使用Django Rest framework搭建Blog

在前面的Blog例子中我們使用的是GraphQL, 雖然GraphQL的使用處於上升趨勢,但是Rest API還是使用的更廣泛一些.

所以還是決定回到傳統的rest api framework上來, Django rest framework的官網上給了一個很好用的QuickStart, 我參考Quick Start將前面的Blog的例子用DRF(Django Rest Framework)重新構築一遍.

搭建Blog的rest api server

創建Blog Django project

安裝DRF(Django Rest Framework)

pip install djangorestframework

創建Blog Project

django-admin startproject drf_backend
cd drf_backend
django-admin startapp blog
cd ..

python manage.py migrate #創建預設的sqlite資料庫
python manage.py createsuperuser  #創建super user
python manage.py runserver  #啟動服務

上述操作後可以進入http://127.0.0.1:8000/admin 查看服務

創建Blog Models

參考前面Blog的代碼在models.py加入 Post, Tag, Profile的Model代碼

在admin.py中加入預設的管理頁面, 

blog/models.py

from django.db import models
from django.conf import settings

# Create your models here.

class Profile(models.Model):
    user = models.OneToOneField(
        settings.AUTH_USER_MODEL,
        on_delete=models.PROTECT,
    )
    website = models.URLField(blank=True)
    bio = models.CharField(max_length=240, blank=True)

    def __str__(self):
        return self.user.get_username()

class Tag(models.Model):
    name = models.CharField(max_length=50, unique=True)

    def __str__(self):
        return self.name

class Post(models.Model):
    class Meta:
        ordering = ["-publish_date"]

    title = models.CharField(max_length=255, unique=True)
    subtitle = models.CharField(max_length=255, blank=True)
    slug = models.SlugField(max_length=255, unique=True)
    body = models.TextField()
    meta_description = models.CharField(max_length=150, blank=True)
    date_created = models.DateTimeField(auto_now_add=True)
    date_modified = models.DateTimeField(auto_now=True)
    publish_date = models.DateTimeField(blank=True, null=True)
    published = models.BooleanField(default=False)

    author = models.ForeignKey(Profile, on_delete=models.PROTECT)
    tags = models.ManyToManyField(Tag, blank=True)   

blog/admin.py

from django.contrib import admin
from blog.models import Profile, Post, Tag

# Register your models here.
@admin.register(Profile)
class ProfileAdmin(admin.ModelAdmin):
    model = Profile

@admin.register(Tag)
class TagAdmin(admin.ModelAdmin):
    model = Tag

@admin.register(Post)
class PostAdmin(admin.ModelAdmin):
    model = Post

    list_display = (
        "id",
        "title",
        "subtitle",
        "slug",
        "publish_date",
        "published",
    )
    list_filter = (
        "published",
        "publish_date",
    )
    list_editable = (
        "title",
        "subtitle",
        "slug",
        "publish_date",
        "published",
    )
    search_fields = (
        "title",
        "subtitle",
        "slug",
        "body",
    )
    prepopulated_fields = {
        "slug": (
            "title",
            "subtitle",
        )
    }
    date_hierarchy = "publish_date"
    save_on_top = True

構造資料庫

python manage.py makemigrations
python manage.py migrate

數據Serializers

創建 blog/serializers.py, 這裡我們使用HyperlinkedModelSerializer 類, 也可以使用ModelSerializer. 這兩者的區別在於HyperLinkedModelSerializer將id直接變成url形式,這樣可以不用在代碼中再構造url.

from blog.models import Post,Tag,Profile
from django.contrib.auth.models import User
from rest_framework import serializers

class PostSerializer(serializers.HyperlinkedModelSerializer):
    class Meta:
        model = Post
        fields = ['url','title','subtitle','slug','body','meta_description','date_created','publish_date','published','author','tags']

class TagSerializer(serializers.HyperlinkedModelSerializer):
    class Meta:
        model = Tag
        fields = ['url','name']

class ProfileSerializer(serializers.HyperlinkedModelSerializer):
    class Meta:
        model = Profile
        fields = ['url','profile_pic','bio','user']

class UserSerializer(serializers.HyperlinkedModelSerializer):
    class Meta:
        model = User
        fields = ['url','username','email','password']

Views

對應的rest api的請求,我們在blog/views.py中加入相關的處理 

from django.shortcuts import render
from django.contrib.auth.models import User
from blog.models import Post,Tag,Profile
from rest_framework import  viewsets,permissions
from blog.serializers import PostSerializer,TagSerializer,ProfileSerializer

class PostViewSet(viewsets.ModelViewSet):
    queryset = Post.objects.all().order_by('publish_date')
    serializer_class = PostSerializer
#    permission_classes = [permissions.IsAuthenticated]


class TagViewSet(viewsets.ModelViewSet):
    queryset = Tag.objects.all()
    serializer_class = TagSerializer


class ProfileViewSet(viewsets.ModelViewSet):
    queryset = Profile.objects.all()
    serializer_class = ProfileSerializer

*註意我們這裡先不使用permission_classes,如果使用的話,在瀏覽器上就必須Login才能取得對應的數據

配置URL

在drf_backend/urls.py加入下列代碼

from django.contrib import admin
from django.urls import path,include
from rest_framework import routers
from blog import views

router =routers.DefaultRouter()
router.register(r'posts', views.PostViewSet)
router.register(r'tags',views.TagViewSet)
router.register(r'profile', views.ProfileViewSet)

urlpatterns = [
    path('admin/', admin.site.urls),
    path('api/', include(router.urls)),
    path('api-auth/', include('rest_framework.urls', namespace='rest_framework'))
]

配置drf_backend/settings/py

INSTALLED_APPS = [
    ...
    "corsheaders",
    'rest_framework',
    'blog',
]

Pagination (配置Rest API取得每頁的數據數)

REST_FRAMEWORK = {
    'DEFAULT_PAGINATION_CLASS': 'rest_framework.pagination.PageNumberPagination',
    'PAGE_SIZE': 10
}

配置可以訪問的Frontend的地址和埠

CORS_ORIGIN_ALLOW_ALL = False
CORS_ORIGIN_WHITELIST = ("http://localhost:8080",)

在瀏覽器中進入http://localhost:8000/api/ 可以看到Server提供的rest api的相關url,並可以進行操作了.