一、第十天作业
使用中间件完成一个随机抽奖的场景，每次发出请求后，产生一个1~100的随机数， 如果随机数的值大于90，则跳转到中奖页面，显示“恭喜，您中奖了”，否则返回给 客户端一个文本“抱歉，本次未中奖”。
1.1代码演示
1、mymiddleware
#mymiddleware/mymiddleware.py
from django.http import HttpResponse
from django.utils.deprecation import MiddlewareMixin
import random
class PrizeMiddleware(MiddlewareMixin):
def process_request(self,request):
number = random.randint(1,100)
print("number=",number)
if number<=90:
return HttpResponse("<h3 style='color:red'>抱歉，本次未中奖</h3>")
request.prize_number = number #动态添加一个属性
2、views
from django.shortcuts import render def prize_view(request): return render(request,'homeworkapp/congratulation.html')
3、templates
<!homeworkapp/congratulation.html>
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>中奖页面</title>
</head>
<body>
<h3>恭喜，您中奖了,中奖数字为：{{ request.prize_number }}</h3>
</body>
</html>
4、urls
#子路由
from django.urls import path
from homeworkapp.views import prize_view
urlpatterns = [
path('prize/',prize_view),
]
#总路由
from django.contrib import admin
from django.urls import path,include
urlpatterns = [
path('admin/', admin.site.urls),
path('homeworkapp/',include('homeworkapp.urls')),
二、Django类视图
类视图可以封装处理不同请求的方法，自定义类视图需要继承 "from django.views import View"类，在类中实现自己要处理请求的方法， eg:get(self,request)、post(self,request)
由于View类有很多子类，所以也可以继承View的某些子类实现类视图。例如： 继承TemplateView类，可以通过template_name类属性指定模板； 继承RedirectView类，可以通过pattern_name指定重定向的路径(namespace:name)。
2.1 代码演示
1、views
from django.http import HttpResponse, JsonResponse
from django.shortcuts import render, redirect
from django.urls import reverse
from django.views import View
from django.views.generic import TemplateView, RedirectView
from viewapp.forms import RegForm
# def go_welcome(request,regname):
# return render(request,'viewapp/welcome.html',locals())
class HelloView(View):
def get(self,request):
return HttpResponse("<h3 style='color:red'>欢迎学习类视图~~~</h3>")
def post(self,request):
username = request.POST["username"]
password = request.POST["pwd"]
return JsonResponse({"yourname":username,"yourpwd":password})
class RegisterView(View):
def get(self,request):
regform = RegForm()
return render(request,'viewapp/register.html',locals())
def post(self,request):
regform = RegForm(request.POST) # 接收表单数据，并封装到RegForm对象中
if regform.is_valid():
regname = regform.cleaned_data["regname"]
regpwd = regform.cleaned_data["regpwd"]
print("模拟插入数据库，注册用户名是：",regname,"；注册密码是：",regpwd)
return redirect(reverse("viewapp:mytemplate",args=(regname,)))
else:
return HttpResponse("<h3 style='color:red'>表单数据没有通过验证！</h3>")
class MyTemplateView(TemplateView):
template_name = "viewapp/welcome.html" #指定模板路径
def get(self,request,regname):
print("get接收到参数了：",regname)
return render(request, 'viewapp/welcome.html', locals())
class MyRedirectView(RedirectView):
pattern_name = "viewapp:reg" # 指定重定向路径,pattern_name保存的是重定向路径
2、forms.py
from django import forms class RegForm(forms.Form): regname = forms.CharField(label="注册用户名",max_length=10) regpwd = forms.CharField(label="注册密码",max_length=8,widget=forms.PasswordInput())
3、templates
<!register.html>
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>注册页面</title>
</head>
<body>
<form action="{% url 'viewapp:reg' %}" method="post">
{% csrf_token %}
{{ regform.as_p }}
<input type="submit" value="注册"/>
</form>
</body>
</html>
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>欢迎页面</title>
</head>
<body>
<h3>欢迎，{{ regname }},您已经注册成功！</h3>
</body>
</html>
4、urls
#子路由
from django.urls import path
from viewapp.views import *
app_name = "viewapp"
urlpatterns = [
# path('welcome/<regname>/',go_welcome,name="welcome"),
path('hello/',HelloView.as_view(),name="hello"),
path('register/',RegisterView.as_view(),name="reg"),
path('mytemplate/<regname>/',MyTemplateView.as_view(),name="mytemplate"),
path('yourredirect/',MyRedirectView.as_view(),name="yourredirect"),
]
#总路由
path('viewapp/',include('viewapp.urls',namespace="viewapp")),
三、多级评论案例
模型自关联+递归 详细见代码
1、views
from django.db import models
class Article(models.Model):
title = models.CharField(max_length=20,verbose_name="文章标题")
content = models.TextField(verbose_name="文章内容")
publishdate = models.DateField(verbose_name="发表日期")
def __str__(self):
return self.title
class Meta:
db_table = "articles"
verbose_name = "文章模型"
verbose_name_plural = verbose_name
class Comment(models.Model):
content = models.CharField(max_length=100,verbose_name="评论内容")
article = models.ForeignKey(Article,on_delete=models.CASCADE,verbose_name="评论的文章")
parent_comment = models.ForeignKey('self',on_delete=models.CASCADE,null=True,blank=True,verbose_name="父级评论")
comment_date = models.DateField(verbose_name="评论日期")
def __str__(self):
return self.content
class Meta:
db_table = "comments"
verbose_name = "评论模型"
verbose_name_plural = verbose_name
ordering = ["comment_date"] # 按照评论时间排序
2、comment/comment_util.py
def create_comment_tree(article):
comments = article.comment_set.all() # 将文章对应的所有评论查询出来
comment_tree = {}
for comment in comments: # 遍历该文章的所有评论
if comment.parent_comment is None: # 如果该评论没有父评论（针对文章本身的评论）
comment_tree[str(comment)] = {}
else:
find_parent_comment(comment,comment_tree)
return comment_tree
def find_parent_comment(comment,comment_tree):
for p,v in comment_tree.items():
if p == str(comment.parent_comment): # 判断当前遍历的评论对象是否为comment的父评论对象
comment_tree[str(p)][str(comment)] = {} # 关联父评论对象与子评论对象
break
else:
find_parent_comment(comment,comment_tree[p])
3、views
from django.http import JsonResponse, HttpResponse
from django.shortcuts import render
from commentapp.models import Article
from commentapp.comment.comment_util import create_comment_tree
def find_comments(request,article_id):
try:
article_id = int(article_id)
except:
return HttpResponse("<h3 style='color:red'>文章编号错误！</h3>")
article = Article.objects.get(id=article_id)
comment_tree = create_comment_tree(article)
print(comment_tree)
return JsonResponse(comment_tree)
4、admin.py
from django.contrib import admin from commentapp.models import * admin.site.register([Article,Comment])
5、urls
#子路由
from django.urls import path
from commentapp.views import find_comments
urlpatterns = [
path('comments/<article_id>/',find_comments),
]
#总路由
path('commentapp/',include('commentapp.urls')),