分页
自定义分页
函数班
from django.shortcuts import render # Create your views here. data = [] for i in range(1, 302): tmp = {"id": i, "name": "alex-{}".format(i)} data.append(tmp) # data def user_list(request): try: page_num = int(request.GET.get("page")) # 字符串类型,所以要转成int except Exception as e: page_num = 1 # 没有传页码, 默认展示第一页 # if not page_num: # page_num = 1 # 每一页显示10条记录 per_page_num = 10 # user_list = data[0:10] 1 (1-1) *10 1*10 # user_list = data[10:20] 2 (2-1) *10 2*10 # user_list = data[20:30] 3 (n-1)*10 n*10 # 总数据个数 total_count = len(data) # 总共有多少页 total_page_num, more = divmod(total_count, per_page_num) if more: total_page_num += 1 # 如果你输入的页码数超过我的总页数,我默认返回最后一页 if page_num > total_page_num: page_num = total_page_num # 最多显示多少页码 max_show = 11 half_show = int((max_show-1)/2) # 页面上页码从哪儿开始 page_start = page_num - half_show # 页面上页码最多展示到哪一个 page_end = page_num + half_show # 如果当前页小于等于half_show, 默认从第一页展示到max_show if page_num <= half_show: page_start = 1 page_end = max_show # 如果当前页大于等于总页数-half_show if page_num >= total_page_num - half_show: page_end = total_page_num page_start = total_page_num - max_show # 生成前页码的HTML page_html_list = [] # 放置一个首页按钮 page_first_tmp = ‘<li><a href="/user_list/?page=1">首页</a></li>‘ page_html_list.append(page_first_tmp) # 加上一页按钮 if page_num - 1 <= 0: # 表示没有上一页 page_prev_tmp = ‘<li class="disabled" ><a href="#">上一页</a></li>‘ else: page_prev_tmp = ‘<li><a href="/user_list/?page={}">上一页</a></li>‘.format(page_num - 1) page_html_list.append(page_prev_tmp) for i in range(page_start, page_end+1): # 如果是当前页,就加一个active的样式 if i == page_num: tmp = ‘<li class="active"><a href="/user_list/?page={0}">{0}</a></li>‘.format(i) else: tmp = ‘<li><a href="/user_list/?page={0}">{0}</a></li>‘.format(i) page_html_list.append(tmp) # 加下一页按钮 if page_num+1 > total_page_num: page_next_tmp = ‘<li class="disabled"><a href="#">下一页</a></li>‘ else: page_next_tmp = ‘<li><a href="/user_list/?page={}">下一页</a></li>‘.format(page_num+1) page_html_list.append(page_next_tmp) # 添加一个尾页 page_last_tmp = ‘<li><a href="/user_list/?page={}">尾页</a></li>‘.format(total_page_num) page_html_list.append(page_last_tmp) page_html = "".join(page_html_list) # 去数据库取数据 start = (page_num - 1) * per_page_num end = page_num * per_page_num user_list = data[start:end] return render(request, "user_list.html", {"user_list": user_list, "page_html": page_html})
封装版
""" 这个文件的使用指南 """ class MyPage(object): def __init__(self, page_num, total_count, base_url, per_page_num=10, max_show=11): """ :param page_num: 当前页 :param total_count: 数据总个数 :param base_url: 分页页码跳转的URL :param per_page_num: 每一页显示多少条数据 :param max_show: 页面上最多显示多少页码 """ # 实例化时传进来的参数 try: self.page_num = int(page_num) # 字符串类型,所以要转成int except Exception as e: self.page_num = 1 self.total_count = total_count self.base_url = base_url self.per_page_num = per_page_num self.max_show = max_show # 根据传进来的参数,计算的几个值 self.half_show = int((self.max_show - 1) / 2) # 总共有多少页 self.total_page_num, more = divmod(self.total_count, self.per_page_num) if