06-02 分页器组件 - 图1

    1. class Pagination(object):
    2.     def __init__(self,current_page,all_count,per_page_num=2,pager_count=11):
    3.         """
    4.         封装分页相关数据
    5.         :param current_page: 当前页
    6.         :param all_count:    数据库中的数据总条数
    7.         :param per_page_num: 每页显示的数据条数
    8.         :param pager_count:  最多显示的页码个数
    10.         用法:
    11.         queryset = model.objects.all()
    12.         page_obj = Pagination(current_page,all_count)
    13.         page_data = queryset[page_obj.start:page_obj.end]
    14.         获取数据用page_data而不再使用原始的queryset
    15.         获取前端分页样式用page_obj.page_html
    16.         """
    17.         try:
    18.             current_page = int(current_page)
    19.         except Exception as e:
    20.             current_page = 1
    22.         if current_page <1:
    23.             current_page = 1
    25.         self.current_page = current_page
    27.         self.all_count = all_count
    28.         self.per_page_num = per_page_num
    31.         # 总页码
    32.         all_pager, tmp = divmod(all_count, per_page_num)
    33.         if tmp:
    34.             all_pager += 1
    35.         self.all_pager = all_pager
    37.         self.pager_count = pager_count
    38.         self.pager_count_half = int((pager_count - 1) / 2)
    40.     @property
    41.     def start(self):
    42.         return (self.current_page - 1) * self.per_page_num
    44.     @property
    45.     def end(self):
    46.         return self.current_page * self.per_page_num
    48.     def page_html(self):
    49.         # 如果总页码 < 11个：
    50.         if self.all_pager <= self.pager_count:
    51.             pager_start = 1
    52.             pager_end = self.all_pager + 1
    53.         # 总页码  > 11
    54.         else:
    55.             # 当前页如果<=页面上最多显示11/2个页码
    56.             if self.current_page <= self.pager_count_half:
    57.                 pager_start = 1
    58.                 pager_end = self.pager_count + 1
    60.             # 当前页大于5
    61.             else:
    62.                 # 页码翻到最后
    63.                 if (self.current_page + self.pager_count_half) > self.all_pager:
    64.                     pager_end = self.all_pager + 1
    65.                     pager_start = self.all_pager - self.pager_count + 1
    66.                 else:
    67.                     pager_start = self.current_page - self.pager_count_half
    68.                     pager_end = self.current_page + self.pager_count_half + 1
    70.         page_html_list = []
    71.         # 添加前面的nav和ul标签
    72.         page_html_list.append('''
    73.                     <nav aria-label='Page navigation>'
    74.                     <ul class='pagination'>
    75.                 ''')
    76.         first_page = '<li><a href="?page=%s">首页</a></li>' % (1)
    77.         page_html_list.append(first_page)
    79.         if self.current_page <= 1:
    80.             prev_page = '<li class="disabled"><a href="#">上一页</a></li>'
    81.         else:
    82.             prev_page = '<li><a href="?page=%s">上一页</a></li>' % (self.current_page - 1,)
    84.         page_html_list.append(prev_page)
    86.         for i in range(pager_start, pager_end):
    87.             if i == self.current_page:
    88.                 temp = '<li class="active"><a href="?page=%s">%s</a></li>' % (i, i,)
    89.             else:
    90.                 temp = '<li><a href="?page=%s">%s</a></li>' % (i, i,)
    91.             page_html_list.append(temp)
    93.         if self.current_page >= self.all_pager:
    94.             next_page = '<li class="disabled"><a href="#">下一页</a></li>'
    95.         else:
    96.             next_page = '<li><a href="?page=%s">下一页</a></li>' % (self.current_page + 1,)
    97.         page_html_list.append(next_page)
    99.         last_page = '<li><a href="?page=%s">尾页</a></li>' % (self.all_pager,)
    100.         page_html_list.append(last_page)
    101.         # 尾部添加标签
    102.         page_html_list.append('''
    103.                                            </nav>
    104.                                            </ul>
    105.                                        ''')
    106.         return ''.join(page_html_list)