Django-choices字段值对应关系（性别）-MTV与MVC科普-Ajax发json格式与文件格式数据-contentType格式-Ajax搭配sweetalert实现删除确认弹窗-自定义分页器

from django.db import models


# Create your models here.
class User(models.Model):
    username = models.CharField(max_length=32)
    age = models.IntegerField()
    choices = (
        (1, '男'), (2, '女'), (3, '其他')
    )
    gender = models.IntegerField(choices=choices)

    """
    1 存choice里面罗列的数字与中文对应关系
         print(user_obj.get_gender_display())
            只要是choices字段 在获取数字对应的注释 固定语法
            get_choices字段名_display()

    2 存没有罗列迟来的数字
        不会报错 还是展示数字
    """


class Book(models.Model):
    title = models.CharField(max_length=32)

a 标签的 href 属性                   GET请求
直接在浏览器窗口输入 url 敲回车       GET请求
form 表单提交                       GET/POST
ajax 提交                           GET/POST

"""
Django settings for day57 project.

Generated by 'django-admin startproject' using Django 1.11.11.

For more information on this file, see
https://docs.djangoproject.com/en/1.11/topics/settings/

For the full list of settings and their values, see
https://docs.djangoproject.com/en/1.11/ref/settings/
"""

import os

# Build paths inside the project like this: os.path.join(BASE_DIR, ...)
BASE_DIR = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))


# Quick-start development settings - unsuitable for production
# See https://docs.djangoproject.com/en/1.11/howto/deployment/checklist/

# SECURITY WARNING: keep the secret key used in production secret!
SECRET_KEY = 'p0d7eiqh64wgd#!!rso@!wv#4w(%-)6%hb6q^4ci=+h54h@syx'

# SECURITY WARNING: don't run with debug turned on in production!
DEBUG = True

ALLOWED_HOSTS = []


# Application definition

INSTALLED_APPS = [
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
    'app01.apps.App01Config',  # 1.检查 APP 是否已注册
]

MIDDLEWARE = [
    'django.middleware.security.SecurityMiddleware',
    'django.contrib.sessions.middleware.SessionMiddleware',
    'django.middleware.common.CommonMiddleware',
    # 'django.middleware.csrf.CsrfViewMiddleware',  # 2.检查 csrf中间件 是否已注释掉
    'django.contrib.auth.middleware.AuthenticationMiddleware',
    'django.contrib.messages.middleware.MessageMiddleware',
    'django.middleware.clickjacking.XFrameOptionsMiddleware',
]

ROOT_URLCONF = 'day57.urls'

TEMPLATES = [
    {
        'BACKEND': 'django.template.backends.django.DjangoTemplates',
        'DIRS': [os.path.join(BASE_DIR, 'templates')]
        ,  # 3.检查 templates 文件夹是否已注册
        'APP_DIRS': True,
        'OPTIONS': {
            'context_processors': [
                'django.template.context_processors.debug',
                'django.template.context_processors.request',
                'django.contrib.auth.context_processors.auth',
                'django.contrib.messages.context_processors.messages',
            ],
        },
    },
]

WSGI_APPLICATION = 'day57.wsgi.application'


# Database
# https://docs.djangoproject.com/en/1.11/ref/settings/#databases

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.sqlite3',  # 4.检查 数据库配置信息(本文打算采用 django 自带的 sqlite3 进行测试，就不额外配置数据库了（__init__.py 文件里也就不配了）)
        'NAME': os.path.join(BASE_DIR, 'db.sqlite3'),
    }
}

LOGGING = {  # 5.添加数据库操作语句打印（一有数据库操作就会在 pycharm 控制台打印对应的 SQL 语句）
    'version': 1,
    'disable_existing_loggers': False,
    'handlers': {
        'console':{
            'level':'DEBUG',
            'class':'logging.StreamHandler',
        },
    },
    'loggers': {
        'django.db.backends': {
            'handlers': ['console'],
            'propagate': True,
            'level':'DEBUG',
        },
    }
}

# Password validation
# https://docs.djangoproject.com/en/1.11/ref/settings/#auth-password-validators

AUTH_PASSWORD_VALIDATORS = [
    {
        'NAME': 'django.contrib.auth.password_validation.UserAttributeSimilarityValidator',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.MinimumLengthValidator',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.CommonPasswordValidator',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.NumericPasswordValidator',
    },
]


