Issue 62 - REST API Feature

dbdb/api/pagination.py

@@ -0,0 +1,12 @@
+# third-party imports
+from rest_framework.pagination import LimitOffsetPagination
+
+
+# classes
+
+class StandardPagination(LimitOffsetPagination):
+
+    default_limit = 10
+    max_limit = 100
+
+    pass

dbdb/api/urls.py

@@ -0,0 +1,9 @@
+# django imports
+from django.urls import path
+from django.urls import include
+from django.conf.urls import url
+
+
+urlpatterns = [
+    path('v202004/', include('dbdb.api.v202004.urls')),
+]

dbdb/api/v202004/apps.py

@@ -0,0 +1,5 @@
+from django.apps import AppConfig
+
+
+class ApiV202004Config(AppConfig):
+    name = 'api_v202004'

dbdb/api/v202004/serializers.py

@@ -0,0 +1,177 @@
+# stdlib imports
+import collections
+# third-party imports
+from rest_framework import serializers
+from rest_framework.reverse import reverse
+# project imports
+from dbdb.core.models import FeatureOption
+from dbdb.core.models import System
+from dbdb.core.models import SystemFeature
+
+
+# abstracts
+
+class AbstractSystemSerializer:
+
+
+    def get_acquired_by(self, obj):
+        current = obj.get_current()
+        return current.acquired_by
+
+    def get_countries(self, obj):
+        current = obj.get_current()
+        return list( map(str, current.countries) )
+
+    def get_description(self, obj):
+        current = obj.get_current()
+        return current.description
+
+    def get_developer(self, obj):
+        current = obj.get_current()
+        return current.developer
+
+    def get_features(self, obj):
+        current = obj.get_current()
+
+        sysfeatures = SystemFeature.objects \
+            .filter(system=current) \
+            .select_related('feature') \
+            .order_by('feature__slug')
+
+        items = collections.OrderedDict()
+        for sysfeature in sysfeatures:
+            empty = True
+
+            f = {
+                'name': sysfeature.feature.label,
+            }
+
+            if sysfeature.feature.multivalued:
+                f['values'] = []
+                pass
+            else:
+                f['value'] = None
+                pass
+
+            if sysfeature.feature.multivalued:
+                for option in sysfeature.options.all().order_by('slug'):
+                    f['values'].append(option.value)
+                    empty = False
+            else:
+                option = sysfeature.options.first()
+                if option:
+                    f['value'] = option.value
+                    empty = False
+                pass
+
+            if not empty:
+                items[sysfeature.feature_id] = f
+            pass
+
+        return list( items.values() )
+
+    def get_former_names(self, obj):
+        current = obj.get_current()
+        return current.former_names if current.former_names else None
+
+    def get_history(self, obj):
+        current = obj.get_current()
+        return current.history
+
+    def get_href(self, obj):
+        request = self.context['request']
+        return reverse('system', args=[obj.slug], request=request)
+
+    def get_end_year(self, obj):
+        current = obj.get_current()
+        return current.end_year
+
+    def get_project_types(self, obj):
+        current = obj.get_current()
+        return list( map(str, current.project_types.all()) )
+
+    def get_urls(self, obj):
+        current = obj.get_current()
+        data = {
+            'docs': None if not current.tech_docs else current.tech_docs,
+            'homepage': None if not current.url else current.url,
+            'source': None if not current.source_url else current.source_url,
+            'wikipedia': None if not current.wikipedia_url else current.wikipedia_url,
+        }
+        return data
+
+    def get_start_year(self, obj):
+        current = obj.get_current()
+        return current.start_year
+
+    pass
+
+
+# serializers
+
+class SystemBriefSerializer(AbstractSystemSerializer, serializers.HyperlinkedModelSerializer):
+
+    class Meta:
+        model = System
+        fields = [
+            'url',
+            'href',
+            'name',
+            'start_year',
+            'end_year',
+            'description',
+            'history',
+            'acquired_by',
+            'developer',
+            'project_types',
+        ]
+
+    href = serializers.SerializerMethodField()
+    start_year = serializers.SerializerMethodField()
+    end_year = serializers.SerializerMethodField()
+    description = serializers.SerializerMethodField()
+    history = serializers.SerializerMethodField()
+    acquired_by = serializers.SerializerMethodField()
+    developer = serializers.SerializerMethodField()
+    project_types = serializers.SerializerMethodField()
+    url = serializers.HyperlinkedIdentityField(lookup_field='slug', read_only=True, view_name='api_v202004:systems_view')
+
+    pass
+
+class SystemSerializer(AbstractSystemSerializer, serializers.HyperlinkedModelSerializer):
+
+    class Meta:
+        model = System
+        fields = [
+            'href',
+            'name',
+            'former_names',
+            'start_year',
+            'end_year',
+            'description',
+            'history',
+            'acquired_by',
+            'developer',
+            'countries',
+            'features',
+            'project_types',
+            'urls',
+            'version',
+        ]
+
+    href = serializers.SerializerMethodField()
+    former_names = serializers.SerializerMethodField()
+    start_year = serializers.SerializerMethodField()
+    end_year = serializers.SerializerMethodField()
+    description = serializers.SerializerMethodField()
+    history = serializers.SerializerMethodField()
+    acquired_by = serializers.SerializerMethodField()
+    developer = serializers.SerializerMethodField()
+    countries = serializers.SerializerMethodField()
+    features = serializers.SerializerMethodField()
+    project_types = serializers.SerializerMethodField()
+    urls = serializers.SerializerMethodField()
+    version = serializers.IntegerField(source='ver', read_only=True)
+
+    pass
+

