Django rest_framework 实用技巧

Posted 2020-08-26

前言:

　　最近工作中需要用到Django rest_framework框架做API, 边学边写,记录了一些实际工作中需要用到的功能,不是很全也不系统,以后需要什么功能可以在这查询. 后续还会更新其它的用法

  1 ####################################################################
  2 ########安装和简单使用
  3     ###### 准备工作
  4         pip install rest_framework  # 安装
  5 
  6         INSTALLED_APPS = (
  7             ...
  8             ‘rest_framework‘,   # 将其加入app列表内
  9         )
 10 
 11 
 12     ###### urls.py 
 13         from django.conf.urls import include, url  # 引入include二级路由, url
 14         from django.contrib import admin           # admin模块
 15         from rest_framework import routers         # 导入api路由 !
 16         import app1         # 导入app1
 17 
 18         router = routers.DefaultRouter()           # 获取api路由对象
 19         router.register(r‘users‘, app1.SpecialGiftViewSet)# 注册路由到指定的ViewSet类
 20 
 21         urlpatterns = [
 22             url(r‘^admin/‘, include(admin.site.urls)),  
 23             url(r‘^‘, include(router.urls)),       # 设置api路由转发
 24         ]
 25 
 26 
 27     ###### app1/serializers.py
 28         from rest_framework import serializers  # api接口用于序列化 model 的类
 29         from app1.models import SpecialGift     # 自定义的要提供api的model类
 30 
 31         class UserSerializer(serializers.HyperlinkedModelSerializer):  # 序列化这个表的类
 32             class Meta:
 33                 model = SpecialGift
 34                 fields = (‘url‘, ‘username‘, ‘email‘, ‘is_staff‘)      # 验证字段可以省略!
 35 
 36         ---------参数扩展-----------
 37         # HyperlinkedModelSerializer 是建立超链接关系就是外健使用 "goods": "http://127.0.0.1:8080/goods/1/"
 38         # ModelSerializer  建立主健关系在json数据中表现为 ‘goods‘: 1
 39         # ReadOnlyModelViewSet  未知
 40      
 41 
 42     ####### app1/views.py 内容
 43         from rest_framework import routers, serializers, viewsets      # 分别为api的路由, 序列化, viewsets
 44         from app1.serializers import SpecialGiftSerializer           # 引入处理序列化的类
 45         from rest_framework.permissions import AllowAny, IsAuthenticated, IsAdminUser  # 用于指定权限, 所有人, 登录用户, 管理员
 46         from app01.models import SpecialGift                  # 引入models类
 47         from django.utils import timezone    # 按时区的,当前时间
 48         # from rest_framework import response
 49 
 50         class SpecialGiftViewSet(viewsets.ReadOnlyModelViewSet):
 51             queryset = SpecialGift.objects.all().order_by(‘-created‘)    # 指定默认查询方式, 按创建时间倒序
 52             serializer_class = SpecialGiftSerializer                  # 指定处理序列化的类
 53             permission_classes = [AllowAny]                        # 指定权限 AllowAny 为所有人
 54 
 55             def get_queryset(self):  # 过滤函数
 56                 return self.queryset.filter(end_time__gt=timezone.now())  # 过滤当前时间以前的记录
 57 
 58 
 59 
 60     ###### app1/models.py 中写入模型定义
 61         from django.utils.translation import ugettext_lazy as _  # Django国际化翻译
 62         
 63         class SpecialGift(models.Model):
 64         title = models.CharField(max_length=64)
 65         image = VersatileImageField(_("gift_image"),
 66                                     max_length=255,
 67                                     upload_to=generate_upload_filename,
 68                                     )
 69         min_money = models.DecimalField(_("min_money"), max_digits=7, decimal_places=2, validators=[MinValueValidator(0)])
 70         price = models.DecimalField(_("price"), max_digits=7, decimal_places=2, validators=[MinValueValidator(0)],
 71                                     default=29.9)
 72         end_time = models.DateTimeField()
 73 
 74         def __unicode__(self):
 75             return self.title
 76 
 77 
 78     ###### app1/admin.py 中配置管理界面
 79         from django.contrib import admin
 80         from app1.models import SpecialGift
 81 
 82         admin.site.register(SpecialGift)  # 简单注册每行只显示对象名
 83 
 84         # 装饰器注册!