# Internationalization
# https://docs.djangoproject.com/en/1.11/topics/i18n/

LANGUAGE_CODE = 'en-us'

TIME_ZONE = 'UTC'

USE_I18N = True

USE_L10N = True

USE_TZ = True


# Static files (CSS, JavaScript, Images)
# https://docs.djangoproject.com/en/1.11/howto/static-files/

STATIC_URL = '/static/'
STATICFILES_DIRS = [  # 6.配置静态资源路径（方便使用静态资源路径动态解析）
    os.path.join(BASE_DIR, 'static')
]

"""day57 URL Configuration

The `urlpatterns` list routes URLs to views. For more information please see:
    https://docs.djangoproject.com/en/1.11/topics/http/urls/
Examples:
Function views
    1. Add an import:  from my_app import views
    2. Add a URL to urlpatterns:  url(r'^$', views.home, name='home')
Class-based views
    1. Add an import:  from other_app.views import Home
    2. Add a URL to urlpatterns:  url(r'^$', Home.as_view(), name='home')
Including another URLconf
    1. Import the include() function: from django.conf.urls import url, include
    2. Add a URL to urlpatterns:  url(r'^blog/', include('blog.urls'))
"""
from django.conf.urls import url, include  # 下面用到了 include ，要自己导入这个模块
from django.contrib import admin

urlpatterns = [
    url(r'^admin/', admin.site.urls),
    url(r'^user/', include('app01.urls')),  # 写成字符串就会根据配置信息自动去查找，就不需要自己导模块过来了
]

from django.conf.urls import url
from django.contrib import admin
from app01 import views

urlpatterns = [
    url(r'^index/', views.index, name='user_index'),  # 匹配路由并取别名，方便后期反向解析 url
]

from django.shortcuts import render


# Create your views here.
def index(request):
    return render(request, 'index.html')  # 用户访问 http://127.0.0.1:8000/user/index/ 直接给他返回 index.html 这个页面

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>测试页</title>
{#    为了测试方便，这里就用网上的 jquery 了，用 CDN 的形式引入#}
    <script src="https://cdn.bootcss.com/jquery/3.4.1/jquery.min.js"></script>
{#    下面练习一下静态资源路径动态解析，并且 boostrap 放在本地会有语法提示，可以加快开发效率#}
    {% load static %}
    <link rel="stylesheet" href="{% static 'bootstrap-3.3.7-dist/css/bootstrap.min.css' %}">
    <script src="{% static 'bootstrap-3.3.7-dist/js/bootstrap.min.js' %}"></script>
</head>
<body>
{#随便搭一个页面#}
    <div class="container">
        <div class="row">
            <div class="text-center">
                <input type="text"> +
                <input type="text"> =
                <input type="text">
                <button class="btn btn-primary">计算</button>
            </div>
        </div>
    </div>
</body>
</html>

from django.conf.urls import url
from django.contrib import admin
from app01 import views

urlpatterns = [
    url(r'^index/', views.index, name='user_index'),
    url(r'^compute/', views.compute, name='user_compute'),  # 用来处理用户的计算请求
]

from django.shortcuts import render, HttpResponse


# Create your views here.
def index(request):
    return render(request, 'index.html')  # 用户访问 http://127.0.0.1:8000/user/index/ 直接给他返回 index.html 这个页面


from django.http import JsonResponse  # 下面发json数据要用到


def compute(request):
    # 判读是否是 ajax 请求
    if request.is_ajax():
        # 定义一个空的字典，用来存放一会儿的返回信息
        back_dic = {

        }
        # 前端 ajax采用的是 post 请求，所以这里这样获取数据
        num1 = request.POST.get('num1')
        num2 = request.POST.get('num2')
        # 判断数据格式是否正确
        if num1.isdigit() and num2.isdigit():
            try:
                res = int(num1) + int(num2)
                back_dic['status'] = 200
                back_dic['res'] = res
            except Exception as e:
                print(e)
                back_dic['status'] = 100
                back_dic['err'] = e
        # 格式不正确返回错误信息
        else:
            back_dic['status'] = 100
            back_dic['err'] = '请输入合法数字！'
        # 用 JsonResponse 将字典打包成 json 格式数据返回给前端
        #   json 格式的数据前端可以直接解析成 前端的自定义对象
        return JsonResponse(back_dic)

