I have a scenario where I am trying to send different messages to the user in the event that they are not authorized to see a record or if the record does not exist. I have been able to get the interface to send a message to the user if a 404 occurs, but can't quite figure out the logic based on criteria of the record. I've been playing with get, get_object, or get_object_or_404 and nothing quite works.
Here is my DetailView..
class BookSearchDetailView(LoginRequiredMixin,DetailView):
model = Book
context_object_name = 'book_detail'
template_name = 'book/book_search_detail.html'
def get_object(self, queryset=None):
return get_object_or_404(Book, book_number=self.request.GET.get("q"))
def get(self, request, *args, **kwargs):
book_number=self.request.GET.get("q")
try:
self.object = self.get_object()
except Http404:
messages.add_message(self.request, messages.INFO, 'Book Number %s Not Found' % book_number )
return HttpResponseRedirect(reverse('Book:book_number_search'))
context = self.get_context_data(object=self.object)
return self.render_to_response(context)
except Not a Preference:
Book_number exists but is not self.request.user.preferences.all()
I realize the except Not a Preference doesn't work, but I am illustrating what I am trying to do.
Here is my model.
class Book(models.Model):
book_name = models.CharField(max_length=80,null=True,unique=False)
book_number = models.IntegerField(editable=True,null=True)
Note I do not have a slug defined to my model. In the current code above, this doesn't cause any problems. When I have played with different code variations, one of the error messages I get is that DetailView must be called with a pk or a slug.
I am ultimately trying to filter the book so that if the user doesn't have attributes to allow them to see the book it would essentially return none.
I have also tried to override get_queryset, but when I use the code below,
def get_queryset(self):
queryset = super(BookSearchDetailView, self).get_queryset()
return queryset.filter(book_number__in=self.request.user.preferences.all())
However, when I define the code above, my DetailView does not seem to honor it or have any effect.
What I've read is that the get_object either gets the object or 404. I've got that piece work working fine. Just can't figure out how to incorporate a third variation of error message.
Thanks in advance for any thoughts.
Related
I am trying to make a simple form, that conditionally shows the website input field based on the value of another database field (that is not on the form) status. For the sake of this process the status field is not editable by the user, just by the admin. Both fields are in the same table: profile.
After working at this for a while I copped-out and just did the conditional hiding and showing on the template. But, I realise this is the unsophisticated method, and would like to improve it.
What I tried so far in forms.py:
class WebsiteForm(forms.ModelForm):
class Meta:
model = Profile
fields = (
'e-mail',
'website',
)
if Profile.status == 'personal' :
exclude = ('website',)
This method in forms.py works effectively, in that I can conditionally show and hide the field if I use test comparitors in the if statement like:
if 1 == 1:
or
if 1 != 1:
But, I cannot get an effective test using the field Profile.status, the value in the field seems to be unavailable at the point the if test in forms.py is performed.
If I use print(Profile.status) I get the following output in the terminal: user__profile__status__isnull, so I think this means that I am at least testing the correct field in the database. Although I am also noting that this output only shows at initialisation of runserver, not when the form page is accessed.
One final point, the user is authenticated and editing their own record.
Any help very much appreciated.
After a lot of trial and even more error, and some wide-ranging searching, I found the answer via the documentation at https://ccbv.co.uk/.
