Revert "simplify relationships paths"

This reverts commit 5855b65.

Author: n2ygk

example/tests/test_openapi.py

@@ -128,7 +128,10 @@ def test_schema_construction():
 def test_schema_related_serializers():
     """
     Confirm that paths are generated for related fields. For example:
-        /authors/{pk}/{related_field>}
+    url path '/authors/{pk}/{related_field>}/' generates:
+        /authors/{id}/relationships/comments/
+        /authors/{id}/relationships/entries/
+        /authors/{id}/relationships/first_entry/ -- Maybe?
         /authors/{id}/comments/
         /authors/{id}/entries/
         /authors/{id}/first_entry/
@@ -138,7 +141,12 @@ def test_schema_related_serializers():
     request = create_request('/')
     schema = generator.get_schema(request=request)
     # make sure the path's relationship and related {related_field}'s got expanded
-    assert '/authors/{id}/relationships/{related_field}' in schema['paths']
+    assert '/authors/{id}/relationships/entries' in schema['paths']
+    assert '/authors/{id}/relationships/comments' in schema['paths']
+    # first_entry is a special case (SerializerMethodRelatedField)
+    # TODO: '/authors/{id}/relationships/first_entry' supposed to be there?
+    # It fails when doing the actual GET, so this schema excluding it is OK.
+    # assert '/authors/{id}/relationships/first_entry/' in schema['paths']
     assert '/authors/{id}/comments/' in schema['paths']
     assert '/authors/{id}/entries/' in schema['paths']
     assert '/authors/{id}/first_entry/' in schema['paths']

rest_framework_json_api/schemas/openapi.py

@@ -1,13 +1,15 @@
 import warnings
 from urllib.parse import urljoin
 
+from django.db.models.fields import related_descriptors as rd
 from django.utils.module_loading import import_string as import_class_from_dotted_path
 from rest_framework.fields import empty
 from rest_framework.relations import ManyRelatedField
 from rest_framework.schemas import openapi as drf_openapi
 from rest_framework.schemas.utils import is_list_view
 
 from rest_framework_json_api import serializers
+from rest_framework_json_api.views import RelationshipView
 
 
 class SchemaGenerator(drf_openapi.SchemaGenerator):
@@ -300,7 +302,9 @@ def get_schema(self, request=None, public=False):
         #: - 'action' copy of current view.action (list/fetch) as this gets reset for each request.
         expanded_endpoints = []
         for path, method, view in view_endpoints:
-            if hasattr(view, 'action') and view.action == 'retrieve_related':
+            if isinstance(view, RelationshipView):
+                expanded_endpoints += self._expand_relationships(path, method, view)
+            elif hasattr(view, 'action') and view.action == 'retrieve_related':
                 expanded_endpoints += self._expand_related(path, method, view, view_endpoints)
             else:
                 expanded_endpoints.append((path, method, view, getattr(view, 'action', None)))
@@ -346,6 +350,28 @@ def get_schema(self, request=None, public=False):
 
         return schema
 
+    def _expand_relationships(self, path, method, view):
+        """
+        Expand path containing .../{id}/relationships/{related_field} into list of related fields.
+        :return:list[tuple(path, method, view, action)]
+        """
+        queryset = view.get_queryset()
+        if not queryset.model:
+            return [(path, method, view, getattr(view, 'action', '')), ]
+        result = []
+        # TODO: what about serializer-only (non-model) fields?
+        #       Shouldn't this be iterating over serializer fields rather than model fields?
+        #       Look at parent view's serializer to get the list of fields.
+        #       OR maybe like _expand_related?
+        m = queryset.model
+        for field in [f for f in dir(m) if not f.startswith('_')]:
+            attr = getattr(m, field)
+            if isinstance(attr, (rd.ReverseManyToOneDescriptor, rd.ForwardOneToOneDescriptor)):
+                action = 'rels' if isinstance(attr, rd.ReverseManyToOneDescriptor) else 'rel'
+                result.append((path.replace('{related_field}', field), method, view, action))
+
+        return result
+
     def _expand_related(self, path, method, view, view_endpoints):
         """
         Expand path containing .../{id}/{related_field} into list of related fields