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>测试页</title>
    {#    为了测试方便，这里就用网上的 jquery 了，用 CDN 的形式引入#}
    <script src="https://cdn.bootcss.com/jquery/3.4.1/jquery.min.js"></script>
    {#    下面练习一下静态资源路径动态解析，并且 boostrap 放在本地会有语法提示，可以加快开发效率#}
    {% load static %}
    <link rel="stylesheet" href="{% static 'bootstrap-3.3.7-dist/css/bootstrap.min.css' %}">
    <script src="{% static 'bootstrap-3.3.7-dist/js/bootstrap.min.js' %}"></script>
</head>
<body>
{#随便搭一个页面#}
<div class="container">
    <div class="row">
        <div class="text-center">
            <input type="text" id="num1"> +
            <input type="text" id="num2"> =
            <input type="text" id="res">
            <button class="btn btn-primary" id="button1">计算</button>
        </div>
    </div>
</div>
<script>
    {#    1.为了能够获取到对应输入框和按钮以及输入框的值，我们需要先给他们加上 id #}
    $('#button1').click(function (e) {  {# 2.给我们的 计算 按钮绑定点击事件，点击时用 ajax 发送请求，然后后端计算并返回数值，放在 id 为 res 的 input 里 #}
        $.ajax({  {# 3.Jquery 的 ajax，需要下面几个参数，记得写上（Ajax 的括号内是一个大括号，然后再写的参数） #}
            url: '{% url "user_compute" %}', {# 4.写 ajax 发送请求的地址，这里用的 url 反向解析 #}
            type: 'post', {# 5.采用 post 请求发送数据 #}
            data: {  {# 6.把要发送过去的数据打包 #}
                'num1': $('#num1').val(),  {# 7.获取到 id 为 num1 的标签的 value值 #}
                'num2': $('#num2').val()
            },
            success: function (data) {  {# 8.请求成功的回调函数 #}
                if (data.status == 200) {  {# 9.后端手动设置的码， 200 表示数据类型没问题 #}
                    $('#res').val(data.res);  {# 数据没问题就打印出来 #}
                } else {  {# 10.码不是 200 表示数据类型有误等，弹窗提示错误信息 #}
                    alert(data.err);
                }
            }
        })
    })
</script>
</body>
</html>

$('#b1').on('click',function () {
    // 点击按钮 朝后端发送post请求
    $.ajax({
        url: '',  // 控制发送给谁 不写就是朝当前地址提交
        type: 'post',  // 发送方式是post请求
        data: JSON.stringify({'username': 'jason', 'password': 123}),  // 发送的数据
        contentType: 'application/json',  // 告诉后端你这次的数据是json格式

        success: function (data) {  // data形参用来接收异步提交的结果
            // 将后端计算好的结果 通过DOM操作 渲染到第三个input矿中
            $('#i3').val(data)
        }
    })
})

from django.shortcuts import render,HttpResponse
from app01 import models
# Create your views here.
def index(request):
    # 验证前后端传输数据的编码格式
    if request.method == 'POST':
        print(request.body)
        # 后端 需要手动去request.body中获取json格式数据  自己处理
        json_str = request.body
        import json
        s = json_str.decode('utf-8')
        ral_d = json.loads(s)
        print(ral_d, type(ral_d))
        return HttpResponse('OK')
    return render(request, 'index.html')

 // ajax传输文件
$('#b1').on('click',function () {
    // ajax 传输文件 建议使用内置对象 formdata
    var formData = new FormData();  // 既可以传普通的键值对 也可以传文件
    // 添加普通键值（后续可以改成 for 循环填充）
    formData.append('username','jason');
    formData.append('password','123');
    formData.append('my_file',$('#d1')[0].files[0]);
    $.ajax({
        url:'',  // 控制发送给谁 不写就是朝当前地址提交
        type:'post',  // 发送方式是post请求
        data:formData, // 发送的数据

        // ajax发送文件需要指定两个额外的参数
        processData:false,  // 告诉前端不要处理数据
        contentType:false,  // 不适用任何编码  因为formdata对象自身自带编码 django后端也能够识别formdata对象

        success:function (data) {  // data形参用来接收异步提交的结果
            {# alert(data) #}
            // 将后端计算好的结果 通过DOM操作 渲染到第三个input矿中
            $('#i3').val(data)
        }

