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25 Jun 18

https://www.cnblogs.com/liwenzhou/p/8343243.html

一、分页

# 利用URL携带参数page,views.py中通过request.GET来获取page参数

# utils: 放常用工具

 

  1. 在工具包utils中自定义mypage,并用其完成分页显示(推荐使用)

book_list.html

<!DOCTYPE html>

<html lang="en">

<head>

    <meta charset="UTF-8">

    <meta name="viewport" content="width=device-width, initial-scale=1">

   <title>Book_list</title>

    <link rel="stylesheet" href="/static/bootstrap-3.3.7/css/bootstrap.min.css">

</head>

<body>

<h1>Book List</h1>

<div class="container">

    <table class="table table-bordered">

        <thead>

        <tr>

           <th>#</th>

           <th>Title</th>

            <th>Publish Date</th>

        </tr>

        </thead>

        <tbody>

        {% for book in book_list %}

            <tr>

                <td>{{ forloop.counter }}</td>

                <td>{{ book.title }}</td>

                <td>{{ book.publish_date|date:'Y-m-d'}}</td>  # 格式化输出日期

            </tr>

        {% endfor %}

        </tbody>

    </table>

</div>

 

<nav aria-label="Page navigation" class="text-center">

    <ul class="pagination">

        {{ page_html|safe}}  # 取消浏览器自动转译功能

    </ul>

</nav>

<script src="/static/jquery-3.3.1.min.js"></script>

<script src="/static/bootstrap-3.3.7/js/bootstrap.min.js"></script>

</body>

</html>

 

views.py

from django.shortcuts import render

from app01 import models

from utils import mypage

 

# 用工具包utils中的自定义mypage,完成分页显示

def book_list(request):

    data = models.Book.objects.all()

    total_num = data.count()

    current_page = request.GET.get('page')

    page_obj=mypage.Page(total_num, current_page, 'book_list',per_page=20)

    book_list = data[page_obj.data_start:page_obj.data_end]

    page_html = page_obj.page_html()

    return render(request, "book_List.html", {'book_list':book_list, 'page_html':page_html})

 

utils -> mypage.py. (小工具,可反复使用)

class Page(object):

    """

    这是一个自定义分页类

    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  #当前页面highlight,左右对称排列

    """

 

    def __init__(self, total_num, current_page, url_prefix, 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

        self.per_page = per_page

        self.show_page_num = show_page_num

 

       self.half_show_page_num = self.show_page_num // 2

 

        total_page, more = divmod(self.total_num, self.per_page) # divmod()得到商和余数的小元组

        if more:

            total_page += 1

        self.total_page = total_page

 

        try:

            current_page = int(current_page)  # GET得到的current_page是字符串,必须要转成int才能进行后续运算操作

        except Exception as e:

            current_page = 1

        if current_page > self.total_page:

            current_page = self.total_page

        if current_page < 1:

            current_page = 1

        self.current_page = current_page

 

        if self.current_page - self.half_show_page_num <= 1:

            page_start = 1

            page_end = self.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

 

    @property # 将方法装饰成数据属性

    def data_start(self):

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

 

    @property

    def data_end(self):

        return (self.current_page)*self.per_page

 

    def page_html(self):

        li_list = []

       li_list.append('<li><a href="/{}/?page=1">首页</a></li>'.format(self.url_prefix))

        if self.current_page <= 1:

            prev_html = '<li class="disabled"><a aria-label="Previous"><span aria-hidden="true">&laquo;</span></a></li>'  # disabled,当在第一页时不能选前一页

        else:

            prev_html = '<li><a href="/{}/?page={}" aria_label="Previous"><span aria-hidden="true">&laquo;</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)# active,当前页highlight

            else:

                tmp = '<li><a href="/{0}/?page={1}">{1}</a></li>'.format(self.url_prefix,i)

           li_list.append(tmp)

        if self.current_page >= self.total_page:

            next_html = '<li class="disabled"><a aria-label="Previous"><span aria-hidden="true">&raquo;</span></a></li>'

        else:

            next_html = '<li><a href="/{}/?page={}" aria_label="Previous"><span aria-hidden="true">&raquo;</span></a></li>'.format(

               self.url_prefix, self.current_page + 1)

       li_list.append(next_html)

       li_list.append('<li><a href="/{}/?page={}">尾页</a></li>'.format(self.url_prefix,self.total_page))

