Use ViewSet for Gene API

backend/metagenedb/api/catalog/urls.py

 from django.urls import re_path
 
-from . import views
+from django.conf.urls import url, include
+from rest_framework.routers import DefaultRouter
+
+from metagenedb.api.catalog.views import GeneViewSet, gene_length
+
+
+api_router = DefaultRouter()
+api_router.register(r'genes', GeneViewSet, 'genes')
 
 
 urlpatterns = [
-    re_path(r'^genes/$', views.gene_list, name='genes'),
-    re_path(r'^genes/(?P<gene_id>.*)$', views.gene_detail),
-    re_path(r'^gene_length$', views.gene_length, name='gene_length'),
+    re_path(r'^gene_length$', gene_length, name='gene_length'),
+    url(r'v1/', include(api_router.urls))
 ]

backend/metagenedb/api/catalog/views/__init__.py

-from .gene import gene_detail, gene_list  # noqa
-from .statistics import gene_length  # noqa
\ No newline at end of file
+from .gene import GeneViewSet  # noqa
+from .statistics import gene_length  # noqa
+
+__all__ = ['GeneViewSet']

backend/metagenedb/api/catalog/views/gene.py

-import logging
-
-from rest_framework import status
-from rest_framework.decorators import (
-    api_view,
-    authentication_classes,
-    permission_classes
-)
-from rest_framework.response import Response
-from django.core.paginator import Paginator, EmptyPage, PageNotAnInteger
+from rest_framework.viewsets import GenericViewSet
+from rest_framework import mixins
 
 from metagenedb.apps.catalog.models import Gene
 from metagenedb.apps.catalog.serializers import GeneSerializer
 
-logging.basicConfig(level=logging.INFO)
-_LOGGER = logging.getLogger(__name__)
-
 
-@api_view(['GET'])
-@authentication_classes(())
-@permission_classes(())
-def gene_list(request):
+class GeneViewSet(mixins.ListModelMixin,
+                  mixins.RetrieveModelMixin,
+                  GenericViewSet):
     """
-    List genes
+    The following endpoints are fully provided by mixins:
+    * List gene
     """
-    next_page = 1
-    previous_page = 1
-    genes = Gene.objects.all()
-    page = request.GET.get('page', 1)
-    paginator = Paginator(genes, 10)
-    try:
-        data = paginator.page(page)
-    except PageNotAnInteger:
-        data = paginator.page(1)
-    except EmptyPage:
-        data = paginator.page(paginator.num_pages)
-
-    serializer = GeneSerializer(data, context={'request': request}, many=True)
-    if data.has_next():
-        next_page = data.next_page_number()
-    if data.has_previous():
-        previous_page = data.previous_page_number()
-
-    return Response(
-        {'data': serializer.data, 'count': paginator.count, 'numpages': paginator.num_pages,
-         'nextlink': '/api/genes/?page=' + str(next_page),
-         'prevlink': '/api/genes/?page=' + str(previous_page)}
-    )
-
-
-@api_view(['GET'])
-def gene_detail(request, gene_id):
-    """
-    Retrieve, update or delete a gene instance.
-    """
-    try:
-        gene = Gene.objects.get(gene_id=gene_id)
-    except Gene.DoesNotExist:
-        return Response(status=status.HTTP_404_NOT_FOUND)
-
-    serializer = GeneSerializer(gene, context={'request': request})
-    return Response(serializer.data)
+    queryset = Gene.objects.all()
+    serializer_class = GeneSerializer

backend/metagenedb/apps/catalog/serializers.py

-from rest_framework import serializers
-from .models import Gene, Function
-
-
-class FunctionSerializer(serializers.ModelSerializer):
-    class Meta:
-        model = Function
-        fields = ('function_id', 'source', 'name')
-
-
-class GeneSerializer(serializers.ModelSerializer):
-    functions = FunctionSerializer(many=True, read_only=True)
-
-    class Meta:
-        model = Gene
-        fields = ('gene_id', 'gene_length', 'functions')