Support formatting URL segments via new FORMAT_LINKS setting

Fixes #790.

Author: platinumazure

Diff for: AUTHORS

@@ -15,6 +15,7 @@ Jason Housley <[email protected]>
 Jerel Unruh <[email protected]>
 Jonathan Senecal <[email protected]>
 Joseba Mendivil <[email protected]>
+Kevin Partington <[email protected]>
 Kieran Evans <[email protected]>
 Léo S. <[email protected]>
 Luc Cary <[email protected]>

Diff for: CHANGELOG.md

@@ -13,6 +13,7 @@ any parts of the framework not mentioned in the documentation should generally b
 ### Added
 
 * Ability for the user to select `included_serializers` to apply when using `BrowsableAPI`, based on available `included_serializers` defined for the current endpoint.
+* Ability for the user to format serializer properties in URL segments using the `JSON_API_FORMAT_LINKS` setting.
 
 ### Fixed
 

Diff for: docs/usage.md

@@ -477,6 +477,44 @@ When set to pluralize:
 }
 ```
 
+#### Related URL segments
+
+Serializer properties in relationship and related resource URLs may be infected using the `JSON_API_FORMAT_LINKS` setting.
+
+``` python
+JSON_API_FORMAT_LINKS = 'dasherize'
+```
+
+For example, with a serializer property `created_by` and with `'dasherize'` formatting:
+
+```json{
+{
+  "data": {
+      "type": "comments",
+      "id": "1",
+      "attributes": {
+          "text": "Comments are fun!"
+      },
+      "links": {
+          "self": "/comments/1"
+      },
+      "relationships": {
+        "created_by": {
+          "links": {
+            "self": "/comments/1/relationships/created-by",
+            "related": "/comments/1/created-by"
+          }
+        }
+      }
+  },
+  "links": {
+      "self": "/comments/1"
+  }
+}
+```
+
+The relationship name is formatted by the `JSON_API_FORMAT_FIELD_NAMES` setting, but the URL segments are formatted by the `JSON_API_FORMAT_LINKS` setting.
+
 ### Related fields
 
 #### ResourceRelatedField

Diff for: rest_framework_json_api/relations.py

@@ -13,8 +13,10 @@
 from rest_framework.serializers import Serializer
 
 from rest_framework_json_api.exceptions import Conflict
+from rest_framework_json_api.settings import json_api_settings
 from rest_framework_json_api.utils import (
     Hyperlink,
+    format_value,
     get_included_serializers,
     get_resource_type_from_instance,
     get_resource_type_from_queryset,
@@ -112,13 +114,11 @@ def get_links(self, obj=None, lookup_field="pk"):
             else view.kwargs[lookup_field]
         }
 
+        field_name = self.field_name if self.field_name else self.parent.field_name
+
         self_kwargs = kwargs.copy()
         self_kwargs.update(
-            {
-                "related_field": self.field_name
-                if self.field_name
-                else self.parent.field_name
-            }
+            {"related_field": format_value(field_name, json_api_settings.FORMAT_LINKS)}
         )
         self_link = self.get_url("self", self.self_link_view_name, self_kwargs, request)
 

Diff for: rest_framework_json_api/settings.py

@@ -12,6 +12,7 @@
 DEFAULTS = {
     "FORMAT_FIELD_NAMES": False,
     "FORMAT_TYPES": False,
+    "FORMAT_LINKS": False,
     "PLURALIZE_TYPES": False,
     "UNIFORM_EXCEPTIONS": False,
 }

Diff for: rest_framework_json_api/utils.py

@@ -148,6 +148,19 @@ def format_resource_type(value, format_type=None, pluralize=None):
     return inflection.pluralize(value) if pluralize else value
 
 
+def format_link_segment(value, format_type=None):
+    """
+    Takes a string value and returns it with formatted keys as set in `format_type`
+    or `JSON_API_FORMAT_LINKS`.
+
+    :format_type: Either 'dasherize', 'camelize', 'capitalize' or 'underscore'
+    """
+    if format_type is None:
+        format_type = json_api_settings.FORMAT_LINKS
+
+    return format_value(value, format_type)
+
+
 def get_related_resource_type(relation):
     from rest_framework_json_api.serializers import PolymorphicModelSerializer
 

Diff for: rest_framework_json_api/views.py

@@ -25,6 +25,7 @@
 from rest_framework_json_api.utils import (
     Hyperlink,
     OrderedDict,
+    format_value,
     get_included_resources,
     get_resource_type_from_instance,
 )
@@ -185,7 +186,8 @@ def get_related_serializer_class(self):
         return parent_serializer_class
 
     def get_related_field_name(self):
-        return self.kwargs["related_field"]
+        field_name = self.kwargs["related_field"]
+        return format_value(field_name, "underscore")
 
     def get_related_instance(self):
         parent_obj = self.get_object()
@@ -227,7 +229,6 @@ class RelationshipView(generics.GenericAPIView):
     serializer_class = ResourceIdentifierObjectSerializer
     self_link_view_name = None
     related_link_view_name = None
-    field_name_mapping = {}
     http_method_names = ["get", "post", "patch", "delete", "head", "options"]
 
     def get_serializer_class(self):
@@ -400,9 +401,7 @@ def get_related_instance(self):
 
     def get_related_field_name(self):
         field_name = self.kwargs["related_field"]
-        if field_name in self.field_name_mapping:
