Merge pull request #523 from 18F/cursor-api

Add endpoint for serializing trees

api/document/models.py

@@ -44,7 +44,7 @@ def subtree(self, queryset=None):
         if queryset is None:
             queryset = self.__class__.objects
         descendant_models = queryset.filter(
-            left__gt=self.left, right__lt=self.right, policy=self.policy
+            left__gt=self.left, right__lt=self.right, policy_id=self.policy_id
         ).order_by('left')
 
         tree = DiGraph()

api/document/serializers.py

@@ -0,0 +1,23 @@
+from rest_framework import serializers
+
+from document.models import DocNode
+
+
+class DocCursorSerializer(serializers.ModelSerializer):
+    children = serializers.SerializerMethodField()
+
+    class Meta:
+        model = DocNode
+        fields = ('identifier', 'node_type', 'type_emblem', 'text', 'depth',
+                  'children')
+
+    def to_representation(self, instance):
+        """We want to serialize the wrapped model, not the cursor. However, we
+        need to hang on to that cursor for rendering our children."""
+        self.context['cursor'] = instance
+        return super().to_representation(instance.model)
+
+    def get_children(self, instance):
+        return self.__class__(
+            self.context['cursor'].children(), many=True
+        ).data

api/document/tests/serializers_test.py

@@ -0,0 +1,65 @@
+from document import serializers
+from document.models import DocNode
+
+
+def test_end_to_end():
+    """Create a tree, then serialize it."""
+    root = DocNode.new_tree('root', '0')
+    root.add_child('sect', text='Section 1')
+    sect2 = root.add_child('sect')
+    pa = sect2.add_child('par', 'a')
+    pa.add_child('par', '1', text='Paragraph (a)(1)')
+    sect2.add_child('par', 'b')
+
+    result = serializers.DocCursorSerializer(root).data
+    assert result == {
+        'identifier': 'root_0',
+        'node_type': 'root',
+        'type_emblem': '0',
+        'text': '',
+        'depth': 0,
+        'children': [
+            {
+                'identifier': 'root_0__sect_1',
+                'node_type': 'sect',
+                'type_emblem': '1',
+                'text': 'Section 1',
+                'depth': 1,
+                'children': [],
+            },
+            {
+                'identifier': 'root_0__sect_2',
+                'node_type': 'sect',
+                'type_emblem': '2',
+                'text': '',
+                'depth': 1,
+                'children': [
+                    {
+                        'identifier': 'root_0__sect_2__par_a',
+                        'node_type': 'par',
+                        'type_emblem': 'a',
+                        'text': '',
+                        'depth': 2,
+                        'children': [
+                            {
+                                'identifier': 'root_0__sect_2__par_a__par_1',
+                                'node_type': 'par',
+                                'type_emblem': '1',
+                                'text': 'Paragraph (a)(1)',
+                                'depth': 3,
+                                'children': [],
+                            },
+                        ],
+                    },
+                    {
+                        'identifier': 'root_0__sect_2__par_b',
+                        'node_type': 'par',
+                        'type_emblem': 'b',
+                        'text': '',
+                        'depth': 2,
+                        'children': [],
+                    },
+                ],
+            },
+        ],
+    }

api/document/tests/views_test.py

@@ -0,0 +1,49 @@
+import json
+
+import pytest
+from model_mommy import mommy
+
+from document.models import DocNode
+from document.serializers import DocCursorSerializer
+from reqs.models import Policy
+
+
+@pytest.mark.django_db
+@pytest.mark.urls('document.urls')
+def test_404s(client):
+    policy = mommy.make(Policy)
+    root = DocNode.new_tree('root', '0', policy=policy)
+    root.add_child('sect', policy=policy)
+    root.nested_set_renumber()
+    DocNode.objects.bulk_create(n.model for n in root.walk())
+
+    assert client.get("/000001").status_code == 404
+    assert client.get(f"/{policy.pk}").status_code == 200
+    assert client.get(f"/{policy.pk}/root_0").status_code == 200
+    assert client.get(f"/{policy.pk}/root_1").status_code == 404
+    assert client.get(f"/{policy.pk}/root_0__sect_1").status_code == 200
+    assert client.get(f"/{policy.pk}/root_0__sect_2").status_code == 404
+
+
+@pytest.mark.django_db
+@pytest.mark.urls('document.urls')
+def test_correct_data(client):
+    policy = mommy.make(Policy)
+    root = DocNode.new_tree('root', '0', policy=policy)
+    sect1 = root.add_child('sect', policy=policy)
+    root.add_child('sect', policy=policy)
+    sect1.add_child('par', 'a', policy=policy)
+    root.nested_set_renumber()
+    DocNode.objects.bulk_create(n.model for n in root.walk())
+
+    def result(url):
+        return json.loads(client.get(url).content.decode('utf-8'))
+
+    assert result(f"/{policy.pk}") == DocCursorSerializer(root).data
+    assert result(f"/{policy.pk}/root_0") == DocCursorSerializer(root).data
+    assert result(f"/{policy.pk}/root_0__sect_1") \
+        == DocCursorSerializer(root['sect_1']).data
+    assert result(f"/{policy.pk}/root_0__sect_2") \
+        == DocCursorSerializer(root['sect_2']).data
+    assert result(f"/{policy.pk}/root_0__sect_1__par_a") \
+        == DocCursorSerializer(root['sect_1']['par_a']).data

api/document/urls.py

@@ -0,0 +1,8 @@
+from django.conf.urls import url
+
+from document.views import TreeView
+
+urlpatterns = [
+    url(r'^(?P<policy_id>[0-9]+)(/(?P<identifier>[a-zA-Z0-9_-]+))?',
+        TreeView.as_view()),
+]

api/document/views.py

@@ -0,0 +1,19 @@
+from django.shortcuts import get_object_or_404
+from rest_framework.generics import RetrieveAPIView
+
+from document.models import DocNode
+from document.serializers import DocCursorSerializer
+
+
+class TreeView(RetrieveAPIView):
+    serializer_class = DocCursorSerializer
+    queryset = DocNode.objects.none()   # Used to determine permissions
+
+    def get_object(self):
+        query_args = {'policy_id': self.kwargs['policy_id']}
+        if self.kwargs.get('identifier'):
+            query_args['identifier'] = self.kwargs['identifier']
+        else:
+            query_args['depth'] = 0
+        root_struct = get_object_or_404(DocNode, **query_args)
+        return root_struct.subtree()

api/omb_eregs/urls.py

@@ -22,6 +22,7 @@
 urlpatterns = [
     url(r'^', include(router.urls)),
     url(r'^admin/', admin_site.urls),
+    url(r'^document/', include('document.urls')),
 ]
 
 if settings.DEBUG: