05_Tutorial 5: Relationships & Hyperlinked APIs 关系和超链接
1、关系和超链接
0、文档
https://www.django-rest-framework.org/tutorial/5-relationships-and-hyperlinked-apis/
1、效果
2、name用法，配合reverse
第一，我们使用REST框架的reverse功能来返回完全限定的URL；
第二，URL模式是通过方便的名称来标识的，我们稍后将在snippets/urls.py中声明。
view
from rest_framework.reverse import reverse urlpatterns = format_suffix_patterns([ path('', views.api_root), # 主index页面 path('snippets/', views.SnippetList.as_view(), name='snippet-list'), # name用法，配合reverse('snippet-list') path('snippets/<int:pk>/', views.SnippetDetail.as_view(), name='snippet-detail'), path('snippets/<int:pk>/highlight/', views.SnippetHighlight.as_view(), name='snippet-highlight'), path('users/', views.UserList.as_view(), name='user-list'), path('users/<int:pk>', views.UserDetail.as_view(), name='user-detail'), ])
model
@api_view(['GET']) def api_root(request, format=None): # 入口，首页 return Response({ 'users': reverse('user-list', request=request, format=format), # reverse 反转 'snippets': reverse('snippet-list', request=request, format=format), })
3、 超链接序列化：HyperlinkedModelSerializer
处理好实体之间的关系：希望在实体之间使用超链接方式
view视图不变
class UserList(generics.ListAPIView): # user/ get方式 queryset = User.objects.all().order_by('id') serializer_class = UserSerializer
序列化：继承HyperModelSerilizer
class UserSerializer(serializers.HyperlinkedModelSerializer): # 实体之间使用超链接方式 # snippets = serializers.PrimaryKeyRelatedField(many=True, queryset=Snippet.objects.all()) # 添加一个显式字段 外键 # 关联关系，alex的snippet的详情 # many=True，多个字段， snippets = serializers.HyperlinkedRelatedField(many=True, view_name='snippet-detail', read_only=True) class Meta: model = User fields = ['url', 'id', 'username', 'snippets'] class SnippetSerializer(serializers.ModelSerializer): owner = serializers.ReadOnlyField(source='owner.username') # source参数控制哪个属性用于填充字段 # # 它包含一个url字段 该snippet的highlight # 单个字段，继承与HyperlinkedRelatedField highlight = serializers.HyperlinkedIdentityField(view_name='snippet-highlight', format='html') class Meta: model = Snippet fields = ['url', 'id', 'title', 'code', 'linenos', 'language', 'style', 'owner', 'highlight']
4、HyperlinkedModelSerialize与ModelSerializer区别
HyperlinkedModelSerializer与ModelSerializer有以下区别：
- 默认情况下不包括
id字段。 - 它包含一个
url字段，使用HyperlinkedIdentityField。 - 关联关系使用
HyperlinkedRelatedField，而不是PrimaryKeyRelatedField。
5、高亮代码
model层
class Snippet(models.Model): created = models.DateTimeField(auto_now_add=True) # 创建时间 title = models.CharField(max_length=100, blank=True, default='') code = models.TextField() linenos = models.BooleanField(default=False) # choices = [(1,'java'),(2,'python'),(3,''golang')] # 下拉框选择，指代 language = models.CharField(choices=LANGUAGE_CHOICES, default='python', max_length=100) style = models.CharField(choices=STYLE_CHOICES, default='friendly', max_length=100) # Tutorial 4: Authentication & Permissions owner = models.ForeignKey('auth.User', related_name='snippets', on_delete=models.CASCADE) # 设置related_name参数来覆盖原名称owner_id(ORM查询时)，实质，DB中还是owner_id highlighted = models.TextField() class Meta: ordering = ['created'] # def save(self, force_insert=False, force_update=False, using=None, update_fields=None): def save(self, *args, **kwargs): """ 使用pygments库，创建一个高亮显示的HTML，表示代码段 """ lexer = get_lexer_by_name(self.language) linenos = self.linenos and 'table' or False options = self.title and {'title': self.title} or {} formatter = HtmlFormatter(style=self.style, linenos=linenos, full=True, **options) self.highlighted = highlight(self.code, lexer, formatter) super(Snippet, self).save(*args, **kwargs) # 继承父类Model的save
6、HTML渲染器
一个HTML渲染器类，简单地返回预渲染的HTML
data = '<html><body>example</body></html>'
return Response(data)
view层
from rest_framework import renderers class SnippetHighlight(generics.GenericAPIView): queryset = Snippet.objects.all() renderer_classes = [renderers.StaticHTMLRenderer] def get(self, request, *args, **kwargs): snippet = self.get_object() # 视图显示的对象。 return Response(snippet.highlighted) # 某个字段