-            return self.field_name_mapping[field_name]
-        return field_name
+        return format_value(field_name, "underscore")
 
     def _instantiate_serializer(self, instance):
         if isinstance(instance, Model) or instance is None:

Diff for: tests/test_relations.py

@@ -0,0 +1,46 @@
+import pytest
+
+from rest_framework_json_api.relations import HyperlinkedRelatedField
+
+from .models import BasicModel
+
+
+@pytest.mark.urls("tests.urls")
+@pytest.mark.parametrize(
+    "format_links,expected_url_segment",
+    [
+        (None, "relatedField_name"),
+        ("dasherize", "related-field-name"),
+        ("camelize", "relatedFieldName"),
+        ("capitalize", "RelatedFieldName"),
+        ("underscore", "related_field_name"),
+    ],
+)
+def test_relationship_urls_respect_format_links(
+    settings, format_links, expected_url_segment
+):
+    settings.JSON_API_FORMAT_LINKS = format_links
+
+    model = BasicModel(text="Some text")
+
+    field = HyperlinkedRelatedField(
+        self_link_view_name="basic-model-relationships",
+        related_link_view_name="basic-model-related",
+        read_only=True,
+    )
+    field.field_name = "relatedField_name"
+
+    expected = {
+        "self": "/basic_models/{}/relationships/{}/".format(
+            model.pk,
+            expected_url_segment,
+        ),
+        "related": "/basic_models/{}/{}/".format(
+            model.pk,
+            expected_url_segment,
+        ),
+    }
+
+    actual = field.get_links(model)
+
+    assert expected == actual

Diff for: tests/test_utils.py

@@ -8,6 +8,7 @@
 from rest_framework_json_api import serializers
 from rest_framework_json_api.utils import (
     format_field_names,
+    format_link_segment,
     format_resource_type,
     format_value,
     get_included_serializers,
@@ -197,6 +198,21 @@ def test_format_field_names(settings, format_type, output):
     assert format_field_names(value, format_type) == output
 
 
+@pytest.mark.parametrize(
+    "format_type,output",
+    [
+        (None, "first_Name"),
+        ("camelize", "firstName"),
+        ("capitalize", "FirstName"),
+        ("dasherize", "first-name"),
+        ("underscore", "first_name"),
+    ],
+)
+def test_format_field_segment(settings, format_type, output):
+    settings.JSON_API_FORMAT_LINKS = format_type
+    assert format_link_segment("first_Name") == output
+
+
 @pytest.mark.parametrize(
     "format_type,output",
     [

Diff for: tests/test_views.py

@@ -0,0 +1,51 @@
+import pytest
+from django.test import RequestFactory
+
+from rest_framework_json_api import serializers, views
+from rest_framework_json_api.relations import ResourceRelatedField
+from rest_framework_json_api.utils import format_value
+
+from .models import BasicModel
+
+related_model_field_name = "related_field_model"
+
+
+@pytest.mark.urls("tests.urls")
+@pytest.mark.parametrize(
+    "format_links",
+    [
+        None,
+        "dasherize",
+        "camelize",
+        "capitalize",
+        "underscore",
+    ],
+)
+def test_get_related_field_name_handles_formatted_link_segments(format_links):
+    url_segment = format_value(related_model_field_name, format_links)
+
+    request = RequestFactory().get("/basic_models/1/{}".format(url_segment))
+
+    view = BasicModelFakeViewSet()
+    view.setup(request, related_field=url_segment)
+
+    assert view.get_related_field_name() == related_model_field_name
+
+
+class BasicModelSerializer(serializers.ModelSerializer):
+    related_model_field = ResourceRelatedField(queryset=BasicModel.objects)
+
+    def __init__(self, *args, **kwargs):
+        # Intentionally setting field_name property to something that matches no format
+        self.related_model_field.field_name = related_model_field_name
+        super(BasicModelSerializer, self).__init(*args, **kwargs)
+
+    class Meta:
+        model = BasicModel
+
+
+class BasicModelFakeViewSet(views.ModelViewSet):
+    serializer_class = BasicModelSerializer
+
+    def retrieve(self, request, *args, **kwargs):
+        pass

Diff for: tests/urls.py

@@ -0,0 +1,22 @@
+from django.conf.urls import re_path
+from rest_framework.routers import SimpleRouter
+
+from .views import BasicModelRelationshipView, BasicModelViewSet
+
+router = SimpleRouter()
+router.register(r"basic_models", BasicModelViewSet, basename="basic-model")
+
+urlpatterns = [
+    re_path(
+        r"^basic_models/(?P<pk>[^/.]+)/(?P<related_field>[^/.]+)/$",
+        BasicModelViewSet.as_view({"get": "retrieve_related"}),
+        name="basic-model-related",
+    ),
+    re_path(
+        r"^basic_models/(?P<pk>[^/.]+)/relationships/(?P<related_field>[^/.]+)/$",
+        BasicModelRelationshipView.as_view(),
+        name="basic-model-relationships",
+    ),
+]
+
+urlpatterns += router.urls

Diff for: tests/views.py

@@ -0,0 +1,12 @@
+from rest_framework_json_api.views import ModelViewSet, RelationshipView
+
+from .models import BasicModel
+
+
+class BasicModelViewSet(ModelViewSet):
+    class Meta:
+        model = BasicModel
+
+
+class BasicModelRelationshipView(RelationshipView):
+    queryset = BasicModel.objects