    })
})

from django.core import serializers  # django自带的一个小型的序列化工具
from app01 import models
import json


def reg(request):
    user_list = models.User.objects.all()
    # 将所有的数据都组织成一个符合 json 格式的一个个的字典
    # user_l = []
    # for user_obj in user_list:
    #     user_l.append(
    #         json.dumps({
    #             'username': user_obj.username,
    #             'age': user_obj.age,
    #             'gender': user_obj.get_gender_display()
    #         })
    #     )
    res = serializers.serialize('json', user_list)  # 指定序列化格式为 json
    return render(request, 'index.html', locals())

[{
    "model": "app01.user",
    "pk": 1,
    "fields": {
        "username": "jason",
        "age": 18,
        "gender": 1
    }
}, {
    "model": "app01.user",
    "pk": 2,
    "fields": {
        "username": "tank",
        "age": 24,
        "gender": 3
    }
}, {
    "model": "app01.user",
    "pk": 3,
    "fields": {
        "username": "egon",
        "age": 73,
        "gender": 2
    }
}, {
    "model": "app01.user",
    "pk": 7,
    "fields": {
        "username": "kevin",
        "age": 29,
        "gender": 4
    }
}]

from app01 import models
from django.core import serializers  # django 自带的一个小型的序列化工具

def reg(request):
    user_list = models.User.objects.all()
    res = serializers.serialize('json', user_list)
    return render(request, 'index.html', locals())

<style>
    div.sweet-alert h2{
        padding-top: 10px;
    }
</style>

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script src="https://cdn.bootcss.com/jquery/3.4.1/jquery.min.js"></script>
    {% load static %}
    <link rel="stylesheet" href="{% static 'bootstrap-3.3.7-dist/css/bootstrap.min.css' %}">
    <link rel="stylesheet" href="{% static 'dist/sweetalert.css' %}">
    <script src="{% static 'bootstrap-3.3.7-dist/js/bootstrap.min.js' %}"></script>
    <script src="{% static 'dist/sweetalert.min.js' %}"></script>

    <style>
        div.sweet-alert h2{
            padding-top: 10px;
        }
    </style>
</head>
<body>
<div class="container">
    <div class="row">
        <div class="col-md-8 col-md-offset-2">
            <h2 class="text-center">数据展示</h2>
            <table class="table-striped table table-hover table-bordered">
                <thead>
                    <tr>
                        <th>序号</th>
                        <th>主键</th>
                        <th>用户名</th>
                        <th>年龄</th>
                        <th>性别</th>
                        <th>操作</th>
                    </tr>
                </thead>
                <tbody>
                    {% for user in user_list %}
                        <tr>
                            <td>{{ forloop.counter }}</td>
                            <td>{{ user.pk }}</td>
                            <td>{{ user.username }}</td>
                            <td>{{ user.age }}</td>
                            <td>{{ user.get_gender_display }}</td>
                            <td>
                                <button class="btn btn-primary btn-sm">编辑</button>
                                <button class="btn btn-danger btn-sm del" user_id="{{ user.pk }}">删除</button>
                            </td>
                        </tr>
                    {% endfor %}
                </tbody>
            </table>
        </div>
    </div>
</div>
<script>
    $('.del').click(function () {
        // 获取当前标签对象
        var $btnEle = $(this);

        swal({
          title: "你确定要删吗?",
          text: "你要是删了,你就准备跑路吧!",
          type: "warning",
          showCancelButton: true,
          confirmButtonClass: "btn-danger",
          confirmButtonText: "是的,老子就要删!",
          cancelButtonText: "算了,算了!",
          closeOnConfirm: false,
          showLoaderOnConfirm: true
        },
        function(){
            // 朝后端发送ajax请求
            $.ajax({
                url:'',
                type:'post',
                data:{'delete_id':$btnEle.attr('user_id')},
                success:function (data) {  // 后端发字典过来 前端不需要你手动转 会自动帮你转换成js自定义对象
                    if (data.code == 100){
                        {#window.location.href = '';  // 不写就是条到当前页面#}
                        // 通过DOM操作 实时改变页面
                        // 将被点击的删除按钮所在的那一行直接从DOM树中删掉
                        $btnEle.parent().parent().remove();
                        swal("删掉了!", "赶紧回去收拾行李吧,准备跑路!", "success");
                    }else{
                        swal('发生了未知的错误','估计是有bug了','info')
                    }
                }
            });