 

        page_html = "".join(li_list)  # 连成一个大的字符串,传至前段,方便后续操作

        return page_html

 

  1. 用Django中的分页,完成显示

views.py

# 用django中的工具,完成分页显示;功能单薄,一般不用

from django.core.paginator import Paginator,EmptyPage,PageNotAnInteger

def publisher_list(request):

    data = models.Publisher.objects.all()

    current_page = request.GET.get('page')

    page_obj = Paginator(data,10)

    try:

        publisher_list = page_obj.page(current_page)

        # has_next              是否有下一页

        # next_page_number      下一页页码

        # has_previous          是否有上一页

        # previous_page_number  上一页页码

        # object_list           分页之后的数据列表

        # number                当前页

        # paginator             paginator对象

    except PageNotAnInteger:

        publisher_list= page_obj.page(1)

    except EmptyPage:

        publisher_list = page_obj.page(page_obj.num_pages)

return render(request,'publisher_list.html',{'publisher_list':publisher_list})

 

publisher_list.html

<!DOCTYPE html>

<html lang="en">

<head>

    <meta charset="UTF-8">

    <meta name="viewport" content="width=device-width, initial-scale=1">

   <title>Publisher_list</title>

    <link rel="stylesheet" href="/static/bootstrap-3.3.7/css/bootstrap.min.css">

</head>

<body>

<h1>Publisher List</h1>

<div class="container">

    <table class="table table-bordered">

        <thead>

        <tr>

           <th>#</th>

            <th>Publish Name</th>

        </tr>

        </thead>

        <tbody>

        {% for publisher in publisher_list %}

            <tr>

                <td>{{ forloop.counter }}</td>

                <td>{{ publisher.name }}</td>

            </tr>

        {% endfor %}

        </tbody>

    </table>

 

    <nav aria-label="Page navigation">

        <ul class="pagination">

            {% if publisher_list.has_previous%}

                <li>

                    <a href="/publisher_list/?page={{ publisher_list.previous_page_number}}" aria-label="Previous">

                       <span aria-hidden="true">&laquo;</span>

                    </a>

                </li>

            {% else %}

                <li class="disabled">

                    <a aria-label="Previous">

                       <span aria-hidden="true">&laquo;</span>

                    </a>

                </li>

            {% endif %}

            <li class="active"><a href="#">{{ publisher_list.number }}</a></li>

            {% if publisher_list.has_next%}

                <li>

                    <a href="/publisher_list/?page={{ publisher_list.next_page_number}}" aria-label="Next">

                       <span aria-hidden="true">&raquo;</span>

                    </a>

                </li>

            {% else %}

                <li class="disabled">

                    <a aria-label="Next">

                       <span aria-hidden="true">&raquo;</span>

                    </a>

                </li>

            {% endif %}

        </ul>

    </nav>

</div>

<script src="/static/jquery-3.3.1.min.js"></script>

<script src="/static/bootstrap-3.3.7/js/bootstrap.min.js"></script>

</body>

 

二、Cookie

HTTP无状态-> Cookie

Cookie:服务端在返回响应的时候设置的,保存在浏览器上的键值对。

 

复习:  

print(request.path_info)  # 获得路径

print(request.get_full_path())  # 获得路径+参数

 

 

login.html

<!DOCTYPE html>

<html lang="en">

<head>

    <meta charset="UTF-8">

    <meta name="viewport" content="width=device-width, initial-scale=1">

   <title>Title</title>

</head>

<body>

<form action="{{ request.get_full_path }}" method="post">

    {% csrf_token %}

    <p>Username: <input type="text" name = "username"></p>

    <p>Password: <input type="password" name="pwd"></p>

    <p><input type="submit" value="Login"></p>

</form>

</body>

</html>

 

views.py

from django.shortcuts import render

from django.shortcuts import HttpResponse,render,redirect

from app01 import models

from utils import mypage

 

# 定义一个检测是否登陆的装饰器

def check_login(func):

    def wrapper(request,*args,**kwargs):

        login_flag = request.get_signed_cookie("login",default="",salt="shanghais1hao")  # 获取Cookie,加盐版的盐要一致

