高级应用

高级应用

一、Admin后台管理

1、概述

什么是admin？

admin是后台可视化界面管理系统 方便模型的操作与维护

2、配置

• settings.py
  INSTALLED_APPS = [
  'django.contrib.admin',
  ]
  汉化
  LANGUAGE_CODE = 'zh-Hans'

  TIME_ZONE = 'Asia/Shanghai'
  

• 创建用户进行访问
  python manage.py createsuperuser
  依次输入用户名 邮箱 密码

• 路由访问
  127.0.0.1:8000/admin/

3、配置后台

班级与学生模型类

• models.py
  from django.db import models

  # 创建班级模型
  class Grade(models.Model):
      gname = models.CharField(max_length=10, default='python36')
      gnum = models.SmallIntegerField(default=30)
      gboynum = models.SmallIntegerField(default=15)
      ggirlnum = models.SmallIntegerField(default=15)
      def __str__(self):
          return self.gname
      class Meta:
          db_table = 'grade'
  
  
  # 创建学生模型
  class Student(models.Model):
      sname = models.CharField(max_length=10, default='张三')
      sage = models.SmallIntegerField(default=18)
      ssex = models.BooleanField(default=True)
      # 一对多外键关系 从表随着主表而删除
      # sgrade = models.ForeignKey(Grade, on_delete=models.CASCADE)
      # sgrade = models.ForeignKey(Grade, on_delete=models.SET_NULL, null=True)
      # sgrade = models.ForeignKey(Grade, on_delete=models.PROTECT)
      sgrade = models.ForeignKey(Grade, on_delete=models.SET_DEFAULT, default=1)
  
      def __str__(self):
          return self.sname
      class Meta:
          db_table = 'student'
  

• 设置为中文显示(字段在后台进行中文显示)
  class Grade(models.Model):
  ...
  ggirlnum = models.SmallIntegerField(default=15, verbose_name='女生人数')
  class Meta:
  db_table = 'grade'
  verbose_name = '班级'
  class Student(models.Model):
  ...

• admin.py
  from django.contrib import admin
  from App.models import Grade, Student

  # class StudentInfo(admin.StackedInline):  # 竖着
  class StudentInfo(admin.TabularInline):  # 横着
      model = Student
      extra = 2
  
  @admin.register(Grade)
  class GradeAdmin(admin.ModelAdmin):
      inlines = [StudentInfo]
      # 字段显示
      list_display = ['pk', 'gname', 'gnum', 'gboynum', 'ggirlnum']
      # 过滤字段
      list_filter = ['gname']
      # 搜索字段
      search_fields = ['gname']
      # 分页
      list_per_page = 5  # 每页显示五条数据
      # 更改添加修改样式
      # fields = ['gname', 'gnum', 'gboynum', 'ggirlnum']
      # 添加修改分组(fieldsets和fields不能同时存在)
      fieldsets = [
          ('组一', {'fields':['gboynum', 'ggirlnum']}),
          ('组二', {'fields':['gname', 'gnum']})
      ]
  
  
  
  @admin.register(Student)
  class StudentAdmin(admin.ModelAdmin):
      def show_sex(self):
          if self.ssex:
              return '男'
          else:
              return '女'
  
      show_sex.short_description = '性别'
      list_display = ['pk', 'sname', 'sage', show_sex, 'sgrade']
  
  
  # Register your models here.
  # admin.site.register(Grade, GradeAdmin)
  # admin.site.register(Student, StudentAdmin)
  

二、邮件发送

https://docs.djangoproject.com/zh-hans/3.2/topics/email/#django.core.mail.send_mass_mail

1、配置

基础阶段里面的邮箱配置

2、发送邮件

def test_send_mail(req):
    from django.core.mail import send_mail
    send_mail(
        '主体',
        '邮件内容',
        settings.EMAIL_HOST_USER,
        ['793390457@qq.com'],
        fail_silently=False,
    )
    return HttpResponse('发送邮件')

3、群发

from django.core.mail import send_mass_mail
message1 = ('Subject here', 'Here is the message', 'from@example.com', ['first@example.com', 'other@example.com'])
message2 = ('Another Subject', 'Here is another message', 'from@example.com', ['second@test.com'])
send_mass_mail((message1, message2), fail_silently=False)

send_mass_mail（）和send_mail（）之间的主要区别在于，send_mail（）每次执行时都会打开到邮件服务器的连接，而send_mass_mail（）对其所有邮件使用单个连接。这使得send_mass_mail（）的效率略微提高。