 85         @admin.register(SpecialGift)
 86         class SpecialGiftAdmin(admin.ModelAdmin):
 87             list_display = (‘title‘, ‘image‘, ‘min_money‘, ‘price‘, ‘end_time‘)  # 显示为表结构包括所有的列
 88             search_fields = [‘title‘]  # 出现搜索框, 指定搜索哪一列字段
 89 
 90         # 在django中我们没有创建对数据库的查询操作和页面返回，但是调用rest framework标准的api接口我们就可以直接从数据库中查询到数据，增删改查都是可以的！实现起来如此简单！
 91 
 92 
 93     ###### setting.py配置
 94     REST_FRAMEWORK = {
 95         ‘DEFAULT_PERMISSION_CLASSES‘: (‘rest_framework.permissions.DjangoModelPermissionsOrAnonReadOnly‘,),
 96         ‘DEFAULT_FILTER_BACKENDS‘: (‘rest_framework.filters.DjangoFilterBackend‘,),
 97         ‘DEFAULT_PAGINATION_CLASS‘: ‘rest_framework.pagination.PageNumberPagination‘,
 98         ‘DEFAULT_VERSIONING_CLASS‘: ‘rest_framework.versioning.AcceptHeaderVersioning‘,
 99         ‘DEFAULT_VERSION‘: ‘160201‘,
100         ‘PAGE_SIZE‘: 10,   # 每页10条数据
101         ‘DEFAULT_AUTHENTICATION_CLASSES‘: (
102             ‘rest_framework.authentication.SessionAuthentication‘,
103             ‘rest_framework.authentication.TokenAuthentication‘,
104         ),
105     }
106 
107 
108 
109 
110 #######################################################################
111 # 为查询到的数据增加相关联的字段!! 正查!!
112 #######################################################################
113     # models.py
114     class Goods(models.Model):
115         name = models.CharField(max_length=128)
116         price = models.CharField(max_length=56, blank=True, null=True)
117 
118 
119     class Index(models.Model):
120         goods = models.ForeignKey(Goods, verbose_name="Goods")
121         start_at = models.DateTimeField()
122         end_at = models.DateTimeField()
123 
124 
125     # serializers.py
126     class GoodsSerializers(serializers.HyperlinkedModelSerializer):
127         class Meta:
128             model = Goods
129             fields = (‘name‘, ‘price‘)
130 
131 
132     class IndexSerializers(serializers.HyperlinkedModelSerializer):
133         name = serializers.ReadOnlyField(source=‘goods.name‘)    # 增加外健的字段
134         price = serializers.ReadOnlyField(source=‘goods.price‘)  # 添加外健的字段 
135 
136         class Meta:
137             model = Index
138             fields = (‘goods‘, ‘start_at‘, ‘end_at‘, ‘name‘, ‘price‘)
139 
140 
141     # views.py
142     class IndexViewSet(viewsets.ReadOnlyModelViewSet):
143         queryset = Index.objects.all()
144         serializer_class = IndexSerializers
145 
146 
147     class GoodsViewSet(viewsets.ReadOnlyModelViewSet):
148         queryset = Goods.objects.all()
149         serializer_class = GoodsSerializers
150 
151     # 结果! 商品本来只有一个url接口要起得到详细还得再查询一次.现在将详细直接加入数据中方便很多!