        # login_flag = request.COOKIES.get("login", "")  

#获取Cookie,非加盐版

 

        # default: 默认值

        # salt: 加密盐

        # max_age: 后台控制过期时间

 

        if login_flag.upper() == 'OK':

            return func(request,*args,**kwargs)

        else:

            url = request.path_info  # 获取跳转源路径

            return redirect("/login/?next={}".format(url))  # 如果是从其他页面跳转来,记录下该页面,完成验证后跳转回去

    return wrapper

 

# 用工具包utils中的自定义mypage,完成分页显示

@check_login

def book_list(request):

    data = models.Book.objects.all()

    total_num = data.count()

    current_page = request.GET.get('page')

   page_obj=mypage.Page(total_num, current_page, 'book_list',per_page=20)

    book_list = data[page_obj.data_start:page_obj.data_end]

    page_html = page_obj.page_html()

    return render(request, "book_List.html", {'book_list':book_list, 'page_html':page_html})

 

def login(request):

    if request.method == 'POST':

        username = request.POST.get('username')

        pwd = request.POST.get('pwd')

        if username == 'alex' and pwd =='alex':

            url = request.GET.get('next')  # 如果是从其他页面跳转来,跳转至该页面

            if not url:

                url = '/publisher_list/'  # 若非从其他页面跳转来的,跳转到默认页面

            rep = redirect(url)

            rep.set_signed_cookie("login","ok",salt="shanghais1hao")  

# 给响应设置Cookie,加密盐版

            # rep.set_cookie("login", "ok")  

# 给响应设置Cookie

 

            # 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)

 

            return rep

    return render(request,"login.html")

 

def logout(request):

    rep = redirect('/login/')

    rep.delete_cookie('login')  # 删除用户浏览器上之前设置的cookie值

    return rep

 

三、Session

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。

# 用session前要现有一个数据库(一定要执行makemigrations, migrate两条命令,即使models无变化)

1. 浏览器请求来了之后,服务端给你分配一个序号(口令)(程序级别完成)

2. 浏览器收到响应之后,把得到的口令保存在cookie (浏览器自带)

3. 浏览器携带着刚才得到的口令,再次发送请求 (浏览器自带)

4. 服务端拿到口令,去后端根据口令找对应的数据(大字典)(程序级别完成)

 

views.py

def login(request):

    err_msg = ""

    if request.method == 'POST':

        username = request.POST.get('username')

        pwd = request.POST.get('pwd')

        is_exist = models.User.objects.filter(name=username,pwd=pwd)

        if is_exist:

            # 登陆成功

            # 1. 生成随机字符串(口令),给浏览器返回

            # 2. 在服务端开辟一块空间,用来保存对应的session数据(大字典)

            # 3. 在服务端开辟的空间中保存需要保存的键值对数据

            request.session['login'] = 'OK'

            request.session['user'] = username  # 可以插入不只一条数据

            request.session.set_expiry(60*60*24*14)  # 两周,python支持上述写法

            return redirect('/index/')

        else:

            err_msg = 'invalid username or password'

    return render(request,'login.html',{'err_msg':err_msg})

 

def index(request):

    # 1. 判断请求中是否携带了我下发的随机字符串(口令)

    # 2. 拿着口令去后端找对应的session数据

    # 3. 根据固定的key去取固定的值

    login_flag = request.session.get('login')

    if login_flag == 'OK':

        return render(request,'index.html')

    else:

        return redirect('/login/')

 

def logout(request):

    request.session.flush()  # 删除当前的会话数据并删除会话的Cookie

    return redirect('/login/')

 

总结:

# 获取、设置、删除Session中数据

request.session['k1']

request.session.get('k1',None)

request.session['k1'] = 123

request.session.setdefault('k1',123) # 存在则不设置

del request.session['k1']

 

# 所有 键、值、键值对

request.session.keys()

request.session.values()

request.session.items()

request.session.iterkeys()

request.session.itervalues()

request.session.iteritems()

 

# 会话session的key

request.session.session_key

 

# 将所有Session失效日期小于当前日期的数据删除

request.session.clear_expired()  # session数据库中的数据不会自动清除,需手动删除

 

# 检查会话session的key在数据库中是否存在

request.session.exists("session_key")

