django 원본 해석 유니버설 보기 편의ListView
29121 단어 django 일반 보기
， ， 。 。계승 방식
graph TD
ListView[ListView] --> | | MultipleObjectTemplateResponseMixin(MultipleObjectTemplateResponseMixin)
ListView --> | get | BaseListView(BaseListView)
MultipleObjectTemplateResponseMixin --> | | TemplateResponseMixin(TemplateResponseMixin)
BaseListView --> | | MultipleObjectMixin(MultipleObjectMixin)
BaseListView --> | |View(View)
MultipleObjectMixin -->| | ContextMixin(ContextMixin)ListView 프로세스
url는 Request 대상과 다른 사용자 정의 매개 변수를ListView에 전송합니다.View 부류는 초기화 방법을 실행하고 사용자 정의 변수를 클래스 속성에 추가하고 as 를 호출합니다view 방법은 요청 방식에 대한 처리 함수를 찾습니다. (BaseListView의 get 방법)get 방법은 페이지 나누기 여부를 판단하는 문장을 실행하고MultipleObjectMixin 클래스의 get 를 호출합니다context_데이터 방법(부류ContextMixin)은 조회 데이터를 가져오고TemplateResponseMixin의render 를 호출합니다.to_response 방법은 렌더링된 템플릿을 되돌려줍니다.Template Response Mixin에 필요한 템플릿 정보는 Multiple Object Template Response Mixin 클래스에서 정의됩니다.ListView 클래스는 다중 상속을 사용했고 각 상속은 부모 클래스에 대응하는 매개 변수 정보를 정의하여 결합성을 크게 낮추었다.
사용법
일반적인 매개변수:
지정된 질의 세트를 반환하고 템플릿을 렌더링합니다.
코드 해석
ContextMixin
주요 매개 변수
class ContextMixin:
"""
A default context mixin that passes the keyword arguments received by
get_context_data() as the template context.
"""
extra_context = None
def get_context_data(self, **kwargs):
if 'view' not in kwargs:
kwargs['view'] = self
if self.extra_context is not None:
kwargs.update(self.extra_context)
return kwargsMultipleObjectMixin
물려받다
ContextMixin에서 상속
주요 매개 변수
코드
class MultipleObjectMixin(ContextMixin):
"""A mixin for views manipulating multiple objects."""
allow_empty = True
queryset = None
model = None
paginate_by = None
paginate_orphans = 0
context_object_name = None
paginator_class = Paginator
page_kwarg = 'page'
ordering = None
def get_queryset(self):
"""
Return the list of items for this view.
The return value must be an iterable and may be an instance of
`QuerySet` in which case `QuerySet` specific behavior will be enabled.
"""
if self.queryset is not None:
queryset = self.queryset
if isinstance(queryset, QuerySet):
queryset = queryset.all()
elif self.model is not None:
queryset = self.model._default_manager.all()
else:
raise ImproperlyConfigured(
"%(cls)s is missing a QuerySet. Define "
"%(cls)s.model, %(cls)s.queryset, or override "
"%(cls)s.get_queryset()." % {
'cls': self.__class__.__name__
}
)
ordering = self.get_ordering()
if ordering:
if isinstance(ordering, str):
ordering = (ordering,)
queryset = queryset.order_by(*ordering)
return queryset
def get_ordering(self):
"""Return the field or fields to use for ordering the queryset."""
return self.ordering
def paginate_queryset(self, queryset, page_size):
"""Paginate the queryset, if needed."""
paginator = self.get_paginator(
queryset, page_size, orphans=self.get_paginate_orphans(),
allow_empty_first_page=self.get_allow_empty())
page_kwarg = self.page_kwarg
page = self.kwargs.get(page_kwarg) or self.request.GET.get(page_kwarg) or 1
try:
page_number = int(page)
except ValueError:
if page == 'last':
page_number = paginator.num_pages
else:
raise Http404(_("Page is not 'last', nor can it be converted to an int."))
try:
page = paginator.page(page_number)
return (paginator, page, page.object_list, page.has_other_pages())
except InvalidPage as e:
raise Http404(_('Invalid page (%(page_number)s): %(message)s') % {
'page_number': page_number,
'message': str(e)
})
def get_paginate_by(self, queryset):
"""
Get the number of items to paginate by, or ``None`` for no pagination.
"""
return self.paginate_by
def get_paginator(self, queryset, per_page, orphans=0,
allow_empty_first_page=True, **kwargs):
"""Return an instance of the paginator for this view."""
return self.paginator_class(
queryset, per_page, orphans=orphans,
allow_empty_first_page=allow_empty_first_page, **kwargs)
def get_paginate_orphans(self):
"""
Return the maximum number of orphans extend the last page by when
paginating.
"""
return self.paginate_orphans
def get_allow_empty(self):
"""
Return ``True`` if the view should display empty lists and ``False``
if a 404 should be raised instead.