4、使用文本和html发送

from django.core.mail import EmailMultiAlternatives

subject, from_email, to = 'hello', 'from@example.com', 'to@example.com'
text_content = 'This is an important message.'
html_content = '<p>This is an <strong>important</strong> message.</p>'
msg = EmailMultiAlternatives(subject, text_content, from_email, [to])
msg.attach_alternative(html_content, "text/html")
msg.send()

5、使用html发送

from django.core.mail import send_mass_mail, EmailMessage
msg = EmailMessage('主体', '<b>邮件内容</b>', settings.EMAIL_HOST_USER, ['793390457@qq.com','948807313@qq.com'])
    msg.content_subtype = "html"  # Main content is now text/html
    msg.send()

三、分页

1、Paginator对象

• 创建对象
  Paginator()
• 属性
  count 对象总数
  num_pages 页面总数
  page_range 页码列表
• 方法
  page(num)

2、page对象

通过Paginator的方法page 得到page对象

• 属性
  object_list 当前页上所有数据
  number 当前页的页码值
  paginator 获取paginator 对象
• 方法
  has_next 是否有下一页
  has_previous 是否有上一页
  next_page_num 返回下一页页码
  previous_page_num 返回上一页页码

3、实例

• views.py
  def index(req):
  nowPage = req.GET.get('page',1)
  stu = Student.objects.all()
  p = Paginator(stu, 2)
  # print(p)

      # 通过页码获取当前页的对象
      try:
          # 判断页码是否合法
          if int(nowPage) >= int(p.num_pages):
              nowPage = p.num_pages
          page = p.page(nowPage)
      except:
          page = p.page(p.num_pages)
  
      return render(req, 'index.html', {'page': page})
  

• index.html
  
  
  
  
  
  
  
  
  首页

  <ol>
      {% for s in page.object_list   %}
          <li>{{ s.sname }}</li>
      {% endfor %}
  </ol>
  
  <nav aria-label="Page navigation">
    <ul class="pagination pagination-lg">
      <li>
        <a {% if page.has_previous %}href="{% url 'App:index' %}?page={{ page.previous_page_number }}"{% endif %} aria-label="Previous">
          <span aria-hidden="true">&laquo;</span>
        </a>
      </li>
        {% for index in page.paginator.page_range %}
            <li {% if index == page.number %}class="active"{% endif %}><a href="{% url 'App:index' %}?page={{ index }}">{{ index }}</a></li>
        {% endfor %}
  
  {#    <li><a href="#">2</a></li>#}
      <li>
        <a {% if page.has_next %}href="{% url 'App:index' %}?page={{ page.next_page_number }}"{% endif %} aria-label="Next">
          <span aria-hidden="true">&raquo;</span>
        </a>
      </li>
    </ul>
  </nav>
  </body>
  </html>
  

四、中间件

1、说明

中间件就是在请求与响应过程中 进行安全验证的功能 每个中间件组件都会负责做一些特定的功能

2、本质

python类

3、使用场景

• 白名单、黑名单
• url访问过滤
• 缓存

浏览器->中间件->url路由地址分发->中间件->视图函数->中间件->响应->

4、方法

• process_request(self, req)
  在执行视图之前被调用(分配url匹配视图) 每个请求都会被调用 返回None或者response对象
• process_view(self, req, view_func, view_args, view_kwargs)
  调用视图之前进行调用 每个表请求都会调用 返回None或者response对象
• process_response(self, req, response)
  所有响应在返回浏览器之前都会被调用 返回response
• process_exception(self, req, exception)
  当视图抛出异常时进行调用

5、自定义中间件

• App同级创建middleware文件夹
  App/
  middleware/
  myMiddly.py

• myMiddly.py中创建MyMiddle类
  from django.utils.deprecation import MiddlewareMixin
  from django.shortcuts import HttpResponse, redirect

  class MyMiddle(MiddlewareMixin):
      def process_request(self, req):
          print(req.path)
          print(req.method)
          print(req.META['REMOTE_ADDR'])
          # if req.META['REMOTE_ADDR'] == '127.0.0.1':
          #     return HttpResponse('您被拦截了')
  
      def process_exception(self, req, exception):
          print(exception)
          return redirect('/a/')
  

• settings.py
  middleware中添加
  'middleware.myMiddle.MyMiddle',