表单中的 Django 通用视图初始值答案

【问题标题】：Django generic view initial value in form表单中的 Django 通用视图初始值
【发布时间】：2020-07-14 17:08:28
【问题描述】：

我想在我的表单中有默认值，这应该是当前用户的选择。例如，用户选择为一部电影提供 5，他应该在表单中看到 5，直到他更改它。

views.py

class MovieDetailView(FormMixin, DetailView):
    model = Movie
    template_name = 'main/detail_movie.html'
    context_object_name = 'movie'
    form_class = RateForm

    def get_context_data(self, **kwargs):
        context = super(MovieDetailView, self).get_context_data(**kwargs)
        context['form'] = RateForm(initial={'movie': self.object})
        context['my_rate'] = Rate.objects.filter(
                sender=self.request.user,
                movie=self.get_object()).first()
        return context

    def post(self, request, *args, **kwargs):
        self.object = self.get_object()
        form = self.get_form()
        if request.method == 'POST':
            if form.is_valid():
                new_rate, _ = Rate.objects.update_or_create(
                sender=self.request.user, 
                movie=self.object,
                defaults={'choice': form.cleaned_data['choice']}
            )
                return JsonResponse({'rate': model_to_dict(new_rate)}, status=200)
        else:
            return self.form_invalid(form)

    def get_success_url(self):
        return reverse('detail_movie', kwargs={'slug': self.object.slug})

我正在尝试 get_initial 方法，但它仍然默认为我提供“---”形式。

def get_initial(self):
        return {'choice': Rate.objects.filter(movie=self.object, sender=self.request.user).first().choice }

即使这样也行不通

def get_initial(self):
        return {'choice': 1 }

【问题讨论】：

标签： python django forms

【解决方案1】：

把它放在你的表单中。

form = RateForm(initial={'choice': 1})

【讨论】：

我像这个 form = self.get_form() 一样初始化它，我不能按照你的方式这样做......

【解决方案2】：

如果你想使用FormMixin和get_initial方法你需要在get_context_data中使用get_form方法

class MovieDetailView(FormMixin, DetailView):
    model = Movie
    template_name = 'main/detail_movie.html'
    context_object_name = 'movie'
    form_class = RateForm

    def get_initial(self):
        initial = super(MovieDetailView, self).get_initial()
        initial['movie'] = self.object # selected movie
        rate = Rate.objects.filter( # attempt to get rate
            movie=self.object,
            sender=self.request.user
        ).first()
        if rate is not None: # set rate choice only if it has been done before
            initial['choice'] = rate.choice
        return initial

    def get_context_data(self, **kwargs):
        context = super(MovieDetailView, self).get_context_data(**kwargs)
        context['form'] = self.get_form() # use from mixin instead manual init
        return context

    def post(self, request, *args, **kwargs):
        self.object = self.get_object()
        form = self.get_form()
        if request.method == 'POST':
            if form.is_valid():
                new_rate, _ = Rate.objects.update_or_create(
                sender=self.request.user, 
                movie=self.object,
                defaults={'choice': form.cleaned_data['choice']}
            )
                return JsonResponse({'rate': model_to_dict(new_rate)}, status=200)
        else:
            return self.form_invalid(form)

    def get_success_url(self):
        return reverse('detail_movie', kwargs={'slug': self.object.slug})

【讨论】：

谢谢，这是我找到解决方案的好建议。

【解决方案3】：

好的，我只需要输入 'choice': Rate.objects.filter(movie=self.object, sender=self.request.user).first().choice 到我的context['form'] 那里我已经有了首字母：

def get_context_data(self, **kwargs):
        context = super(MovieDetailView, self).get_context_data(**kwargs)
        context['form'] = RateForm(
        initial={
        'movie': self.object,
        'choice': Rate.objects.filter(movie=self.object, sender=self.request.user).first().choice
        })
        context['my_rate'] = Rate.objects.filter(
                sender=self.request.user,
                movie=self.get_object()).first()
        return context

【讨论】：