 

# 删除当前会话的所有Session数据

request.session.delete()

  

# 删除当前的会话数据并删除会话的Cookie。

request.session.flush()  # 推荐使用

这用于确保前面的会话数据不可以再次被用户的浏览器访问

例如,django.contrib.auth.logout() 函数中就会调用它。

 

# 设置会话Session和Cookie的超时时间

request.session.set_expiry(value)

* 如果value是个整数,session会在些秒数后失效。

* 如果value是个datatime或timedelta,session就会在这个时间后失效。

* 如果value是0,用户关闭浏览器session就会失效。

* 如果value是None,session会依赖全局session失效策略。

 

四、CBV中加装饰器(Django内置的把函数装饰器转换成方法装饰器)

方式一:加载CBV视图的get或post方法上

views.py

from django import views

from django.utils.decorators import method_decorator

 

class Home(views.View):

    @method_decorator(check_login)

    def get(self, request):

        return render(request, "home.html")

    def post(self):

        pass

 

urls.py

urlpatterns = [

    url(r'^home/',views.Home.as_view()),

]

 

方式二:加载dispatch方法上

# 因为CBV中首先执行的就是dispatch方法,所以这么写相当于给get和post方法都加上了登录校验。

from django.utils.decorators import method_decorator

class HomeView(View):

    @method_decorator(check_login)

    def dispatch(self, request, *args, **kwargs):

        return super(HomeView, self).dispatch(request, *args, **kwargs)

 

    def get(self, request):

        return render(request, "home.html")

 

    def post(self, request):

        print("Home View POST method...")

        return redirect("/index/")

 

方式三:直接加在视图类上,但method_decorator必须传name 关键字参数

from django.utils.decorators import method_decorator

 

@method_decorator(check_login, name="get")

@method_decorator(check_login, name="post")

class HomeView(View):

    def dispatch(self, request, *args, **kwargs):

        return super(HomeView, self).dispatch(request, *args, **kwargs)

 

    def get(self, request):

        return render(request, "home.html")

 

    def post(self, request):

        print("Home View POST method...")

        return redirect("/index/")

 

五、CSRF Token相关装饰器(csrf_exempt,csrf_protect)

CSRF Token相关装饰器在CBV只能加到dispatch方法上

csrf_protect:为当前函数强制设置防跨站请求伪造功能,即便settings没设置全局中间件。

csrf_exempt,取消当前函数防跨站请求伪造功能,即便settings中设置了全局中间件。

 

views.py

from django.views.decorators.csrf import csrf_exempt, csrf_protect

@csrf_exempt

def login(request):

    err_msg = ""

    if request.method == 'POST':

        username = request.POST.get('username')

        pwd = request.POST.get('pwd')

        is_exist = models.User.objects.filter(name=username,pwd=pwd)

        if is_exist:

            # 登陆成功

            # 1. 生成随机字符串(口令),给浏览器返回

            # 2. 在服务端开辟一块空间,用来保存对应的session数据(大字典)

            # 3. 在服务端开辟的空间中保存需要保存的键值对数据

           request.session['login'] = 'OK'

           request.session['user'] = username # 可以插入不只一条数据

           request.session.set_expiry(60*60*24*14) # 两周,python支持上述写法

            return redirect('/index/')

        else:

            err_msg = 'invalid username or password'

return render(request,'login.html',{'err_msg':err_msg})

 

logins.html

<!DOCTYPE html>

<html lang="en">

<head>

    <meta charset="UTF-8">

    <meta name="viewport" content="width=device-width, initial-scale=1">

   <title>Title</title>

</head>

<body>

<form action="{{ request.get_full_path }}" method="post">

{#    {% csrf_token %}#}

    <p>Username: <input type="text" name = "username"></p>

    <p>Password: <input type="password" name="pwd"></p>

    <p><input type="submit" value="Login"></p>

    <p style="color:red">{{ err_msg }}</p>

</form>

</body>

</html>

 

六、其他

[链接]2018年不容错过的Django全栈项目YaDjangoBlog

https://zhuanlan.zhihu.com/p/33903527

 

七、补充

 

posted on 2018-06-25 20:10  zhangyaqian  阅读(153)  评论(0编辑  收藏  举报