django1/django/views/generic/edit.py

307 lines
9.5 KiB
Python

import inspect
import warnings
from django.core.exceptions import ImproperlyConfigured
from django.forms import models as model_forms
from django.http import HttpResponseRedirect
from django.utils import six
from django.utils.deprecation import RemovedInDjango20Warning
from django.utils.encoding import force_text
from django.views.generic.base import TemplateResponseMixin, ContextMixin, View
from django.views.generic.detail import (SingleObjectMixin,
SingleObjectTemplateResponseMixin, BaseDetailView)
class FormMixinBase(type):
def __new__(cls, name, bases, attrs):
get_form = attrs.get('get_form')
if get_form and inspect.isfunction(get_form):
try:
inspect.getcallargs(get_form, None)
except TypeError:
warnings.warn(
"`%s.%s.get_form` method must define a default value for "
"its `form_class` argument." % (attrs['__module__'], name),
RemovedInDjango20Warning, stacklevel=2
)
def get_form_with_form_class(self, form_class=None):
if form_class is None:
form_class = self.get_form_class()
return get_form(self, form_class=form_class)
attrs['get_form'] = get_form_with_form_class
return super(FormMixinBase, cls).__new__(cls, name, bases, attrs)
class FormMixin(six.with_metaclass(FormMixinBase, ContextMixin)):
"""
A mixin that provides a way to show and handle a form in a request.
"""
initial = {}
form_class = None
success_url = None
prefix = None
def get_initial(self):
"""
Returns the initial data to use for forms on this view.
"""
return self.initial.copy()
def get_prefix(self):
"""
Returns the prefix to use for forms on this view
"""
return self.prefix
def get_form_class(self):
"""
Returns the form class to use in this view
"""
return self.form_class
def get_form(self, form_class=None):
"""
Returns an instance of the form to be used in this view.
"""
if form_class is None:
form_class = self.get_form_class()
return form_class(**self.get_form_kwargs())
def get_form_kwargs(self):
"""
Returns the keyword arguments for instantiating the form.
"""
kwargs = {
'initial': self.get_initial(),
'prefix': self.get_prefix(),
}
if self.request.method in ('POST', 'PUT'):
kwargs.update({
'data': self.request.POST,
'files': self.request.FILES,
})
return kwargs
def get_success_url(self):
"""
Returns the supplied success URL.
"""
if self.success_url:
# Forcing possible reverse_lazy evaluation
url = force_text(self.success_url)
else:
raise ImproperlyConfigured(
"No URL to redirect to. Provide a success_url.")
return url
def form_valid(self, form):
"""
If the form is valid, redirect to the supplied URL.
"""
return HttpResponseRedirect(self.get_success_url())
def form_invalid(self, form):
"""
If the form is invalid, re-render the context data with the
data-filled form and errors.
"""
return self.render_to_response(self.get_context_data(form=form))
class ModelFormMixin(FormMixin, SingleObjectMixin):
"""
A mixin that provides a way to show and handle a modelform in a request.
"""
fields = None
def get_form_class(self):
"""
Returns the form class to use in this view.
"""
if self.form_class:
return self.form_class
else:
if self.model is not None:
# If a model has been explicitly provided, use it
model = self.model
elif hasattr(self, 'object') and self.object is not None:
# If this view is operating on a single object, use
# the class of that object
model = self.object.__class__
else:
# Try to get a queryset and extract the model class
# from that
model = self.get_queryset().model
if self.fields is None:
raise ImproperlyConfigured(
"Using ModelFormMixin (base class of %s) without "
"the 'fields' attribute is prohibited." % self.__class__.__name__
)
return model_forms.modelform_factory(model, fields=self.fields)
def get_form_kwargs(self):
"""
Returns the keyword arguments for instantiating the form.
"""
kwargs = super(ModelFormMixin, self).get_form_kwargs()
if hasattr(self, 'object'):
kwargs.update({'instance': self.object})
return kwargs
def get_success_url(self):
"""
Returns the supplied URL.
"""
if self.success_url:
url = self.success_url % self.object.__dict__
else:
try:
url = self.object.get_absolute_url()
except AttributeError:
raise ImproperlyConfigured(
"No URL to redirect to. Either provide a url or define"
" a get_absolute_url method on the Model.")
return url
def form_valid(self, form):
"""
If the form is valid, save the associated model.
"""
self.object = form.save()
return super(ModelFormMixin, self).form_valid(form)
class ProcessFormView(View):
"""
A mixin that renders a form on GET and processes it on POST.
"""
def get(self, request, *args, **kwargs):
"""
Handles GET requests and instantiates a blank version of the form.
"""
form = self.get_form()
return self.render_to_response(self.get_context_data(form=form))
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()
if form.is_valid():
return self.form_valid(form)
else:
return self.form_invalid(form)
# PUT is a valid HTTP verb for creating (with a known URL) or editing an
# object, note that browsers only support POST for now.
def put(self, *args, **kwargs):
return self.post(*args, **kwargs)
class BaseFormView(FormMixin, ProcessFormView):
"""
A base view for displaying a form
"""
class FormView(TemplateResponseMixin, BaseFormView):
"""
A view for displaying a form, and rendering a template response.
"""
class BaseCreateView(ModelFormMixin, ProcessFormView):
"""
Base view for creating an new object instance.
Using this base class requires subclassing to provide a response mixin.
"""
def get(self, request, *args, **kwargs):
self.object = None
return super(BaseCreateView, self).get(request, *args, **kwargs)
def post(self, request, *args, **kwargs):
self.object = None
return super(BaseCreateView, self).post(request, *args, **kwargs)
class CreateView(SingleObjectTemplateResponseMixin, BaseCreateView):
"""
View for creating a new object instance,
with a response rendered by template.
"""
template_name_suffix = '_form'
class BaseUpdateView(ModelFormMixin, ProcessFormView):
"""
Base view for updating an existing object.
Using this base class requires subclassing to provide a response mixin.
"""
def get(self, request, *args, **kwargs):
self.object = self.get_object()
return super(BaseUpdateView, self).get(request, *args, **kwargs)
def post(self, request, *args, **kwargs):
self.object = self.get_object()
return super(BaseUpdateView, self).post(request, *args, **kwargs)
class UpdateView(SingleObjectTemplateResponseMixin, BaseUpdateView):
"""
View for updating an object,
with a response rendered by template.
"""
template_name_suffix = '_form'
class DeletionMixin(object):
"""
A mixin providing the ability to delete objects
"""
success_url = None
def delete(self, request, *args, **kwargs):
"""
Calls the delete() method on the fetched object and then
redirects to the success URL.
"""
self.object = self.get_object()
success_url = self.get_success_url()
self.object.delete()
return HttpResponseRedirect(success_url)
# Add support for browsers which only accept GET and POST for now.
def post(self, request, *args, **kwargs):
return self.delete(request, *args, **kwargs)
def get_success_url(self):
if self.success_url:
return self.success_url % self.object.__dict__
else:
raise ImproperlyConfigured(
"No URL to redirect to. Provide a success_url.")
class BaseDeleteView(DeletionMixin, BaseDetailView):
"""
Base view for deleting an object.
Using this base class requires subclassing to provide a response mixin.
"""
class DeleteView(SingleObjectTemplateResponseMixin, BaseDeleteView):
"""
View for deleting an object retrieved with `self.get_object()`,
with a response rendered by template.
"""
template_name_suffix = '_confirm_delete'