"""
分页组件使用示例：
1) 先取出所有数据USER_LIST
2) 实例化：
obj = Pagination(request.GET.get('page',1), len(USER_LIST), request)
3) 对所有数据列表切片（即切出一页数据）：
page_user_list = USER_LIST[obj.start:obj.end]
4) 返回给页面：
return render(request,'index.html',{'users': page_user_list, 'obj': obj})
5) 模板页面通过 {{ obj.page_html|safe }} 渲染页码
"""
class Pagination(object):
# 第一步 初始化页面
def __init__(self,current_page_num,all_count,request,per_page_num=5,pager_count=11):
"""
封装分页相关数据
:param current_page_num: 当前访问页的数字
:param all_count: 分页数据中的数据总条数
: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
"""
try:
current_page_num = int(current_page_num)
except Exception as e:
current_page_num = 1
if current_page_num <1:
current_page_num = 1
self.current_page_num = current_page_num
self.all_count = all_count
self.per_page_num = per_page_num
# 第二步 实际总页码
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) # 5
# 保存搜索条件
import copy
self.params=copy.deepcopy(request.GET) # {"a":"1","b":"2"}
@property #属性方法 在外部views里 切片的时候不用加括号 直接调用 start就可以
def start(self):
return (self.current_page_num - 1) * self.per_page_num
@property
def end(self):
return self.current_page_num * 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_num <= 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_num + self.pager_count_half) > self.all_pager:
pager_start = self.all_pager - self.pager_count + 1
pager_end = self.all_pager + 1
else:
pager_start = self.current_page_num - self.pager_count_half
pager_end = self.current_page_num + self.pager_count_half + 1
page_html_list = []
first_page = '<li><a href="?page=%s">首页</a></li>' % (1,)
page_html_list.append(first_page)
if self.current_page_num <= 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_num - 1,)
page_html_list.append(prev_page)
#self.params=copy.deepcopy(request.GET) # {"a":"1","b":"2"}
# 主要的for循环
for i in range(pager_start, pager_end):
self.params["page"]=i
if i == self.current_page_num:
temp = '<li class="active"><a href="?%s">%s</a></li>' %(self.params.urlencode(),i)
else:
temp = '<li><a href="?%s">%s</a></li>' % (self.params.urlencode(),i,)
page_html_list.append(temp)
if self.current_page_num >= 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_num + 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)
return ''.join(page_html_list)