dbdb/api/v202004/urls.py

@@ -0,0 +1,17 @@
+# django imports
+from django.urls import path
+# third-party imports
+from rest_framework.urlpatterns import format_suffix_patterns
+# local imports
+from . import views
+
+
+app_name = 'api_v202004'
+
+urlpatterns = [
+    path('', views.APIRootView.as_view(), name='root'),
+    path('systems', views.SystemsView.as_view(), name='systems'),
+    path('systems/<slug:slug>', views.SystemView.as_view(), name='systems_view'),
+]
+
+urlpatterns = format_suffix_patterns(urlpatterns)

dbdb/api/v202004/views.py

@@ -0,0 +1,59 @@
+# django imports
+from django.shortcuts import render
+# third-party imports
+from rest_framework import generics
+from rest_framework.response import Response
+from rest_framework.reverse import reverse
+from rest_framework.views import APIView
+# project imports
+from dbdb.core.models import System
+from dbdb.core.models import SystemVersion
+# local imports
+from .serializers import SystemBriefSerializer
+from .serializers import SystemSerializer
+
+
+# class based views
+
+class APIRootView(APIView):
+    """
+    Welcome to Database of Databases RESTful API, a public API for accessing out data.
+    """
+
+    def get(self, request):
+
+        data = {
+            'systems': reverse('api_v202004:systems', request=request)
+        }
+
+        return Response(data)
+
+class SystemView(generics.RetrieveAPIView):
+
+    lookup_field = 'slug'
+    queryset = System.objects.all()
+    serializer_class = SystemSerializer
+
+    pass
+
+class SystemsView(generics.ListAPIView):
+
+    queryset = System.objects.all()
+    serializer_class = SystemBriefSerializer
+
+    def paginate_queryset(self, queryset):
+        if self.paginator is None:
+            return None
+
+        items = self.paginator.paginate_queryset(queryset, self.request, view=self)
+
+        # db optimizations - versions
+        ids = { item.id for item in items }
+        versions = SystemVersion.objects.filter(system_id__in=ids, is_current=True)
+        versions_map = { sv.system_id : sv for sv in versions }
+        for item in items:
+            item._current = versions_map[item.id]
+
+        return items
+
+    pass

dbdb/core/models.py

@@ -209,6 +209,16 @@ def current(self):
     def get_absolute_url(self):
         return reverse('system', args=[self.slug])
 
+    def get_current(self):
+        if not hasattr(self, '_current'):
+            if self.id is None:
+                self._current = SystemVersion(system=self)
+            else:
+                self._current = self.versions.get(is_current=True)
+            pass
+
+        return self._current
+
     pass
 
 # ==============================================
@@ -459,6 +469,7 @@ def create_twitter_card(self):
                 text_size = [0, 0]
                 for line in name.split("\n"):
                     line_size = font.getsize(line)
+
                     text_size[0] = max(text_size[0], line_size[0])
                     text_size[1] += line_size[1] + 5