跟据上一篇的分页内容进行一个改进,好让以后写不同的分页的内容,不用从头写,只要拿过来用就好了。
自定义一个工具包utils在具下面创建一个mypage.py文件,在里面定义一个用于分页的类:
class Page(object):
"""
这是自定义分页类
可以实现Django ORM数据的分页展示
使用说明:
from utils import mypage
page_obj = mypage.Page(total_num, current_page, 'publisher_list')
publisher_list = data[page_obj.data_start:page_obj.data_end]
page_html = page_obj.page_html()
为了显示效果,show_page_num最好使用奇数
"""
def __init__(self, total_num, current_page, url_prefix='index', per_page=10, show_page_num=11):
"""
:param total_num: 数据的总条数
:param current_page: 当前访问的页码
:param url_prefix: 分页代码里a标签的前缀
:param per_page: 每一页显示多少条数据
:param show_page_num: 页面上最多显示多少个页码
"""
self.total_num = total_num
self.url_prefix = url_prefix
print(self.url_prefix)
self.per_page = per_page
self.show_page_num = show_page_num
# 通过初始化传入的值计算得到的值
self.half_show_page_num = self.show_page_num // 2
# 当前数据总共需要多少页码
total_page, more = divmod(self.total_num, self.per_page)
# 如果有余数,就把页码数+1
if more:
total_page += 1
self.total_page = total_page
# 对传进来的当前页码数做有效性校验
try:
current_page = int(current_page)
except Exception as e:
current_page = 1
# 如果当前页码数大于总页码数,默认展示最后一页的数据
# current_page = total_page if current_page > total_page else current_page
if current_page > self.total_page:
current_page = self.total_page
# 如果当前页码数小于1,默认展示第一页的数据
if current_page < 1:
current_page = 1
self.current_page = current_page
# 求 页面上 需要展示的页码范围
if self.current_page - self.half_show_page_num <= 1:
page_start = 1
page_end = show_page_num
elif self.current_page + self.half_show_page_num >= self.total_page:
page_end = self.total_page
page_start = self.total_page - self.show_page_num + 1
else:
page_start = self.current_page - self.half_show_page_num
page_end = self.current_page + self.half_show_page_num
self.page_start = page_start
self.page_end = page_end # 我上面一通计算得到的页面显示的页码结束
# 如果你一通计算的得到的页码数比我总共的页码数还多,我就把页码结束指定成我总共有的页码数
if self.page_end > self.total_page:
self.page_end = self.total_page
@property
def data_start(self):
# 返回当前页应该从哪儿开始切数据
return (self.current_page-1)*self.per_page
@property
def data_end(self):
# 返回当前页应该切到哪里为止
return self.current_page*self.per_page
def page_html(self):
li_list = []
# 添加前面的nav和ul标签
li_list.append("""
<nav aria-label="Page navigation">
<ul class="pagination">
""")
if not self.url_prefix:
self.url_prefix='index'
# 添加首页
li_list.append('<li><a href="/{}/?page=1">首页</a></li>'.format(self.url_prefix))
# 添加上一页
if self.current_page <= 1: # 没有上一页
prev_html = '<li class="disabled"><a aria-label="Previous"><span aria-hidden="true">«</span></a></li>'
else:
prev_html = '<li><a href="/{}/?page={}" aria-label="Previous"><span aria-hidden="true">«</span></a></li>'.format(self.url_prefix,
self.current_page - 1)
li_list.append(prev_html)
for i in range(self.page_start, self.page_end + 1):
if i == self.current_page:
tmp = '<li class="active"><a href="/{0}/?page={1}">{1}</a></li>'.format(self.url_prefix, i)
else:
tmp = '<li><a href="/{0}/?page={1}">{1}</a></li>'.format(self.url_prefix, i)
li_list.append(tmp)
# 添加下一页
if self.current_page >= self.total_page: # 表示没有下一页
next_html = '<li class="disabled"><a aria-label="Previous"><span aria-hidden="true">»</span></a></li>'
else:
next_html = '<li><a href="/{}/?page={}" aria-label="Previous"><span aria-hidden="true">»</span></a></li>'.format(
self.url_prefix, self.current_page + 1)
li_list.append(next_html)
# 添加尾页
li_list.append('<li><a href="/{}/?page={}">尾页</a></li>'.format(self.url_prefix, self.total_page))
# 添加nav和ul的结尾
li_list.append("""
</ul>
</nav>
""")
# 将生成的li标签 拼接成一个大的字符串
page_html = "".join(li_list)
return page_html
在views中使用这个类:
from django.shortcuts import render
from app01 import models
def book_list(request):
data = models.Book.objects.all()
# 总数据量
total_num = len(data)
current_page=request.GET.get("page")
from utils import mypage
page_obj=mypage.Page(total_num,current_page,'book_list',per_page=15)
# 当前页面要展示的书籍数据信息:
book_list = data[page_obj.data_start:page_obj.data_end]
return render(request, 'book_list.html', {'book_list': book_list,'page_html': page_obj.page_html})
效果: