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目錄
django.views.generic.TemplateView.. 1
django.views.generic.View.. 2
類的繼承和覆蓋：... 5
自定義LoginRequiredMixin：... 5
通用視圖：... 6
django.views.generic.ListView.. 6
django.views.generic.DetailView.. 8
django.views.generic.FormView：... 9
django.views.generic.CreateView：... 9
django.views.generic.UpdateView：... 9
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cbv，class based view：
基于類的視圖，使編寫view更簡潔，有復雜的繼承關系；
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CBV和FBV兩者各有優劣；
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UML圖；
Mixin增強功能，提供一些方法，如TemplateResponseMixin提供了render_to_response()渲染模板，ContextMixin提供get_context_data()；
View提供get,post訪問入口；
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例，ver1：
def about(request):?? #ver1，FBV用法
??? return render(request, 'blog/about.html')
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url(r'^about/', views.about, name='about'),
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例，ver2：
from django.views.generic import TemplateView
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app_name = 'blog'
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urlpatterns = [
??? url(r'^$', views.index, name='index'),
??? url(r'^login/', views.auth_login, name='login'),
??? url(r'^logout/', views.auth_logout, name='logout'),
??? # url(r'^about/', views.about, name='about'),
??? url(r'^about/', TemplateView.as_view(template_name='blog/about.html')),?? #ver2，CBV用法1
]
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例，ver3：
from django.views.generic import TemplateView
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class AboutView(TemplateView):?? #ver3，CBV用法2
template_name = 'blog/about.html'
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url(r'^about/', AboutView.as_view()),
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View源碼：
該類在沒更改原來django邏輯的情況下，可用于編寫view，每個http請求會使用對應類的同名的方法進行處理；
class View(object):
??? """
??? Intentionally simple parent class for all views. Only implements
??? dispatch-by-method and simple sanity checking.
??? """
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??? http_method_names = ['get', 'post', 'put', 'patch', 'delete', 'head', 'options', 'trace']
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??? def __init__(self, **kwargs):?? #檢查as_view()傳入的參數是否在類中定義
??????? """
??????? Constructor. Called in the URLconf; can contain helpful extra
??????? keyword arguments, and other things.
??????? """
??????? # Go through keyword arguments, and either save their values to our
??????? # instance, or raise an error.
??????? for key, value in six.iteritems(kwargs):
??????????? setattr(self, key, value)
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@classonlymethod
??? def as_view(cls, **initkwargs):?? #返回的是一個函數對象（裝飾器）；template_name=’blog/about.html’模板名作為參數傳，或在類屬性中定義，傳入的參數可覆蓋類中定義的屬性
??????? """
??????? Main entry point for a request-response process.
??????? """
??????? for key in initkwargs:
??????????? if key in cls.http_method_names:
??????????????? raise TypeError("You tried to pass in the %s method name as a "
??????????????????????????????? "keyword argument to %s(). Don't do that."
??????????????????????? ????????% (key, cls.__name__))
??????????? if not hasattr(cls, key):
??????????????? raise TypeError("%s() received an invalid keyword %r. as_view "
??????????????????????????????? "only accepts arguments that are already "
??????????????????????????????? "attributes of the class." % (cls.__name__, key))
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??????? def view(request, *args, **kwargs):
??????????? self = cls(**initkwargs)
??????????? if hasattr(self, 'get') and not hasattr(self, 'head'):
??????????????? self.head = self.get
??????????? self.request = request
??????????? self.args = args
??????????? self.kwargs = kwargs
??????????? return self.dispatch(request, *args, **kwargs)
??????? view.view_class = cls
??????? view.view_initkwargs = initkwargs
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??????? # take name and docstring from class
??????? update_wrapper(view, cls, updated=())
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??????? # and possible attributes set by decorators
??????? # like csrf_exempt from dispatch
??????? update_wrapper(view, cls.dispatch, assigned=())
??????? return view
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??? def dispatch(self, request, *args, **kwargs):?? #根據用戶的request method路由到get、post方法
??????? # Try to dispatch to the right method; if a method doesn't exist,
??????? # defer to the error handler. Also defer to the error handler if the
??????? # request method isn't on the approved list.
???? ???if request.method.lower() in self.http_method_names:
??????????? handler = getattr(self, request.method.lower(), self.http_method_not_allowed)
??????? else:
??????????? handler = self.http_method_not_allowed
??????? return handler(request, *args, **kwargs)
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??? def http_method_not_allowed(self, request, *args, **kwargs):
??????? logger.warning(
??????????? 'Method Not Allowed (%s): %s', request.method, request.path,
??????????? extra={'status_code': 405, 'request': request}
??????? )
??????? return http.HttpResponseNotAllowed(self._allowed_methods())
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??? def options(self, request, *args, **kwargs):
??????? """
??????? Handles responding to requests for the OPTIONS HTTP verb.
