课程展示

课程展示

#urls.py
from django.conf.urls import url,include
from django.contrib import admin
from app01.view.course import Courseview,CourseDetailview

from rest_framework import routers
router=routers.DefaultRouter()
router.register("courses",Courseview)  #课程类
router.register("coursedetail",CourseDetailview)  #课程详情类

urlpatterns = [
    url(r'^admin/', admin.site.urls),
    url("^", include(router.urls)),   #使用url注册器制作
]

#app01/view/course.py  #写一个文件夹view，删除views.py，专门存放视图函数
from rest_framework.views import APIView
from rest_framework.viewsets import ModelViewSet
from ..models import *
from app01.utils.serializer import *

class Courseview(ModelViewSet):
    queryset = Course.objects.all()
    serializer_class = CourseSerializers 

#app01/view/coursedetail.py

from rest_framework.views import APIView
from rest_framework.viewsets import ModelViewSet
from ..models import *
from app01.utils.serializer import *


class CourseDetailview(ModelViewSet):
    queryset = CourseDetail.objects.all()
    serializer_class = CourseDetailSerlizers

#app01/utils/serializer.py   #专门存放序列化组件

from rest_framework import serializers
from ..models import *

class CourseSerializers(serializers.ModelSerializer):

    level=serializers.SerializerMethodField()   #前端需要关联表中的字段，而不是id值
    def get_level(self,obj):
        return obj.get_level_display()


    class Meta:
        model=Course
        fields="__all__"



class CourseDetailSerlizers(serializers.ModelSerializer):

    course_name=serializers.CharField(source="course.name")
    price_policy_list=serializers.SerializerMethodField()
    recommend_courses=serializers.SerializerMethodField()
    teachers=serializers.SerializerMethodField()


    def get_recommend_courses(self,obj):  #将推荐课程，里的具体内容传给前端页面，而不是仅传id值

        temp=[]
        for course in obj.recommend_courses.all():
            temp.append({
                "pk":course.pk,
                "name":course.name
            })

        return temp

    #比如写个访问老师信息时：（参考本段红色代码，还有postman红色代码即可），如果不这么写，就会返回老师ID值。
    def get_teachers(self,obj):

        temp=[]
        for teacher in obj.teachers.all():
            temp.append({
                "pk":teacher.pk,
                "name":teacher.name
            })

        return temp

    def get_price_policy_list(self,obj):
        temp=[]
        for price_obj in obj.course.price_policy.all():
            temp.append({
                "pk":price_obj.pk,
                "price":price_obj.price,
                "valid_period":price_obj.valid_period,
                "valid_period_text":price_obj.get_valid_period_display(),
            })

        return temp

    class Meta:
        model=CourseDetail
        fields="__all__"

访问http://127.0.0.1:8000/coursedetail/时，效果

[
    {
        "id": 1,
        "course_name": "python全栈",
        "price_policy_list": [
            {
                "pk": 1,
                "price": 100,
                "valid_period": 7,
                "valid_period_text": "1周"
            },
            {
                "pk": 2,
                "price": 200,
                "valid_period": 14,
                "valid_period_text": "2周"
            },
            {
                "pk": 3,
                "price": 300,
                "valid_period": 180,
                "valid_period_text": "6个月"
            }
        ],
        "recommend_courses": [
            {
                "pk": 1,
                "name": "python全栈"
            }
        ],
        "teachers": [
            {
                "pk": 1,
                "name": "alex"
            }
        ],
        "hours": 200,
        "course_slogan": "python,让世界上的程序员不再秃顶",
        "course": 1
    },
    {
        "id": 2,
        "course_name": "Linux云计算运维",
        "price_policy_list": [
            {
                "pk": 4,
                "price": 0,
                "valid_period": 7,
                "valid_period_text": "1周"
            },
            {
                "pk": 5,
                "price": 100,
                "valid_period": 14,
                "valid_period_text": "2周"
            },
            {
                "pk": 6,
                "price": 300,
                "valid_period": 180,
                "valid_period_text": "6个月"
            }
        ],
        "recommend_courses": [
            {
                "pk": 1,
                "name": "python全栈"
            }
        ],
        "teachers": [
            {
                "pk": 2,
                "name": "egon"
            }
        ],
        "hours": 400,
        "course_slogan": "linux,每个程序员必会的东东",
        "course": 2
    },
    {
        "id": 3,
        "course_name": "算法入门",
        "price_policy_list": [
            {
                "pk": 7,
                "price": 500,
                "valid_period": 180,
                "valid_period_text": "6个月"
            }
        ],
        "recommend_courses": [
            {
                "pk": 1,
                "name": "python全栈"
            }
        ],
        "teachers": [
            {
                "pk": 4,
                "name": "Doctor Zhao"
            }
        ],
        "hours": 30,
        "course_slogan": "算法是这个世界的砖瓦",
        "course": 3
    }
]

遇见的问题

跨域

需要在settings.py中注册中间件
#utils/middlewares.py

from django.utils.deprecation import MiddlewareMixin

class CoreMiddleWares(MiddlewareMixin):
    def process_response(self,request,response):   #由于是简单请求 post
        response["Access-Control-Allow-Origin"]="*"
        return response