        });
    })
</script>

</body>
</html>

from django.http import JsonResponse
import time
def userlist(request):
    if request.is_ajax():
        time.sleep(3)
        """
        一般情况下 针对ajax请求 后端通常都是返回一个字典
        """
        back_dic = {'code':100,'msg':''}
        # 直接获取用户想删除的数据的id值
        delete_id = request.POST.get('delete_id')
        # 直接利用queryset方法 批量删除
        models.User.objects.filter(pk=delete_id).delete()
        # 要给前端ajax返回一个消息(字典)
        back_dic['msg'] = '真的删除了!'
        return JsonResponse(back_dic)


    user_list = models.User.objects.all()
    return render(request,'userlist.html',locals())

l = []

for i in range(10000):
    l.append(models.Book(title=f'书籍{i}'))
models.Book.objects.bulk_create()  # 批量插入数据

"""
per_page_num = 10

current_page                start_page                  end_page
    1                           0                           10
    2                           10                          20
    3                           20                          30  
    4                           30                          40

per_page_num = 5

current_page                start_page                  end_page
    1                           0                           5
    2                           5                           10
    3                           10                          15  
    4                           15                          20

start_page = (current_page - 1) * per_page_num
end_page =  current_page* per_page_num


10000
10

1000


10001
10

1001

"""

class Pagination(object):
    def __init__(self, current_page, all_count, per_page_num=2, pager_count=11):
        """
        封装分页相关数据
        :param current_page: 当前页
        :param all_count:    数据库中的数据总条数
        :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

        用法:
        queryset = model.objects.all()
        page_obj = Pagination(current_page,all_count)
        page_data = queryset[page_obj.start:page_obj.end]
        获取数据用page_data而不再使用原始的queryset
        获取前端分页样式用page_obj.page_html
        """
        try:
            current_page = int(current_page)
        except Exception as e:
            current_page = 1

        if current_page < 1:
            current_page = 1

        self.current_page = current_page

        self.all_count = all_count
        self.per_page_num = per_page_num

        # 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)

    @property
    def start(self):
        return (self.current_page - 1) * self.per_page_num

    @property
    def end(self):
        return self.current_page * 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 <= 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 + self.pager_count_half) > self.all_pager:
                    pager_end = self.all_pager + 1
                    pager_start = self.all_pager - self.pager_count + 1
                else:
                    pager_start = self.current_page - self.pager_count_half
                    pager_end = self.current_page + self.pager_count_half + 1

        page_html_list = []
        # 添加前面的nav和ul标签
        page_html_list.append('''
                    <nav aria-label='Page navigation>'
                    <ul class='pagination'>
                ''')
        first_page = '<li><a href="?page=%s">首页</a></li>' % (1)
        page_html_list.append(first_page)

        if self.current_page <= 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 - 1,)

        page_html_list.append(prev_page)

        for i in range(pager_start, pager_end):
            if i == self.current_page:
                temp = '<li class="active"><a href="?page=%s">%s</a></li>' % (i, i,)
            else:
                temp = '<li><a href="?page=%s">%s</a></li>' % (i, i,)
            page_html_list.append(temp)

        if self.current_page >= 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 + 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)
        # 尾部添加标签
        page_html_list.append('''
                                           </nav>
                                           </ul>
                                       ''')
        return ''.join(page_html_list)

# ...其他代码
from app01.utils.mypage import Pagination
def book(request):
    # 使用封装好的自定义分页器
    book_list = models.Book.objects.all()
    current_page = request.GET.get("page", 1)
    all_count = book_list.count()
    page_obj = Pagination(current_page=current_page, all_count=all_count, per_page_num=10)
    page_queryset = book_list[page_obj.start:page_obj.end]

    return render(request, 'booklist.html', locals())
# ...其他代码

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script src="https://cdn.bootcss.com/jquery/3.4.1/jquery.min.js"></script>
    {% load static %}
    <link rel="stylesheet" href="{% static 'bootstrap-3.3.7-dist/css/bootstrap.min.css' %}">
    <link rel="stylesheet" href="{% static 'dist/sweetalert.css' %}">
    <script src="{% static 'bootstrap-3.3.7-dist/js/bootstrap.min.js' %}"></script>
    <script src="{% static 'dist/sweetalert.min.js' %}"></script>
</head>
<body>
<div class="container">
    <div class="row">
        <div class="col-md-8 col-md-offset-2">
            {% for book in page_queryset %}
                <p>{{ book.title }}</p>
            {% endfor %}
            {{ page_obj.page_html|safe }}  {# 支持转义，让 html 格式的字符串可以渲染出来 #}
        </div>
    </div>
</div>
</body>
</html>