Essentially the path I decided to take was to use a different form for the respective fields that I wanted to use (I'm sure there are other solutions out there that add or subtract fields from the views). This involved changing the form_class with get_form_class:
# views.py
class telephone_view(UpdateView):
template_name = 'account/telephone.html'
#no need to define "form_class" here
#form_class = TelephoneForm
success_url = '/accounts/telephone/'
def get_form_class(self):
if self.request.user.profile.status == 'managed':
messages.success(self.request, _('you got the managed form'))
return TelephoneFormExtended
else:
messages.success(self.request, _('you got the other form'))
return TelephoneFormLight
def get_object(self, queryset=None):
return Profile.get_or_create_for_user(self.request.user)
def form_valid(self, form):
messages.success(self.request, _('Your telephone setting was updated'))
return super(telephone_view, self).form_valid(form)
#method_decorator(login_required)
def dispatch(self, *args, **kwargs):
return super(telephone_view, self).dispatch(*args, **kwargs)
After working it out for myself I also found this answer which does the same thing:
Updateview with dynamic form_class
I've been working with Django for about 3 months now and feel I'm getting a bit better, working my way up to class based views. On the surface they seem cleaner and easier to understand and in some cases they are. In others, not so much. I am trying to use a simple drop down view via ModelChoiceField and a form. I can get it to work with a function based view as shown below in my views.py file:
def book_by_name(request):
form = BookByName(request.POST or None)
if request.method == 'POST':
if form.is_valid():
book_byname = form.cleaned_data['dropdown']
return HttpResponseRedirect(book_byname.get_absolute_url1())
return render(request,'library/book_list.html',{'form':form})
Here is my form in forms.py:
class BookByName(forms.Form):
dropdown = forms.ModelChoiceField(queryset=Book.objects.none())
def __init__(self, *args, **kwargs):
super(BookByName, self).__init__(*args, **kwargs)
self.fields['dropdown'].widget.attrs['class'] = 'choices1'
self.fields['dropdown'].empty_label = ''
self.fields['dropdown'].queryset = Book.objects.order_by('publisher')
This code works. When I have tried to convert to a Class Based View, that's when the trouble begins. I tried to do something like this in views.py:
class BookByNameView(FormView, View):
form_class = BookByName
initial = { 'Book' : Book }
template_name = 'library/book_list.html'
def get(self, request, *args, **kwargs):
form = self.form_class(initial=self.initial)
return render(request, self.template_name, {'form': form})
def get_success_url(self, *args):
return reverse_lazy('library:book_detail', args = (self.object.id,))
When using this with the same form, I receive an attribute error,
'BookByNameView' object has no attribute 'object'.
I've tried ListView as well and received several other errors along the way. The get_success_url also needs to take in a primary key and I can't figure out how to get that passed in as well. Again, I'm a 3 month Django newbie so please be gentle and thanks in advance for your thoughts and suggestions! I feel like I'm in the ballpark...just can't find my seat! I'm very open to doing this differently, if there's a cleaner/better way to do this!
Based on the latest feedback, it would appear the Class Based View should look like:
class BookNameView(FormView):
form_class = BookName
template_name = 'library/book_list.html'
def get_success_url(self, *args):
return reverse_lazy('library:book_detail')
Is this correct? I ran a test version of this and in response to your question as to why I am using self.object.id at all, I am trying to get the pk from the modelchoicefield that I am using to return the view I am trying to get. This may be where I am getting a bit lost. I am trying to get the detail view from the modelchoicefield dropdown, and return the book that is selected. However, I can't seem to pass the pk to this view successfully.
I updated my code to...
class BookByNameView(FormView, ListView):
model = Book
form_class = BookByName
template_name = 'library/book_list.html'
def get_success_url(self, *args):
return reverse_lazy('library:book_detail')
But now it says error...Reverse for 'book_detail' with no arguments not found.
Why are you using self.object there at all? You used form.cleaned_data in the original view, that's what you should use in the class based version too. Note that the form is passed to form_valid.
Note that you've done lots of other weird things too. Your getmethod is pointless, as is your definition of the initial dict; you should delete them both. Also, FormView already inherits from View, there's no need to have View in your declaration explicitly.
You can override the form_valid() function in FormView to achieve what you want. If the form is valid then it is passed to the form_valid() function.
