FormView 和 CreateView 有什么区别

Question

在官方文档中， formView 是显示表单的视图。出错时，重新显示带有验证错误的表单；成功后，重定向到一个新的 URL。 createView 是一个视图，它显示用于创建对象的表单，重新显示带有验证错误（如果有的话）的表单并保存对象。 //（也许我的英语不够好）所以如果我想为用户创建一个新类别创建一个通用视图，我应该使用 createview 而不是 formview 对吗？我不确定，所以我尝试了两种方法，但它们都给了我同样的错误：as_view() 只需要 1 个参数（给定 2 个）

带表单视图：

用于添加类别

class CategoryFormView(FormView):
    form_class = CategoryForm
    template_name = 'main/add_category.html'

    def get_success_url(self):
        return self.request.build_absolute_uri(reverse('category', args=[self.object.slug]))

    def get_context_data(self, **kwargs):
        context = super(CategoryFormView, self).get_context_data(**kwargs)
        # Add any extra context data needed for form here.
        return context

使用创建视图

#for adding category
class CategoryCreateView(CreateView):
    model = Category
    form_class = CategoryForm
    template_name = 'main/add_category.html'

    def form_valid(self, form):
      self.object = form.save(commit=False)
      #setting
      self.object.save()
      return HttpResponseRedirect(reverse('category', args=[self.object.slug]))

    @method_decorator(login_required)
    def dispatch(self, request, *args, **kwargs):
      return super(CategoryCreateView, self).dispatch(request, *args, **kwargs)
   

最后这是我的 urls.py

url(r'^add_category/', views.CategoryCreateView.as_view, name='add-category'),

编辑：对不起，它可以工作，只是忘记在 url 旁边放括号，但是你能告诉我 createview 和 formview 之间的区别吗？什么时候应该用什么？

编辑2：

def index(request):

    categories = Category.objects.order_by('likes')[:5]
    latest_posts = Post.objects.all().order_by('-created_at')
    popular_posts = Post.objects.all().order_by('-views')
    hot_posts = Post.objects.all().order_by('-score')[:25]
    context_dict = {
        'latest_posts': latest_posts,
        'popular_posts': popular_posts,
        'hot_posts': hot_posts,
        'categories': categories
    }
    return render(request, 'main/index.html', context_dict)
#for single-post page
#we use uuslug 
def post(request, slug):
    single_post = get_object_or_404(Post, slug=slug)
    single_post.views += 1  # increment the number of views
    single_post.save()      # and save it
    context_dict = {
      'single_post' :single_post,
    }
  
    return render(request, 'main/post.html', context_dict)
#for category page
#we use slugfield this time 
def category(request, category_name_slug):
  context_dict = {}
  try:
    category = Category.objects.get(slug=category_name_slug)
    context_dict['category_name'] = category.name

    posts = Post.objects.filter(category=category)
    context_dict['posts'] = posts
    context_dict['category'] = category
  except Category.DoesNotExist:
    pass

  return render(request, 'main/category.html', context_dict)
  

编辑 3

urls.py

from django.conf.urls import url
from main import views
from django.core.urlresolvers import reverse
from views import *

urlpatterns = [
    url(r'^$', IndexView.as_view(), name='index'),

    #url(r'^add_post/', views.add_post, name='add_post'),
    url(r'^add_post/$', PostCreateView.as_view(), name='post-add'),

    url(r'^(?P<slug>[\w|\-]+)/edit/$', PostUpdateView.as_view(), name='post-edit'),
    url(r'^(?P<slug>[\w|\-]+)/delete/$', PostDeleteView.as_view(), name='post-delete'),


    url(r'^add_category/$', CategoryCreateView.as_view(), name='add-category'),
    url(r'^(?P<slug>[\w|\-]+)/$', PostDetailView.as_view(), name='post'),

    url(r'^category/(?P<category_name_slug>[\w\-]+)/$', CategoryDetailView.as_view(), name='category'),
    
]

Answer 1

是的。您缺少函数调用：

url(r'^add_category/', views.CategoryCreateView.as_view(), name='add-category'),

至于你的另一个问题，CreateView 和FormView 非常相似，除了CreateView 是FormView 的更具体的实现。

FormView 真的是用来处理的：

• 在 GET 上显示表单
• 在 POST 上显示错误的表单
• 当表单没有错误时重定向到不同的页面

另一方面，CreateView 与 FormView 相同，只是它也这样做：

• 假设它正在处理实现save() 方法的ModelForm 表单
• 在重定向到其他页面之前，会调用表单的 save() 来创建模型
• 创建的模型存储在self.object中，以便您可以在get_success_url中使用它来为创建的对象生成URL（例如重定向到对象详细信息页面）

Classy 视图是检查 Django 基于类的视图的绝佳资源。以下是这两个课程的链接：

https://ccbv.co.uk/projects/Django/1.9/django.views.generic.edit/FormView/ https://ccbv.co.uk/projects/Django/1.9/django.views.generic.edit/CreateView/

查看我们的 form_valid 方法，您将看到最大的差异。

至于选择使用哪个，我认为这完全取决于您的情况。如果您尝试通过ModelForm 创建模型实例，那么CreateView 可能更适合您，如果您正在做一些通用的事情，那么FormView 可能更适合。

---

class IndexView(TemplateView):
    template_name = 'main/index.html'

    def get_context_data(self, **kwargs):
        context = super(IndexView, self).get_context_data(**kwargs)
        context.update({
            'latest_posts': Post.objects.all().order_by('-created_at'),
            'popular_posts': Post.objects.all().order_by('-views'),
            'hot_posts': Post.objects.all().order_by('-score')[:25],
            'categories': Category.objects.order_by('likes')[:5],
        })
        return context

class PostDetailView(DetailView):
    model = Post
    context_object_name = 'single_post'
    template_name = 'main/post.html'
    # note that these are already "slug" by default
    pk_url_kwarg = 'slug'
    slug_field = 'slug'

    def get_object(self, queryset=None):
        obj = seuper(PostView, self).get_object(queryset)
        obj.views += 1
        obj.save()
        return obj

class CategoryDetailView(DetailView):
    model = Category
    template_name = 'main/category.html'
    context_object_name = 'category'
    # note that these are already "slug" by default
    pk_url_kwarg = 'slug'
    slug_field = 'slug'

    def get_context_date(self, **kwargs):
        context = super(CategoryDetailView, self).get_context_data(**kwargs)
        context.update({
            # really no need to put category_name in context
            # as you can simply do {{ category.name }} in your template

            # you can use relations to query related data
            'posts': self.object.post_set.all()
        })
        return context