Add self link and view for preprint subjects relationship (#10619)

* add self link and view for preprint subjects relationship

* Fix permissions issue

* Add required write scopes

---------

Co-authored-by: Brian J. Geiger <bgeiger@pobox.com>

api/preprints/serializers.py

@@ -223,6 +223,11 @@ def subjects_view_kwargs(self):
         # Overrides TaxonomizableSerializerMixin
         return {'preprint_id': '<_id>'}
 
+    @property
+    def subjects_self_view(self):
+        # Overrides TaxonomizableSerializerMixin
+        return 'preprints:preprint-relationships-subjects'
+
     def get_preprint_url(self, obj):
         return absolute_reverse('preprints:preprint-detail', kwargs={'preprint_id': obj._id, 'version': self.context['request'].parser_context['kwargs']['version']})
 

api/preprints/urls.py

@@ -16,6 +16,7 @@
     re_path(r'^(?P<preprint_id>\w+)/files/osfstorage/$', views.PreprintFilesList.as_view(), name=views.PreprintFilesList.view_name),
     re_path(r'^(?P<preprint_id>\w+)/identifiers/$', views.PreprintIdentifierList.as_view(), name=views.PreprintIdentifierList.view_name),
     re_path(r'^(?P<preprint_id>\w+)/relationships/node/$', views.PreprintNodeRelationship.as_view(), name=views.PreprintNodeRelationship.view_name),
+    re_path(r'^(?P<preprint_id>\w+)/relationships/subjects/$', views.PreprintSubjectsRelationship.as_view(), name=views.PreprintSubjectsRelationship.view_name),
     re_path(r'^(?P<preprint_id>\w+)/review_actions/$', views.PreprintActionList.as_view(), name=views.PreprintActionList.view_name),
     re_path(r'^(?P<preprint_id>\w+)/requests/$', views.PreprintRequestListCreate.as_view(), name=views.PreprintRequestListCreate.view_name),
     re_path(r'^(?P<preprint_id>\w+)/subjects/$', views.PreprintSubjectsList.as_view(), name=views.PreprintSubjectsList.view_name),

api/preprints/views.py

@@ -58,7 +58,7 @@
 from api.requests.permissions import PreprintRequestPermission
 from api.requests.serializers import PreprintRequestSerializer, PreprintRequestCreateSerializer
 from api.requests.views import PreprintRequestMixin
-from api.subjects.views import BaseResourceSubjectsList
+from api.subjects.views import BaseResourceSubjectsList, SubjectRelationshipBaseView
 from api.base.metrics import PreprintMetricsViewMixin
 from osf.metrics import PreprintDownload, PreprintView
 
@@ -456,6 +456,37 @@ class PreprintSubjectsList(BaseResourceSubjectsList, PreprintMixin):
     def get_resource(self):
         return self.get_preprint()
 
+
+class PreprintSubjectsRelationship(SubjectRelationshipBaseView, PreprintMixin):
+    """The documentation for this endpoint can be found [here](https://developer.osf.io/#operation/preprint_subjects_list).
+    """
+    permission_classes = (
+        drf_permissions.IsAuthenticatedOrReadOnly,
+        base_permissions.TokenHasScope,
+        ModeratorIfNeverPublicWithdrawn,
+        ContributorOrPublic,
+        PreprintPublishedOrWrite,
+    )
+
+    required_read_scopes = [CoreScopes.PREPRINTS_READ]
+    required_write_scopes = [CoreScopes.PREPRINTS_WRITE]
+
+    view_category = 'preprints'
+    view_name = 'preprint-relationships-subjects'
+
+    def get_resource(self, check_object_permissions=True):
+        return self.get_preprint(check_object_permissions=check_object_permissions)
+
+    def get_object(self):
+        resource = self.get_resource(check_object_permissions=False)
+        obj = {
+            'data': resource.subjects.all(),
+            'self': resource,
+        }
+        self.check_object_permissions(self.request, resource)
+        return obj
+
+
 class PreprintActionList(JSONAPIBaseView, generics.ListCreateAPIView, ListFilterMixin, PreprintMixin):
     """Action List *Read-only*