I have been able to successfully use the FormPreview in django 1.4 to preview before submitting for adding a new record in the Event model. Love the functionality.
Here is how I do this:
#urls.py
url(r'^addevent/', EventFormPreview(EventForm)),
#views.py
class EventFormPreview(FormPreview):
def done(self, request, cleaned_data):
pdb.set_trace()
new_event = Event(**cleaned_data)
new_event.user = request.user
new_event.save()
return render_to_response("event/thanks.html",
{'cleandata': cleaned_data,},
context_instance=RequestContext(request),
)
Now, I want to have a similar editevent() in my view that goes through the same preview process and the final submit. The only difference will be that the form will be pre-populated with the data I am I trying to edit. How do I do this by writing minimal code and making use of the existing preview flow? Here is what I think the urls.py portion will look like:
url(r'^(?i)editevent/(?P<id>\d+)/$', EditEventFormPreview(EventForm)),
I suspect I will have to redefine the init() in the EventFormPreview() and load the data there. Please let me know how to do this..
For once I am glad no one responded to my question - forced me to learn about oop.
So here is how I got what I wanted, and I think it is good pythonic way of doing it.
I override the parse_params() to get the record id, and then override the get_initial() to populate the form with the data. Then in the done(), I bring up the old record, and update it with the cleaned_data.
class EditEventFormPreview(FormPreview):
def parse_params(self, *args, **kwargs):
self.state["recordid"] = kwargs["id"]
pass
def get_initial(self, request):
ob = Event.objects.filter(pk=self.state["recordid"]).values()[0]
return ob
def done(self, request, cleaned_data):
new_event = Event.objects.get(pk=self.state["recordid"])
for (key, value) in cleaned_data.items():
setattr(new_event, key, value)
new_event.user = request.user
new_event.save()
return render_to_response("event/thanks.html",
{'cleandata': cleaned_data,},
context_instance=RequestContext(request),
)
Related
I am trying to manually change a foreign key field (Supplier) of a model (Expenditure). I override the UpdateView post method of Expenditure and handle forms for other models in this method too. A new SupplierForm is also rendered in this view and I am tracking if this form is changed via has_changed() method of the form. If this form has changed, what I ask is overriding the related_supplier field of ExpenditureForm and picking newly created Supplier by this statement:
if supplier_form_changed:
new_supplier = related_supplier_form.save(commit=False)
new_supplier.save()
....
# This statement seems to have no effect
self.object.related_supplier = new_supplier
I override the post method with super(), so even though I explicitly state save() method for all related forms, however I don't call the save method of main model (Expenditure) since it is already handled after super(). This is what start and end of my method looks like;
def post(self, request, *args, **kwargs):
context = request.POST
related_receipt_form = self.receipt_form_class(context, request.FILES)
related_supplier_form = self.supplier_form_class(context, request.FILES)
self.object = self.get_object()
related_receipt = self.object.receipt
related_supplier_form = self.supplier_form_class(context)
expenditure_form = self.form_class(context)
inlines = self.construct_inlines()
....
return super().post(self, request, *args, **kwargs)
You may find the full code of my entire view here:
https://paste.ubuntu.com/p/ZtCfMHSBZN/
So my problem is self.object.related_supplier = new_supplier statement does not have any effect. After the update, old related_supplier object is still there, new one is saved but not attached to the updated Expenditure. Strange thing is I am doing a similar thing in the same view (also in CreateView) with receipt and no problem whatsoever.
I debugged the code via PyCharm, before the execution of super(), I can confirm that self.object.related_supplier is the newly created one, but when the super() executed, it returns back to the original supplier object.
you can override the form valid method to add things manually, an example shown below
def form_valid(self, form):
related_supplier_form.instance.related_supplier = new_supplier
valid_data = super(UpdateView, self).form_valid(form)
return valid_data
i'm new in Django and i'm learning about the views and the methods and how they work, especially with this problem. The thing is that I would like to know how to automatically save a value of a field in my model after updating an object in a UpdateView, for example when I update an object, in this case a report where I can assign a person to do it, I would like to save a model value that shows the "status" and save the value of "assigned" or something like that, to know if the report was already assigned or not. I know there are methods and that maybe one of them could be done by overwriting the class, but I do not know how to apply it or which one to use.
For help this is a simple class of a UpdateViews that i'm using:
class reporteupdate(UpdateView):
model = reporte_fallo
form_class = ReporteAsignar
template_name = 'formulario/jefe_asignar.html'
success_url = reverse_lazy('formulario:reporte_listar_jefe')
and the field of the model that I would like to assign a value to is called status.
i'm waiting for your help, since I'm stuck with that doubt. Thanks!!!
the query dict will be changable after you create a copy of it in post method so you can do this:-
class SomeUpdateView(UpdateView):
model=your model
form_class=you form
def post(self, request, **kwargs):
request.POST = request.POST.copy()
request.POST['status'] = 'Assigned'
return super(SomeUpdateView, self).post(request, **kwargs)
You could perhaps set the status flag after the form has been successfully validated, by overriding the form_valid() method in your reporteupdate view:
class reporteupdate(UpdateView):
...
def form_valid(self, form):
# Call super() to save the model and return the success url
resp = super().form_valid(form)
# Set your status flag
self.object.status = 'assigned'
self.object.save()
return resp
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 am using django update view for my model/records editing stuff like below
class EditProductView(LoginRequiredMixin, UpdateView):
model = Product
def get_template_names(self):
return ['website/product/edit_product.html']
def get_success_url(self):
return reverse('product_details', args=[self.kwargs['pk']])
def get_context_data(self, **kwargs):
publisher = Publisher.objects.get(product__id=self.kwargs['pk'])
context = super(EditProductView, self).get_context_data(**kwargs)
context.update(
{
'publisher':publisher,
}
)
return context
edit_product = EditProductView.as_view()
So what all i want/trying to do is alter(add some data, edit already submitted data according to website functionality) the POST data before submitting to form,
So i know that UpdateView has some method def def post(self, request, *args, **kwargs): , but i dont know exactly how to use it
Suppose below is the request.POST data i am getting
<QueryDict: {u'product_name': [u'Biscuit'], u'product_price': [u'1000'], u'product_tag': [u'']}>
So now i want to alter the above QueryDict and if the value of product_tag was empty i need assign some default one and submit with latest querdict
Also i know that Querydict is mutable, but because of sure i need to edit the POST data, before submitting/saving to database, i need to make that querydict as dict, then edit it, and convert back to querdict
So after all whats my question is
How can we alter the POST data in UpdateView before submitting/saving to database
Is the post method heplful?
The QueryDict is mutable after you create its .copy(). See the docs.
Update Example:
class SomeUpdateView(UpdateView):
def post(self, request, **kwargs):
request.POST = request.POST.copy()
request.POST['some_key'] = 'some_value'
return super(SomeUpdateView, self).post(request, **kwargs)
Here is much broader discussion about the topic.
Furthermore, shouldn't this be done in ModelForm subclass? You're certainly aware you can set custom form as a form_class in UpdateView. Such a logic usually needs unit tests and it's much easier to unit test logic which sits in the 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.