def cancel(self, request, id):
 """
 desc: 取消任務，進行中的參與者得到報酬
 ret: msg
 err: 404頁面/msg
 input:
 - name: id
 desc: 任務id
 type: string
 required: true
 location: path
 """

from django_filters.rest_framework.filterset import FilterSet

class ProductFilter(FilterSet):

 class Meta(object):
 models = models.Product
 fields = (
  'name', 'category', 'id', )

class PurchasedProductsList(generics.ListAPIView):
 """
 Return a list of all the products that the authenticated
 user has ever purchased, with optional filtering.
 """
 model = Product
 serializer_class = ProductSerializer
 filter_class = ProductFilter

 def get_queryset(self):
 user = self.request.user
 return user.purchase_set.all()

from rest_framework.response import Response
from rest_framework.schemas import SchemaGenerator
from rest_framework.views import APIView
from rest_framework_swagger import renderers

class SwaggerSchemaView(APIView):
 permission_classes = [AllowAny]
 renderer_classes = [
 renderers.OpenAPIRenderer,
 renderers.SwaggerUIRenderer
 ]

 def get(self, request):
 generator = SchemaGenerator()
 schema = generator.get_schema(request=request)

 return Response(schema)

from django.utils.six.moves.urllib import parse as urlparse
from rest_framework.schemas import AutoSchema
import yaml
import coreapi
from rest_framework_swagger.views import get_swagger_view

class CustomSchema(AutoSchema):
 def get_link(self, path, method, base_url):

 view = self.view
 method_name = getattr(view, 'action', method.lower())
 method_docstring = getattr(view, method_name, None).__doc__
 _method_desc = ''

 fields = self.get_path_fields(path, method)

 try:
  a = method_docstring.split('---')
 except:
  fields += self.get_serializer_fields(path, method)
 else:
  yaml_doc = None
  if method_docstring:
  try:
   yaml_doc = yaml.load(a[1])
  except:
   yaml_doc = None

  # Extract schema information from yaml

  if yaml_doc and type(yaml_doc) != str:
  _desc = yaml_doc.get('desc', '')
  _ret = yaml_doc.get('ret', '')
  _err = yaml_doc.get('err', '')
  _method_desc = _desc + '\n<br/>' + 'return: ' + _ret + '<br/>' + 'error: ' + _err
  params = yaml_doc.get('input', [])

  for i in params:
   _name = i.get('name')
   _desc = i.get('desc')
   _required = i.get('required', False)
   _type = i.get('type', 'string')
   _location = i.get('location', 'form')
   field = coreapi.Field(
   name=_name,
   location=_location,
   required=_required,
   description=_desc,
   type=_type
   )
   fields.append(field)
  else:
  _method_desc = a[0]
  fields += self.get_serializer_fields(path, method)

 fields += self.get_pagination_fields(path, method)
 fields += self.get_filter_fields(path, method)

 manual_fields = self.get_manual_fields(path, method)
 fields = self.update_fields(fields, manual_fields)

 if fields and any([field.location in ('form', 'body') for field in fields]):
  encoding = self.get_encoding(path, method)
 else:
  encoding = None

 if base_url and path.startswith('/'):
  path = path[1:]

 return coreapi.Link(
  url=urlparse.urljoin(base_url, path),
  action=method.lower(),
  encoding=encoding,
  fields=fields,
  description=_method_desc
 )

schema_view = get_swagger_view(title='API')

from .schema_view import schema_view

urlpatterns = [
 url(r'^v1/api/', include([
 url(r'^doc/', schema_view),
 ])),