more: self.total_page_num += 1 @property def start(self): return (self.page_num - 1) * self.per_page_num @property def end(self): return self.page_num * self.per_page_num def page_html(self): """ 返回页面上可以用的一段HTML 一段可用的分页页码的HTML :return: """ # 页面上页码从哪儿开始 page_start = self.page_num - self.half_show # 页面上页码最多展示到哪一个 page_end = self.page_num + self.half_show # 如果当前页小于等于half_show, 默认从第一页展示到max_show if self.page_num <= self.half_show: page_start = 1 page_end = self.max_show # 如果当前页大于等于总页数-half_show if self.page_num >= self.total_page_num - self.half_show: page_end = self.total_page_num page_start = self.total_page_num - self.max_show # 生成前页码的HTML page_html_list = [] # 放置一个首页按钮 page_first_tmp = ‘<li><a href="{}?page=1">首页</a></li>‘.format( self.base_url) page_html_list.append(page_first_tmp) # 加上一页按钮 if self.page_num - 1 <= 0: # 表示没有上一页 page_prev_tmp = ‘<li class="disabled" ><a href="#">上一页</a></li>‘ else: page_prev_tmp = ‘<li><a href="{0}?page={1}">上一页</a></li>‘.format( self.base_url, self.page_num - 1) page_html_list.append(page_prev_tmp) for i in range(page_start, page_end+1): # 如果是当前页,就加一个active的样式 if i == self.page_num: tmp = ‘<li class="active"><a href="{0}?page={1}">{1}</a></li>‘.format( self.base_url, i) else: tmp = ‘<li><a href="{0}?page={1}">{1}</a></li>‘.format( self.base_url, i) page_html_list.append(tmp) # 加下一页按钮 if self.page_num+1 > self.total_page_num: page_next_tmp = ‘<li class="disabled"><a href="#">下一页</a></li>‘ else: page_next_tmp = ‘<li><a href="{0}?page={1}">下一页</a></li>‘.format( self.base_url, self.page_num+1) page_html_list.append(page_next_tmp) # 添加一个尾页 page_last_tmp = ‘<li><a href="{0}?page={1}">尾页</a></li>‘.format( self.base_url, self.total_page_num) page_html_list.append(page_last_tmp) return "".join(page_html_list)
封装版使用方法
def user_list(request): page_num = request.GET.get("page") path = request.path_info # request.get_full_path() # 带参数的URL from tools.mypage import MyPage page = MyPage(page_num, len(data), path) page_html = page.page_html() return render(request, "user_list.html", {"user_list": data[page.start:page.end], "page_html": page_html})
前端界面
{% load static %} <!DOCTYPE html> <html lang="zh-CN"> <head> <meta charset="UTF-8"> <meta http-equiv="x-ua-compatible" content="IE=edge"> <meta name="viewport" content="width=device-width, initial-scale=1"> <link rel="stylesheet" href="{% static "bootstrap-3.3.7/css/bootstrap.min.css" %}"> <title>用户列表</title> </head> <body> <div class="container"> <table class="table table-bordered"> <thead> <tr> <th>ID</th> <th>姓名</th> </tr> </thead> <tbody> {% for user in user_list %} <tr> <td>{{ user.id }}</td> <td>{{ user.name }}</td> </tr> {% endfor %} </tbody> </table> <div class="pull-right"> <nav aria-label="Page navigation"> <ul class="pagination"> {# {% for i in total_page_num %}#} {# <li><a href="/user_list/?page={{ i }}">{{ i }}</a></li>#} {# {% endfor %}#} {{ page_html|safe }} </ul> </nav> </div> </div> <script src="{% static "jquery-3.2.1.min.js" %}"></script> <script src="{% static "bootstrap-3.3.7/js/bootstrap.min.js" %}"></script> </body> </html>