Try this:
class BookByNameView(FormView):
model = Book
form_class = BookByName
template_name = 'library/book_list.html'
def form_valid(self, form):
bookbyname = form.cleaned_data['dropdown']
return HttpResponseRedirect(bookbyname.get_absolute_url())
I'm new to python and trying to understand how to get a dynamic ModelChoiceField to work. It works fine when I select an object with all but I'm trying to get the dropdown to reflect a user's attribute. Here is my code:
Forms.py
class ViewByMake(forms.Form):
dropdown = forms.ModelChoiceField(queryset=Make.objects.none())
def __init__(self, user, *args, **kwargs):
user = kwargs.pop('user')
super(ViewByMake, self).__init__(*args, **kwargs)
qs = Make.objects.filter(user=user)
self.fields['dropdown'].queryset = qs
self.fields['dropdown'].widget.attrs['class'] = 'choices1'
self.fields['dropdown'].empty_label = ''
Views.py
def view_bymake(request):
form = ViewByMake(request.POST or None, user=request.user)
if request.method == 'POST':
if form.is_valid():
make = form.cleaned_data['dropdown']
return HttpResponseRedirect(make.get_absolute_url1())
return render(request,'make/view_make.html',{'form':form})
This code works fine if I remove all user= references but then only returns the full make objects list which is not what I want. I found a very similar question on StackOverflow, but when I duplicated the code identically, it still doesn't work and it is giving me the following error:
init() got multiple values for argument 'user'
I searched the end of the internet on this topic. I'm open to other ideas if I'm approaching this poorly. I'm trying to basically get a filtered list based on criteria associated with a user's profile. I definitely need the drop down field to be specific to a user based on a profile setting. Thanks for your help in advance. I'm running django 1.11.2 and Python 3.6.1.
This is the updated model which need to include the user attribute which I didn't realize that I had to specify:
class Make(models.Model):
name = models.CharField(max_length=264,unique=True)
user = models.ForeignKey(User,null=True,on_delete=models.CASCADE)
Try with request, send request from form and get request in init method of form
views.py
def view_bymake(request):
form = ViewByMake(request.POST or None, request=request)
forms.py
def __init__(self, user, *args, **kwargs):
self.request = kwargs.pop('request', None)
super(ViewByMake, self).__init__(*args, **kwargs)
qs = Make.objects.filter(user=self.request.user)
self.fields['dropdown'].queryset = qs
self.fields['dropdown'].widget.attrs['class'] = 'choices1'
self.fields['dropdown'].empty_label = ''
The answer to my original question, how do I get user=user to work consists of making sure that your form, view, and model all reference user. I originally had the user reference in the view and the form correct, but I neglected to make sure user= was specified on the model I was referencing. I thought it was built in, but turns out you have to specifically reference it on your model. I'm new at this so it was a learning experience. On to the next challenge!
After resolving some of my troubles while converting from django-rest-framwork 0.3.2 to the lates 2.1.9 I cannot see to fix this one (which i agree with a blog of Reinout.... it's a real pain in the ...)
I had this code:
class ApiSomeInputView(View):
form = ApiSomeForm
permissions = (IsAuthenticated, )
resource=SomeResource
def get(self, request):
"""
Handle GET requests.
"""
return "Error: No GET request Possible, use post"
def post(self, request, format=None):
some_thing = self.CONTENT['some_thing']
# check if something exist:
something = get_object_or_none(Something,some_field=int(some_thing))
if not something:
raise _404_SOMETHING_NOT_FOUND
#Note exludes are set in SomeResource
data = Serializer(depth=4).serialize(something)
return Response(status.HTTP_200_OK, data)
Now I have followed the tutorial and saw how you can do this different (maybe even prettier). By using slug in the url.
However.... I want to keep things backward compatible for the client side software... so I want to have this without putting the value of the query in the url. The client side uses json data and ContentType json in the header of a post.
In the first version of django rest framwork, I even got a nice browsable form in which to fill in the values for this query
My question: how to get this done in the latest version?
I can't seem to get a form in the views.... where I can fill in values and use in the proces
maybe good to post what I have tried until sofar...
first I changed the ModelResource in a Serializer:
class SomethingSerializer(HyperlinkedModelSerializer):
class Meta:
model = Something
#exclude = ('id',)
depth = 4
and than the view changed in to:
class ApiSomeInputView(APIView):
permissions = (IsAuthenticated, )
def post(self, request, format=None):
some_thing = request.DATA['some_thing']
# check if something exist: .... well actually this above already does not work
something = get_object_or_none(Something,some_field=int(some_thing))
if not something:
raise _404_SOMETHING_NOT_FOUND
serializer = SomethingSerializer(something)
return Response(status.HTTP_200_OK, serializer.data)
Note: Bases upon the accepted answer (by Tom Christie) I als put an answer in which I show how I got it working (in more detail).
