坚持Django FormView数据

Question

I have a FormView that generates a review of an object (which it is generically related to) and then links it to the object and saves it when the form is completed.

The issue I'm having is that I have no way to hold onto the data of the object I want to connect to. This means that I need to 'look it up' for context (template rendering) for valid processing (to do the linking) and for the success (to generate an appropriately reversed url.

Is there a better way to be binding the review to the object? Or better yet, is there a way to persist form data that I'm missing?

EDIT: Sorry the login decorator was on dispatch. I removed that method because SO was complaining about too much code and I didn't think it was relevant... I must have missed the decoratot

class ReviewCreate(FormView):
    template_name = 'food/item_add_review.html'
    form_class = ReviewForm
    review_item = None


    def get_context_data(self, **kwargs):
        context = super(ReviewCreate, self).get_context_data(**kwargs)

        item_modelname = self.kwargs.get('model')
        item_model = apps.get_model('food',item_modelname)
        review_item = get_object_or_404(item_model,pk=self.kwargs.get('pk'))

        context['item'] = review_item

        return context

    def form_valid(self, form):
        item_modelname = self.kwargs.get('model')
        item_model = apps.get_model('food',item_modelname)
        review_item = get_object_or_404(item_model,pk=self.kwargs.get('pk'))

        r = form.save(commit=False)

        r.content_object=review_item
        r.save()

        return super(ReviewCreate, self).form_valid(form)

    def get_success_url(self): 
        item_modelname = self.kwargs.get('model')
        item_model = apps.get_model('food',item_modelname)
        review_item = get_object_or_404(item_model,pk=self.kwargs.get('pk'))

        return reverse( 'pkitem', kwargs = {'pk': review_item.id, 'model':item_modelname},)

Answer 1

The view is an object right, so you just assign your values to instance variables, ie "to self" ( this is thread-safe ). Like this:

class ReviewCreate(FormView):
    template_name = 'food/item_add_review.html'
    form_class = ReviewForm

    @method_decorator(login_required)  # Use a class level mixin instead
    def get_context_data(self, **kwargs):
        return super(
            ReviewCreate, 
            self
        ).get_context_data(
            item=self.review_item,
            **kwargs
        )

    def lookup_review_item(self):
        self.item_modelname = self.kwargs.get('model')
        item_model = apps.get_model('food', self.item_modelname)
        self.review_item = get_object_or_404(
            item_model, 
            pk=self.kwargs.get('pk')
        )

    def dispatch(self, request, *args, **kwargs):
        # lookup performed here to be set for both GET and POST
        self.lookup_review_item()
        return super(ReviewCreate, self).dispatch(request, *args, **kwargs)

    def form_valid(self, form):
        r = form.save(commit=False)
        r.content_object=self.review_item
        r.save()
        return super(ReviewCreate, self).form_valid(form)

    def get_success_url(self):
        return reverse(
            'pkitem', 
            kwargs = {
                'pk': self.review_item.id, 
                'model': self.item_modelname
            },
        )

Answer 2

The default form_valid() method for FormView redirects to the success url and reinitializes the form. You can make the form data persist by overriding form_valid() :

def form_valid(self, form):
    return super(YourFormView, self).get(form)

This will redirect to your success url with a (bounded) form having the posted data. The form is added to the context so you can use the data in your template or in your view as you wish.

(Django version 1.11.7)

Answer 3

The get_context_data should always return the context dictionary. It doesn't make sense to use the login_required decorator with it, because that means it might return a redirect response instead.

It would be better decorate the dispatch method instead. In your dispatch , you can set attributes on the instance.

class ReviewCreate(FormView):

    @method_decorator(login_required)
    def dispatch(self, request, *args, **kwargs):
        self.item_modelname = self.kwargs.get('model')
        self.item_model = apps.get_model('food',item_modelname)
        self.review_item = get_object_or_404(item_model,pk=self.kwargs.get('pk'))
        return super(ReviewCreate, self).dispatch(request, *args, **kwargs)

Then, in your other methods, you can access the attributes, for example:

    def get_context_data(self, **kwargs):
        context = super(ReviewCreate, self).get_context_data(**kwargs)
        context['item'] = self.review_item
        return context