python - get_context_data 函数不返回 'form'

Question

我有以下表单的 Django 代码(django 版本 1.11):

class MyDocumentUpdateView(UpdateView):
    """ We extend UpdateView as we need to pass self.object in context as resource """
    model = MyDocument

    def get_context_data(self, **context):

        context[self.context_object_name] = self.object
        context['resource'] = self.object
        #context['form'] = self.get_form() <-- if I uncomment this it works
        return context

class DocumentUpdateView(MyDocumentUpdateView):
    form_class = MyDocumentForm
    def form_valid(self, form):
        doc = form.save(commit=False)
        doc.owner = self.request.user
        updateMyDocument(doc, form)
        return HttpResponseRedirect(
            reverse(
                'mydocs_detail',
                args=(
                    self.object.slug,
                )))

当我运行此代码时，出现错误:

'str' object has no attribute 'fields'

我意识到这个错误与context变量的返回有关。由于某种原因，上下文词典不包括“形式”。如图所示in the documentation :

get_context_data(**kwargs)¶
Calls get_form() and adds the result to the context data with the name ‘form’.

但在我的例子中，上下文字典不包含“表单”。

如果我使用 get_form() def，那么一切正常:

context['form'] = self.get_form()

但这对我来说似乎有点矫枉过正，我想更深入地了解为什么这不起作用。

然后我注意到在我的例子中我使用:

def get_context_data(self, **context):

而不是:

def get_context_data(self, **kwargs):

所以我将上下文定义如下:

context = super(DocumentUpdateView, self).get_context_data(**kwargs)

但是我收到以下错误:

maximum recursion depth exceeded

Answer 1

So I defined the context as following:

context = super(DocumentUpdateView, self).get_context_data(**kwargs)

您使用了错误的类，因为您在MyDocumentUpdateView处调用了它级别，应该是super(<b>MyDocumentUpdateView</b>, self).get_context_data(**kwargs) 。所以你应该将其实现为:

class MyDocumentUpdateView(UpdateView):
    """ We extend UpdateView as we need to pass self.object in context as resource """
    model = MyDocument

    def get_context_data(self, **kwargs):
        <b>context = super(MyDocumentUpdateView, self).get_context_data(**kwargs)</b>
        context['resource'] = self.object
        return context

话虽这么说，self.object已添加到上下文中，默认情况下作为模型的名称(因此此处为 mydocument ，您可以通过为 context_object_name 属性指定一个值来自行指定一个，例如:

class MyDocumentUpdateView(UpdateView):
    """ We extend UpdateView as we need to pass self.object in context as resource """
    model = MyDocument
    <b>context_object_name = 'resource'</b>

在这种情况下，上下文当然不再存储以其模型名称(或任何其他名称)下的对象。