Django: Accessing URL variables in Class Based Views and Forms

问题

I'm trying to create an object in Django using the standard class based views and form libraries. Three fields in my form are dependent upon a domain variable captured from the URL pattern. My questions are:

How do I access domain within CreateSubscription so that I can set Subscription.site to Site.objects.filter(domain=domain)[0]?
How do I limit the dropdown fields rendered from CreateSubscriptionForm so that plan displays only SubscriptionPlan.objects.filter(site=Site.objects.filter(domain=domain)[0]) and payment_profile is limited to PaymentProfile.objects.filter(user=request.user)?

For clarity's sake, the domain in r'^subscribe/(?P<domain>\w+\.\w+)/$' is unrelated to my own site's domain. The django.contrib.sites framework won't help me here.

Thanks in advance for helping me untangle all of these CBV methods. :)

The URL pattern is:

from django.conf.urls import patterns, url
from accounts.views import *

url(r'^subscribe/(?P<domain>\w+\.\w+)/$', 
    CreateSubscription.as_view(), name='subscribe_to_site'),
)

The view in question is:

from accounts.forms import *
from accounts.models import *

class CreateSubscription(CreateView):
    model = Subscription
    form_class = CreateSubscriptionForm

    def form_valid(self, form):
        form.instance.user = self.request.user
        return super(CreateSubscription, self).form_valid(form)

The relevant models are:

from django.conf import settings
from django.contrib.sites.models import Site
from django.db import models

class PaymentProfile(models.Model):
    user = models.ForeignKey(settings.AUTH_USER_MODEL)

class SubscriptionPlan(models.Model):
    site = models.ForeignKey(Site)
    name = models.CharField(max_length=40)

class Subscription(models.Model):
    user = models.ForeignKey(settings.AUTH_USER_MODEL)
    site = models.ForeignKey(Site)
    plan = models.ForeignKey(SubscriptionPlan)
    payment_profile = models.ForeignKey(PaymentProfile)

And, finally, my form is:

from accounts.models import *

class CreateSubscriptionForm(forms.ModelForm):
    class Meta:
        model = Subscription
        exclude = ('user', 'site', )

回答1:

To access the data passed to the view, use self.args and self.kwargs

from accounts.forms import *
from accounts.models import *

class CreateSubscription(CreateView):
    model = Subscription
    form_class = CreateSubscriptionForm

    def form_valid(self, form):
        form.instance.user = self.request.user
        form.instance.site = Site.objects.get(domain=self.kwargs['domain'])
        return super(CreateSubscription, self).form_valid(form)

To restrict the dropdown content, you need to set the queryset for those fields. Very basically, something along these lines:

class CreateSubscriptionForm(forms.ModelForm):
    plan = forms.ModelChoiceField(
        queryset=SubscriptionPlan.objects.filter(xxx)
    )

    ...

    class Meta:
        model = Subscription
        exclude = ('user', 'site', )

This can also be done inside the view so that you have access to the domain.

class CreateSubscription(CreateView):
    model = Subscription
    form_class = CreateSubscriptionForm

    def get_form(self, form_class):
        """
        Returns an instance of the form to be used in this view.
        """
        form = super(CreateSubscription, self).get_form(form_class)
        form.fields['plan'].queryset = SubscriptionPlan.objects.filter(site__domain=self.kwargs['domain'])
        return form

    ...

    def form_valid(self, form):
        form.instance.user = self.request.user
        form.instance.site = Site.objects.get(domain=self.kwargs['domain'])
        return super(CreateSubscription, self).form_valid(form)

来源：https://stackoverflow.com/questions/15511941/django-accessing-url-variables-in-class-based-views-and-forms

标签

django

django-views