Cookie和Session
简介
1、cookie不属于http协议范围,由于http协议无法保持状态,但实际情况,我们却又需要“保持状态”,因此cookie就是在这样一个场景下诞生。
cookie的工作原理是:由服务器产生内容,浏览器收到请求后保存在本地;当浏览器再次访问时,浏览器会自动带上cookie,这样服务器就能通过cookie的内容来判断这个是“谁”了。
2、cookie虽然在一定程度上解决了“保持状态”的需求,但是由于cookie本身最大支持4096字节,以及cookie本身保存在客户端,可能被拦截或窃取,因此就需要有一种新的东西,它能支持更多的字节,并且他保存在服务器,有较高的安全性。这就是session。
问题来了,基于http协议的无状态特征,服务器根本就不知道访问者是“谁”。那么上述的cookie就起到桥接的作用。
我们可以给每个客户端的cookie分配一个唯一的id,这样用户在访问时,通过cookie,服务器就知道来的人是“谁”。然后我们再根据不同的cookie的id,在服务器上保存一段时间的私密资料,如“账号密码”等等。
3、总结而言:cookie弥补了http无状态的不足,让服务器知道来的人是“谁”;但是cookie以文本的形式保存在本地,自身安全性较差;所以我们就通过cookie识别不同的用户,对应的在session里保存私密的信息以及超过4096字节的文本。
4、另外,上述所说的cookie和session其实是共通性的东西,不限于语言和框架
COOKIE
获取Cookie
request.COOKIES[‘key‘] request.get_signed_cookie(key, default=RAISE_ERROR, salt=‘‘, max_age=None)
参数:
default: 默认值
salt: 加密盐
max_age: 后台控制过期时间
设置Cookie
rep = HttpResponse(...) rep = render(request, ...) rep.set_cookie(key,value,...) rep.set_signed_cookie(key,value,salt=‘加密盐‘,...)
参数:
key, 键
value=‘‘, 值
max_age=None, 超时时间
expires=None, 超时时间(IE requires expires, so set it if hasn‘t been already.)
path=‘/‘, Cookie生效的路径,/ 表示根路径,特殊的:根路径的cookie可以被任何url的页面访问
domain=None, Cookie生效的域名
secure=False, https传输
httponly=False 只能http协议传输,无法被JavaScript获取(不是绝对,底层抓包可以获取到也可以被覆盖)
使用示例
view code
def login(request): if request.method == "POST": user = request.POST.get("user") pwd = request.POST.get("pwd") # 校验用户名密码 if user == "alex" and pwd == "dashabi": rep = redirect("/index/") # rep.set_cookie("user", user) 明文的 # import datetime # now = datetime.datetime.now() # d = datetime.timedelta(seconds=10) # rep.set_signed_cookie("user", user, salt="S8", expires=now+d) # 加盐处理,expires失效的具体时间 rep.set_signed_cookie("user", user, salt="S8", max_age=10) # 加盐处理,max_age有效期10秒 return rep return render(request, "login.html") def index(request): # username = request.COOKIES.get("user") 取明文 username = request.get_signed_cookie("user", None, salt="S8") # 取加盐的 if not username: # 表示没有登录 return redirect("/login/") return render(request, "index.html", {"username": username})
Cookie版登陆校验
view code
def check_login(func): @wraps(func) def inner(request, *args, **kwargs): next_url = request.get_full_path() if request.get_signed_cookie("login", salt="SSS", default=None) == "yes": # 已经登录的用户... return func(request, *args, **kwargs) else: # 没有登录的用户,跳转刚到登录页面 return redirect("/login/?next={}".format(next_url)) return inner def login(request): if request.method == "POST": username = request.POST.get("username") passwd = request.POST.get("password") if username == "xxx" and passwd == "dashabi": next_url = request.GET.get("next") if next_url and next_url != "/logout/": response = redirect(next_url) else: response = redirect("/class_list/") response.set_signed_cookie("login", "yes", salt="SSS") return response return render(request, "login.html")
原文地址:https://www.cnblogs.com/QQ279366/p/8353118.html