152     {
153         "count": 2,
154         "next": null,
155         "previous": null,
156         "results": [
157             {
158                 "goods": "http://127.0.0.1:8080/goods/1/",
159                 "start_at": "2017-01-03T14:22:55Z",
160                 "end_at": "2017-01-03T14:22:56Z",
161                 "name": "book",
162                 "price": "18.5"
163             },
164             {
165                 "goods": "http://127.0.0.1:8080/goods/2/",
166                 "start_at": "2017-01-03T14:23:04Z",
167                 "end_at": "2017-01-03T14:23:05Z",
168                 "name": "pen",
169                 "price": "34.5"
170             }
171         ]
172     }
173 
174 
175 
176 
177 ################################################################################
178 ###### api嵌套查询, 查询外健对象的具具体内容, 而不是只显示iD
179 ###### 正查例子
180     class Column(models.Model):
181         name = models.CharField(u‘类型名称‘, max_length=256)
182         slug = models.CharField(u‘类型网址‘, max_length=256, db_index=True)
183         intro = models.TextField(u‘类型简介‘, default=‘‘)
184 
185     class Article(models.Model):
186         column = models.ManyToManyField(Column, verbose_name=u‘分类‘)
187         genre = models.SmallIntegerField(u‘文本<图片<视频‘, choices=ARTICLE_GENRE, default=ARTICLE_TXT,
188                                          help_text=u‘文章所属类型. 优先级别视频大于图片大于文本‘)
189 
190     # article的models里面有多对多的外健column字段
191     class ColumnSerializer(serializers.ModelSerializer):
192         class Meta:
193             model = Column
194 
195     class ArticleSerializer(serializers.ModelSerializer):
196         column = ColumnSerializer(many=True, read_only=False)  # 定义和外健字段重名的字段并为其指定序列化类
197         class Meta:
198             model = Article
199             fields = (‘title‘, ‘column‘)   # 定义只操作这两列数据(如果不定义fields则默认为全部字段, 如果定义fields则
200                                            # _必须包含本类中定义的column字段, 否则报错)
201 
202     class ArticleViewSet(viewsets.ReadOnlyModelViewSet):        # view.py
203             queryset = Article.objects.all()                    # 查询
204             serializer_class = ArticleSerializer                # 指定序列化类
205 
206 
207 
208 
209 
210 ###### 反查例子:
211     # 还用上面的models为例再加个评论表, 外健分别为User, Article, 通过Article查询评论的内容如下
212     class Comment(models.Model):
213         owner = models.ForeignKey(‘auth.User‘)
214         article = models.ForeignKey(Article, related_name=‘comments‘)  # 注意反查名
215         content = models.CharField(u‘评论内容‘, max_length=1024)
216         flag = models.BooleanField(u‘标记‘, default=True)
217         updated = models.DateTimeField(auto_now=True)
218         created = models.DateTimeField(auto_now_add=True)
219 
220     class CommentSerializer(serializers.ModelSerializer):   # 为此表定义序列化类
221         class Meta:
222             model = Comment
223 
224     class ArticleSerializer(serializers.ModelSerializer):
225         column = ColumnSerializer(many=True, read_only=False)
226         comments = CommentSerializer(many=True, read_only=False)  # 使用反查名指定序列化类
227         class Meta:
228             model = Article
229 
230     class ArticleViewSet(viewsets.ReadOnlyModelViewSet):    # view.py
231         queryset = Article.objects.all()                    # 查询
232         serializer_class = ArticleSerializer                # 指定序列化类
233         def get_queryset(self):                        # 过滤函数
234             return self.queryset.filter(end_time__gt=timezone.now())
235 
236 
237 
238 
239 
240 ################################################################################
241 ######关于class Meta的其它功能
242     class ArticleSerializer(serializers.ModelSerializer):
243         column = ColumnSerializer(many=True, read_only=False)  # 定义和外健字段重名的字段并为其指定序列化类
244         class Meta:
245             model = Article          # 定义对应的model
246 
247             exclude = (‘id‘, )        # 定义排除这几列数据
248 
249             fields = (‘title‘, ‘column‘)   # 定义只操作这两列数据(如果不定义,默认是全部数据)
250 
251             read_only_fields = (‘id‘, ‘user‘)  # 定义这几列数据是只读的