"""
return self.allow_empty
def get_context_object_name(self, object_list):
"""Get the name of the item to be used in the context."""
if self.context_object_name:
return self.context_object_name
elif hasattr(object_list, 'model'):
return '%s_list' % object_list.model._meta.model_name
else:
return None
def get_context_data(self, *, object_list=None, **kwargs):
"""Get the context for this view."""
queryset = object_list if object_list is not None else self.object_list
page_size = self.get_paginate_by(queryset)
context_object_name = self.get_context_object_name(queryset)
if page_size:
paginator, page, queryset, is_paginated = self.paginate_queryset(queryset, page_size)
context = {
'paginator': paginator,
'page_obj': page,
'is_paginated': is_paginated,
'object_list': queryset
}
else:
context = {
'paginator': None,
'page_obj': None,
'is_paginated': False,
'object_list': queryset
}
if context_object_name is not None:
context[context_object_name] = queryset
context.update(kwargs)
return super().get_context_data(**context)View
주요 매개 변수
class View:
"""
Intentionally simple parent class for all views. Only implements
dispatch-by-method and simple sanity checking.
"""
http_method_names = ['get', 'post', 'put', 'patch', 'delete', 'head', 'options', 'trace']
def __init__(self, **kwargs):
"""
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 kwargs.items():
setattr(self, key, value)
@classonlymethod
def as_view(cls, **initkwargs):
"""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))
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
# take name and docstring from class
update_wrapper(view, cls, updated=())
# and possible attributes set by decorators
# like csrf_exempt from dispatch
update_wrapper(view, cls.dispatch, assigned=())
return view
def dispatch(self, request, *args, **kwargs):
# 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)
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 HttpResponseNotAllowed(self._allowed_methods())
def options(self, request, *args, **kwargs):
"""Handle responding to requests for the OPTIONS HTTP verb."""
response = HttpResponse()
response['Allow'] = ', '.join(self._allowed_methods())
response['Content-Length'] = '0'
return response
def _allowed_methods(self):
return [m.upper() for m in self.http_method_names if hasattr(self, m)]BaseListView
물려받다
MultipleObjectMixin 및 View에서 상속
기능 함수
코드
class BaseListView(MultipleObjectMixin, View):
"""A base view for displaying a list of objects."""
def get(self, request, *args, **kwargs):
self.object_list = self.get_queryset()
allow_empty = self.get_allow_empty()
if not allow_empty:
# When pagination is enabled and object_list is a queryset,
# it's better to do a cheap query than to load the unpaginated
# queryset in memory.
if self.get_paginate_by(self.object_list) is not None and hasattr(self.object_list, 'exists'):
is_empty = not self.object_list.exists()
else:
is_empty = len(self.object_list) == 0
if is_empty:
raise Http404(_("Empty list and '%(class_name)s.allow_empty' is False.") % {
'class_name': self.__class__.__name__,
})
context = self.get_context_data()
return self.render_to_response(context)MultipleObjectTemplateResponseMixin
물려받다
Template ResponseMixin에서 상속
주요 매개 변수
코드
class MultipleObjectTemplateResponseMixin(TemplateResponseMixin):
"""Mixin for responding with a template and list of objects."""
template_name_suffix = '_list'
def get_template_names(self):
"""
Return a list of template names to be used for the request. Must return
a list. May not be called if render_to_response is overridden.
"""
try:
names = super().get_template_names()
except ImproperlyConfigured:
# If template_name isn't specified, it's not a problem --
# we just start with an empty list.
names = []
# If the list is a queryset, we'll invent a template name based on the
# app and model name. This name gets put at the end of the template
# name list so that user-supplied names override the automatically-
# generated ones.
if hasattr(self.object_list, 'model'):
opts = self.object_list.model._meta
names.append("%s/%s%s.html" % (opts.app_label, opts.model_name, self.template_name_suffix))
return names
TemplateResponseMixin
주요 매개 변수
class TemplateResponseMixin:
"""A mixin that can be used to render a template."""
template_name = None
template_engine = None
response_class = TemplateResponse
content_type = None
def render_to_response(self, context, **response_kwargs):
"""
Return a response, using the `response_class` for this view, with a
template rendered with the given context.
Pass response_kwargs to the constructor of the response class.
"""
response_kwargs.setdefault('content_type', self.content_type)
return self.response_class(
request=self.request,
template=self.get_template_names(),
context=context,
using=self.template_engine,
**response_kwargs
)
def get_template_names(self):
"""
Return a list of template names to be used for the request. Must return
a list. May not be called if render_to_response() is overridden.
"""
if self.template_name is None:
raise ImproperlyConfigured(
"TemplateResponseMixin requires either a definition of "
"'template_name' or an implementation of 'get_template_names()'")
else:
return [self.template_name]좋은 웹페이지 즐겨찾기
