classbaseView.md

Xiang Wang @ 2016-08-04 19:02:28

ClasssBase View API 官网

基础

• 基础

from django.views.generic import View, ListView, DetailView, TemplateView
class ListView(ListView):
    model = Publisher
    template_name = 'appname/templates.html'
    paginate_by = 2 # 每页的数量
    http_method_names = ['get']
    context_object_name = 'my_favorite_publishers'  # 渲染用的名称

    def get_context_data(self):
        return {
            "paginator",
            "page_obj",
            "is_paginated",
            "object_list",
            "<modelname>_list",
        }

Base Views

• View
  • 参数
    • http_method_names = ["get", "post"] # 支持的参数
      • 默认 ['get', 'post', 'put', 'patch', 'delete', 'head', 'options', 'trace']
  • 方法
    • get
• TemplateView
  • 参数
    • template_name = "appname/filename.html" # 使用哪个html渲染
  • 方法
    • get_context_data
      • 返回一个dict, 用于渲染
      • 预定义的方法只是把view这个对象交给context['view']并没有其他操作
• RedirectView

from django.views.generic.base import RedirectView
path('go-to-django/', RedirectView.as_view(url='https://djangoproject.com'), name='go-to-django'),

Generic display views

• ListView

def get(self, request, *args, **kwargs):
    self.object_list = self.get_queryset()
    allow_empty = self.get_allow_empty()
    if not allow_empty:
        if self.get_paginate_by(self.object_list) is not None and hasattr(self.object_list, 'exists'):
            is_empty = not self.objects.exists()
        else:
            is_empty = len(self.object_list) == 0
        if is_empty:
            raise Http404(_("字符串"))
    context = self.get_context_data()
    return self.render_to_response(context)

• DetailView

from django.views.generic.detail import DetailView
class ArticleDetailView(DetailView):
    model = Article

Generic editing views

• CreateView

  1. BaseCreateView.post(self, request, *args, **kwargs):

     self.object = None
     super
     

  2. ProcessFormView.post(self, request, *args, **kwargs):

     form = self.get_form()
     if form.is_valid():
         return self.form_valid(form)
     else:
         return self.form_invalid(form)
     

     1. FormMixin.get_form(self, form_class=None)

        if form_class is None:
            form_class = self.get_form_class()
        return form_class(**self.get_form_kwargs())
        

     2. ModelFormMixin.get_form_kwargs:

        kwargs = super(ModelFormMixin, self).get_form_kwargs()
        if hasattr(self, 'object'):
            kwargs.update({'instance': self.object})
        return kwargs
        

     3. FormMixin.get_form_kwargs(self):

        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                               
        

  3. 如果成功

     1. ModelFormMixin.form_valid(self, form):

        self.object=form.save()
        return super(ModelFormMixin, self).form_valid(form)
        

     2. FormMixin.form_valid(self, form):
return HttpResponseRedirect(self.get_success_url())

  4. 如果失败

     1. FormMixin.form_invalid(self, form):
return self.render_to_response(self.get_context_data())

• UpdateView

  • 参数
  • 执行过程

    def self.post(self, request, *args, **kwargs)
        self.object = self.get_object()
        return super(BaseUpdateView, self).post(request, *args, **kwargs)
    def BaseUpdateView.post(self, request, *args, **kwargs)
        form = self.get_form()
        if form.is_valid():
            return self.form_valid(form)
    def form_valid(self, form):
        self.object = form.save()
        return super(ModelFormMixin, self).form_valid(form)
    

Class-based views mixins

Simple mixins

• Context mixins
  • extra_context: TemplateView.as_view(extra_context={"title": "Common Title"})
  • get_context_data:

  from django.views.generic.base import ContextMixin
  def get_context_data(self, **kwargs):
      if "view" not in kwargs:
          kwargs["view"] = self
      return kwargs
  def get_context_data(self, **kwargs):
      context = super(TemplateView, self).get_context_data(**kwargs)
      context["number"] = random.randrange(1, 100)
      return context
  

• TemplateResponseMixin django.views.generic.base.TemplateResponseMixin
  • get_template_names() 返回一个template的列表用于渲染

  def get_template_names(self):
      if self.template_name is None:
          raisee ImproperlyConfigured(
              "TemplateResponseMixin requires either a definition of "
              "'template_name' or an implementation of 'get_template_names()'")
      else:
          return [self.template_name]
  

  如果要自定义template, 根据url返回

  def get_template_names(self):
      if self.request.resolver_match.kwargs["scene"] == "admin":
          return ["admin_template.html"]
      else:
          return super(View, self).get_template_names()
  

Editing mixins

• FormMixin: django.views.generic.edit.FormMixin
  • form_valid: redirects to get_success_url()

  return HttpResponseRedirect(self.get_success_url())
  

  • form_invalid:

  return self.render_to_response(self.get_context_data(form=form))
  

• ModelFormMixin(FormMixin, SingleObjectMixin): django.views.generic.edit.ModelFormMixin
  • form_valid

  def form_valid(self, form):
      self.object = form.save()
      return super().form_valid(form)
  

  • get_success_url: 数据创建成功后跳转的页面

  def get_success_url(self):
      if self.success_url:
          url = self.success_url.format(**self.object.__dict__)
      else:
          try:
              url = self.object.get_absolute_url()
          except AttributeError:
              raise ImproperlyConfigured("...")
      return url