class Pagination(object)分页源码

class Pagination(object):

def init(self, current_page, all_count, per_page_num=10, pager_count=11):

"""

封装分页相关数据

:param current_page: 当前页

:param all_count: 数据库中的数据总条数

:param per_page_num: 每页显示的数据条数

:param pager_count: 最多显示的页码个数

    用法:

    queryset = model.objects.all()

    page_obj = Pagination(current_page,all_count)

    page_data = queryset[page_obj.start:page_obj.end]

    获取数据用page_data而不再使用原始的queryset

    获取前端分页样式用page_obj.page_html

    """

    try:

        current_page = int(current_page)

    except Exception as e:

        current_page = 1

    if current_page < 1:

        current_page = 1

    self.current_page = current_page

    self.all_count = all_count

    self.per_page_num = per_page_num

    # 总页码

    all_pager, tmp = divmod(all_count, per_page_num)

    if tmp:

        all_pager += 1

    self.all_pager = all_pager

    self.pager_count = pager_count

    self.pager_count_half = int((pager_count - 1) / 2)

@property

def start(self):

    return (self.current_page - 1) * self.per_page_num

@property

def end(self):

    return self.current_page * self.per_page_num

def page_html(self):

    # 如果总页码 < 11个：

    if self.all_pager <= self.pager_count:

        pager_start = 1

        pager_end = self.all_pager + 1

    # 总页码  > 11

    else:

        # 当前页如果<=页面上最多显示11/2个页码

        if self.current_page <= self.pager_count_half:

            pager_start = 1

            pager_end = self.pager_count + 1

        # 当前页大于5

        else:

            # 页码翻到最后

            if (self.current_page + self.pager_count_half) > self.all_pager:

                pager_end = self.all_pager + 1

                pager_start = self.all_pager - self.pager_count + 1

            else:

                pager_start = self.current_page - self.pager_count_half

                pager_end = self.current_page + self.pager_count_half + 1

    page_html_list = []

    # 添加前面的nav和ul标签

    page_html_list.append('''

                <nav aria-label='Page navigation>'

                <ul class='pagination'>

            ''')

    first_page = '<li><a href="?page=%s">首页</a></li>' % (1)

    page_html_list.append(first_page)

    if self.current_page <= 1:

        prev_page = '<li class="disabled"><a href="#">上一页</a></li>'

    else:

        prev_page = '<li><a href="?page=%s">上一页</a></li>' % (self.current_page - 1,)

    page_html_list.append(prev_page)

    for i in range(pager_start, pager_end):

        if i == self.current_page:

            temp = '<li class="active"><a href="?page=%s">%s</a></li>' % (i, i,)

        else:

            temp = '<li><a href="?page=%s">%s</a></li>' % (i, i,)

        page_html_list.append(temp)

    if self.current_page >= self.all_pager:

        next_page = '<li class="disabled"><a href="#">下一页</a></li>'

    else:

        next_page = '<li><a href="?page=%s">下一页</a></li>' % (self.current_page + 1,)

    page_html_list.append(next_page)

    last_page = '<li><a href="?page=%s">尾页</a></li>' % (self.all_pager,)

    page_html_list.append(last_page)

    # 尾部添加标签

    page_html_list.append('''

                                       </nav>

                                       </ul>

                                   ''')

    return ''.join(page_html_list)