人世一身霜雪, 归来仍是少年.

Django小技巧15: 使用基于类视图的Mixins

翻译整理自: simpleisbetterthancomplex.com

今天讲述三点关于 Mixins 使用的一些规范:

  • Django 提供的View 保持在继承的最右边.
  • Mixins 在基本视图的左侧
  • Mixins 应该继承Python的内置对象类型(object).

下面举例说明规则

Python
 
class FormMessageMixin(object):
    @property
    def form_valid_message(self):
        return NotImplemented

    form_invalid_message = 'Please correct the errors below.'

    def form_valid(self, form):
        messages.success(self.request, self.form_valid_message)
        return super(FormMessageMixin, self).form_valid(form)

    def form_invalid(self, form):
        messages.error(self.request, self.form_invalid_message)
        return super(FormMessageMixin, self).form_invalid(form)


class DocumentCreateView(FormMessageMixin, CreateView):
    model = Document
    fields = ('name', 'file')
    success_url = reverse_lazy('documents')
    form_valid_message = 'The document was successfully created!'

依类似的方式, 你可以在UpdateView中, 重用相同的FormMessageMixin, 并覆盖默认的form_invalid_message方法.

Python
 
class DocumentUpdateView(FormMessageMixin, UpdateView):
    model = Document
    fields = ('name', )
    success_url = reverse_lazy('documents')
    form_valid_message = 'The document was successfully updated!'
    form_invalid_message = 'There are some errors in the form below.'

Django 1.9开始, 内置的LoginRequiredMixin和UserPassesTestMixin. 如果你要在视图中使用它们, 它们始终位于最左侧:

Python
Mixins在左,View在后
class DocumentUpdateView(LoginRequiredMixin, FormMessageMixin, UpdateView):
    model = Document
    fields = ('name', )
    success_url = reverse_lazy('documents')
    form_valid_message = 'The document was successfully updated!'
© JackeyGao.io 2018.