Django Version 1.6 View source analysis about list.py

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Source:Django Version 1.6 View source analysis about list.py

原址在上面 用Django 1.6搭建的 勉強能見人 嘿嘿 源碼分析看起來是不靠譜的 反正就是醬油的很 

class MultipleObjectMixin(ContextMixin):
    """
    A mixin for views manipulating multiple objects.
    """
    allow_empty = True
    queryset = None # 產生資料的queryset
    model = None   # 如果存在model，而queryset不存在 則  queryset = self.model._default_manager.all() 
    paginate_by = None # 分頁的每頁資料項目數
    paginate_orphans = 0
    context_object_name = None
    paginator_class = Paginator
    page_kwarg = ‘page‘ # 用於判決時第幾頁 page=self.kwargs.get(page_kwarg) or self.request.GET.get(page_kwarg) or 1


    def get_queryset(self):# 如果self.queryset存在則 返回如果存在model，而queryset不存在 則  queryset = self.model._default_manager.all() 
        """
        Get the list of items for this view. This must be an iterable, and may
        be a queryset (in which qs-specific behavior will be enabled).
若對於queryset無特殊要求 即只需要返回all()即可得 只需要賦值model的值即可
        """
        if self.queryset is not None:
            queryset = self.queryset
            if hasattr(queryset, ‘_clone‘):
                queryset = queryset._clone()
        elif self.model is not None:
            queryset = self.model._default_manager.all()
        else:
            raise ImproperlyConfigured("‘%s‘ must define ‘queryset‘ or ‘model‘"
                                       % self.__class__.__name__)
        return queryset


    def paginate_queryset(self, queryset, page_size):# 根據 paginate_by作為分頁的每頁資料項目數 ，並且指定頁數page = self.kwargs.get(page_kwarg) or self.request.GET.get(page_kwarg) or 1
        """
        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):
        """
        Returns the maximum number of orphans extend the last page by when
        paginating.
        """
        return self.paginate_orphans


    def get_allow_empty(self):
        """
        Returns ``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):# 返回 self.context_object_name 或者 hasattr(object_list, ‘model‘)-->return ‘%s_list‘ % object_list.model._meta.model_name
        """
        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, **kwargs): # 這個是為了get()函數self.object_list=get_query_set()--->queryset = kwargs.pop(‘object_list‘, self.object_list)
        """
        Get the context for this view.
        """
        queryset = kwargs.pop(‘object_list‘, 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(MultipleObjectMixin, self).get_context_data(**context)




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)




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(MultipleObjectTemplateResponseMixin, self).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




class ListView(MultipleObjectTemplateResponseMixin, BaseListView):
    """
    Render some list of objects, set by `self.model` or `self.queryset`.
    `self.queryset` can actually be any iterable of items, not just a queryset.
    """

Django Version 1.6 View source analysis about list.py