When you're inheriting from APIView, the browseable API renderer has no way of knowing what serializer you want to use to present in the HTML, so it falls back to allowing you to post a plain JSON (or whatever) representation.
If you instead inherit from GenericAPIView, set the serializer using the serializer_class attribute, and get an instance of the serializer using the get_serializer(...) method - see here, then the browseable API will use a form to display the user input.
Based upon the answer of Tom Christie (which I'll accept as the answer). I got it working:
I made an extra serializer which defines the field(s) to be shown to fill in for the post and shown using the GenericAPIView... (correct me if I Am wrong Tom, just documenting it here for others... so better say it correct)
class SomethingSerializerForm(Serializer):
some_thing = serializers.IntegerField()
And with this serializer and the other one I aready had.
And a view:
class ApiSomeInputView(GenericAPIView):
permissions = (IsAuthenticated, )
model = Something
serializer_class = SomethingSerializerForm
def post(self, request, *args, **kwargs):
serializer = self.get_serializer(data=request.DATA)
if not serializer.is_valid():
raise ParseError(detail="No valid values")
some_thing = request.DATA['some_thing']
something = get_object_or_none(Something,some_field=int(some_thing))
if not something:
raise Http404
serializer = SomethingSerializer(something)
return Response(serializer.data)
Above is working, and exactly the same as before....
I still got the feeling I Am abusing the Serializer class as a Form.
I'd like to write an except clause that redirects the user if there isn't something in a queryset. Any suggestions welcome. I'm a Python noob, which I get is the issue here.
Here is my current code:
def get_queryset(self):
try:
var = Model.objects.filter(user=self.request.user, done=False)
except:
pass
return var
I want to do something like this:
def get_queryset(self):
try:
var = Model.objects.filter(user=self.request.user, done=False)
except:
redirect('add_view')
return var
A try except block in the get_queryset method isn't really appropriate. Firstly, Model.objects.filter() won't raise an exception if the queryset is empty - it just returns an empty queryset. Secondly, the get_queryset method is meant to return a queryset, not an HttpResponse, so if you try to redirect inside that method, you'll run into problems.
I think you might find it easier to write a function based view. A first attempt might look like this:
from django.shortcuts import render
def my_view(request):
"""
Display all the objects belonging to the user
that are not done, or redirect if there are not any,
"""
objects = Model.objects.filter(user=self.request.user, done=False)
if not objects:
return HttpResponseRedirect("/empty-queryset-url/")
return render(request, 'myapp/template.html', {"objects": objects})
The advantage is that the flow of your function is pretty straight forward. This doesn't have as many features as the ListView generic class based view (it's missing pagination for example), but it is pretty clear to anyone reading your code what the view is doing.
If you really want to use the class based view, you have to dig into the CBV documentation for multiple object mixins and the source code, and find a suitable method to override.
In this case, you'll find that the ListView behaviour is quite different to what you want, because it never redirects. It displays an empty page by default, or a 404 page if you set allow_empty = False. I think you would have to override the get method to look something like this (untested).
class MyView(ListView):
def get_queryset(self):
return Model.objects.filter(user=self.request.user, done=False)
def get(self, request, *args, **kwargs):
self.object_list = self.get_queryset()
if len(self.object_list == 0):
return HttpResponseRedirect("/empty-queryset-url/")
context = self.get_context_data(object_list=self.object_list)
return self.render_to_response(context)
This is purely supplemental to #Alasdair's answer. It should really be a comment, but couldn't be formatted properly that way. Instead of actually redefining get on the ListView, you could override simply with:
class MyView(ListView):
allow_empty = False # Causes 404 to be raised if queryset is empty
def get(self, request, *args, **kwargs):
try:
return super(MyView, self).get(request, *args, **kwargs)
except Http404:
return HttpResponseRedirect("/empty-queryset-url/")
That way, you're not responsible for the entire implementation of get. If Django changes it in the future, you're still good to go.