??????? """
??????? response = http.HttpResponse()
??????? response['Allow'] = ', '.join(self._allowed_methods())
??????? response['Content-Length'] = '0'
??????? return response
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??? def _allowed_methods(self):
??????? return [m.upper() for m in self.http_method_names if hasattr(self, m)]
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例，ver1，FBV：
def my_view(request):
??? if request.method == 'GET':
??????? return HttpResponse('get it')
??? elif request.method == 'POST':
??????? return HttpResponse('post it')
??? elif request.method == 'HEAD':
??????? return HttpResponse('head it')
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例，ver2，CBV，省去了if判斷：
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from django.views.generic import View
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class MyView(View):
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??? def get(self, request):
??????? return HttpResponse('get it')
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??? def post(self, request):
??????? return HttpResponse('post it')
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??? def head(self, request):
??????? return HttpResponse('head it')
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??? # url(r'^myview', views.my_view),
??? url(r'^myview', MyView.as_view()),
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class GreetingView(View):
??? greeting = 'good day'
??? def get(self, request):
??????? return HttpResponse(self.greeting)
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class MorningGreetingView(GreetingView):
??? greeting = 'morning to yo'
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class LoginRequiredMixin:
??? @classmethod
??? def as_view(cls, **initkwargs):
??????? view = super(LoginRequiredMixin, cls).as_view(**initkwargs)
??????? return login_required(view)
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class MyView(LoginRequiredMixin, View):
??? pass
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裝飾類：
from django.utils.decorators import method_decorator
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class ProtectedView(TemplateView):
??? template_name = 'blog/about.html'
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??? @method_decorator(login_required)
??? def dispatch(self, *args, **kwargs):
??????? return super(ProtectedView, self).dispatch(*args, **kwargs)
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generic class based view和class based view概念上不是一回事；
class based view是用類的方式寫view；
generic class based view是用class based view方式將常用的CRUD封裝成可擴展的類，使用時直接繼承，快速實現；
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多對象；
默認提供的上下文是object_list，也可用context_object_name指定；
queryset、get_queryset、model；
可指定template_name；
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例，ver1：
def publisher_list(request):
??? publishers = Publisher.objects.all()
??? return render(request, 'books/publishers.html', {'publishers': publishers})
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例，ver2：
from django.views.generic import ListView
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class PublisherList(ListView):?? #默認去找suffix為list的模板，即publisher_list.html；publisher_list.html模板；默認的context為object_list
??? model = Publisher?? #返回Publisher.object.all()，多對象
??? # template_name = 'books/publishers.html'?? #
???????? # context_object_name =??? #提供上下文
???????? # queryset = Publisher.objects.all()?? #model|queryset|get_queryset()三者關系
???????? # def get_queryset(self):
???????? #?????? return Publisher.objects.all()
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<body>
??? <ul>
??????? {% for publisher in object_list %}
??????? <h4>{{ publisher }}</h4>
??????? {% endfor %}
??? </ul>
</body>
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??? # url(r'^$', views.publisher_list, name='publishers'),
??? url(r'^$', PublisherList.as_view(), name='publisher'),
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單個對象的詳情；
get_context_data()；
context_object_name；
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<body>
??? <ul>
??????? <h4>{{ publisher }}</h4>
??????? {% for book in book_list %}
??????? {{ book }}<br/>
??????? {{ book.publisher }}
??????? {% endfor %}
??? </ul>
</body>
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from django.views.generic import DetailView
from .models import Book
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class PublisherDetail(DetailView):
??? model = Publisher
??? context_object_name = 'publisher'
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??? def get_context_data(self, **kwargs):
??????? context = super(PublisherDetail, self).get_context_data(**kwargs)
??????? context['book_list'] = Book.objects.all()
??????? return context
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??? url(r'^$', PublisherList.as_view(), name='publisher'),
??? url(r'^(?P<pk>[0-9]+)/$', PublisherDetail.as_view()),
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class PublisherForm(forms.Form):
??? name = forms.CharField(label=_('Your name'), max_length=30)
??? address = forms.CharField(max_length=50)
??? city = forms.CharField(max_length=60)
??? state_province = forms.CharField(max_length=30)
??? country = forms.CharField(max_length=20)
??? website = forms.CharField(max_length=50)
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??? def send_mail(self):
??????? print('~~~~~~~~~~~send_mail()?? OK')
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from django.views.generic import FormView
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class PublisherView(FormView):
??? form_class = PublisherForm
??? template_name = 'books/books_add.html'
??? success_url = '/books/'
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??? def form_valid(self, form):
??????? form.send_mail()
??????? return super(PublisherView, self).form_valid(form)
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??? url(r'^$', PublisherList.as_view(), name='publisher'),
url(r'^add', PublisherView.as_view()),
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根據model和fields動態構建form，另form_class = forms.AuthorForm等價于model和fields；
model + fields = form_class，另get_form_class、get_form；
template_name，不指定默認找suffix為_form.html；
success_url，get_success_url；
form_valid()、form_invalid()，注意重寫都要調用父類方法；
get_context_data；
success_message、get_success_message；
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from django.views.generic import CreateView
from .models import Author
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class AuthorCreate(CreateView):
??? model = Author
??? fields = ['first_name', 'last_name', 'email']
??? success_url = '/books/'
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??? def form_valid(self, form):
??????? return super().form_valid(form)
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??? def get_context_data(self, **kwargs):
??????? context = {'extra': 'some context'}
??????? kwargs.update(context)
??????? return super().get_context_data(**kwargs)
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??? url(r'^author/', AuthorCreate.as_view()),
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要有刪除確認頁面；
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