
super().__init__(panel, instance, request, form)
self.template_name = self.panel.template
self.artist = self.panel.artist
def get_context_data(self, parent_context):
context = super().get_context_data(parent_context)
context['works'] = self.instance.works.all() # exactly what I needed
return context
The ArtistPage instance is passed to BoundPanel.__init__ as the keyword argument instance. All code that deals with an individual ArtistPage needs to be written inside the BoundPanel class.
When you write ListWorksPanel() as part of a content_panels definition, you're creating a ListWorksPanel instance that then becomes part of the definition of the ArtistPage class. At this point in the code, no actual instance of ArtistPage exists, so there's no self to refer to. Effectively, there's a single ListWorksPanel object shared by all ArtistPage instances that will ever be created.
When the time comes to render the edit form for an individual page, Wagtail calls get_bound_panel on the ListWorksPanel object, passing the page instance along with the form and request objects. (The full process is explained here.) This returns an instance of BoundPanel, which is a template component that performs the final rendering. In this case, you probably want to define a get_context_data method on BoundPanel that does something like context['works'] = self.instance.works.all() - this will then make the variable works available on the template.
I need to pass id from the url slug. I am using generic views. This is my code for urls.py:
path('category/<int:pk>/details/',
CategoryDetailView.as_view(),
name='category-details'),
and I need to pass the <int:pk> value into views.py, so I can filter my queryset with this id.
My views.py code:
class CategoryDetailView(DetailView):
model = Category
def get_context_data(self, *, object_list=Expense.objects.get_queryset(), **kwargs):
queryset = object_list
return super().get_context_data(
summary_per_year_month = summary_per_year_month(queryset.filter(category_id= <int:pk> ))
)
You can access values from the URL in self.kwargs.
queryset.filter(category_id=self.kwargs['pk'])
Note that your get_context_data is the other way round than normal. Typically, you call super() and then add to the context dict. It looks like your way will work, but it will seem odd to other Django users. You could try writing it as follows:
def get_context_data(self, **kwargs):
context = super().get_context_data(**kwargs)
queryset=Expense.objects.get_queryset()
context['summary_per_year_month'] = summary_per_year_month(queryset.filter(category_id=self.kwargs['pk']))
return context
Yes, the path parameters are stored in self.kwargs, a dictionary that maps the name of the parameter to the value. So you can make use of:
class CategoryDetailView(DetailView):
model = Category
def get_context_data(self, *args, **kwargs):
summary=summary_per_year_month(
Expense.objects.filter(category_id=self.kwargs['pk'])
)
return super().get_queryset(*args, **kwargs, summary_per_year_month=summary)
You use self.kwargs.get('pk').
class CategoryDetailView(DetailView):
model = Category
def get_context_data(self, *, object_list=Expense.objects.get_queryset(), **kwargs):
queryset = object_list
return super().get_context_data(
summary_per_year_month = summary_per_year_month(queryset.filter(category_id=self.kwargs.get('pk')))
)
Something that really helped me learn Django was to add breakpoints (pdb) in my code, then run dir() on each object I came across.
For example, dir(self) will tell you what properties and methods 'self' has (ie, kwargs, model, request, etc). Then you can start experimenting around with these properties: self.kwargs, self.request, self.model, etc, see what they return.
Soon enough, you would find out that self.kwargs returns a dictionary of arguments that includes 'pk', which you can access using get(). That's how you can access 'pk'.
To me, this simple trick unlocked most of my understanding of Django and python.
I have been working on this all day.
I am trying to write custom permission for class views to check if user is in a certain group of permissions.
def rights_needed(reguest):
if request.user.groups.filter(Q(name='Admin')).exists():
pass
else:
return HttpResponseRedirect('/account/log-in/')
#method_decorator(rights_needed, name='dispatch')
class AdminView(CreateView):
model = Admin
form_class = AdminForm
def get_template_names(self):
return 'clinic/visitform_list.html'
Could help me know how I can achieve this? Or an easier way around it?
I also tried this (code inside AdminView class):
def dispatch(self, request):
if request.user.groups.filter(Q(name='Admin')).exists():
return super().dispatch(*args, **kwargs)
else:
return HttpResponseRedirect('/account/log-in/')
A decorator is a function that takes a function (a view in this case), and returns another function (a view in this case). At the moment your rights_needed looks like a regular view - it’s returning a response not a function.
Django comes with a user_passes_test method that makes it easy to create decorators like this. Since you are using class based views, it would be even easier to use the UserPassesTest mixin.
Your test function for the mixin would be:
def test_func(self):
return self.request.user.groups.filter(Q(name='Admin')).exists()
I know that there are several generic views like ListView, DetailView, or simply View.
The thing is can I actually get the context data that are declared in a BaseMixin's get_context_data() and use it in a View that doesn't have override get_context_data()?
Example:
class BaseMixin(object):
def get_context_data(self, *args, **kwargs):
context = super(BaseMixin, self).get_context_data(**kwargs)
context['test'] = 1
return context
And the view that extends this BaseMixin:
class FooView(BaseMixin, View):
def foo(self, request):
context = super(BaseMixin, self).get_context_data(**kwargs)
# do something
return
This is not working actually, even after put **kwargs as a parameter in foo(). The error is 'super' object has no attribute 'get_context_data'.
So is there a way to get context data which was set in BaseMixin in FooView ?
Thanks for your answers :)
Thanks to #Sayes and all answer posters, I finally solved this problem.
From what I figured out, the problem is actually in BaseMixin, the inherited class of BaseMixin, which is object, doesn't have a get_context_data() function, just like #Sayes commented.
After replace this object with ContextMixin, everything works perfectly, at least perfectly for now.
Here is the modified BaseMixin:
class BaseMixin(ContextMixin):
def get_context_data(self, *args, **kwargs):
# do something
return context