fix read_only related field metadata

Author: Jannon Frank

rest_framework/metadata.py

@@ -127,13 +127,14 @@ def get_field_info(self, field):
             if value is not None and value != '':
                 field_info[attr] = force_text(value, strings_only=True)
 
-        if hasattr(field, 'choices'):
-            field_info['choices'] = [
-                {
-                    'value': choice_value,
-                    'display_name': force_text(choice_name, strings_only=True)
-                }
-                for choice_value, choice_name in field.choices.items()
-            ]
+        if 'read_only' in field_info and not field_info['read_only']:
+            if hasattr(field, 'choices'):
+                field_info['choices'] = [
+                    {
+                        'value': choice_value,
+                        'display_name': force_text(choice_name, strings_only=True)
+                    }
+                    for choice_value, choice_name in field.choices.items()
+                ]
 
         return field_info

tests/test_metadata.py

@@ -1,4 +1,7 @@
 from __future__ import unicode_literals
+from django.db import models
+from django.test import TestCase
+from django.core.validators import MinValueValidator, MaxValueValidator, MinLengthValidator
 from rest_framework import exceptions, metadata, serializers, status, views, versioning
 from rest_framework.request import Request
 from rest_framework.renderers import BrowsableAPIRenderer
@@ -212,3 +215,82 @@ def test_null_boolean_field_info_type(self):
         options = metadata.SimpleMetadata()
         field_info = options.get_field_info(serializers.NullBooleanField())
         assert field_info['type'] == 'boolean'
+
+
+class TestModelSerializerMetadata(TestCase):
+    def test_read_only_primary_key_related_field(self):
+        """
+        On generic views OPTIONS should return an 'actions' key with metadata
+        on the fields that may be supplied to PUT and POST requests. It should
+        not fail when a read_only PrimaryKeyRelatedField is present
+        """
+        class Parent(models.Model):
+            integer_field = models.IntegerField(validators=[MinValueValidator(1), MaxValueValidator(1000)])
+            children = models.ManyToManyField('Child')
+            name = models.CharField(max_length=100, blank=True, null=True)
+
+        class Child(models.Model):
+            name = models.CharField(max_length=100)
+
+        class ExampleSerializer(serializers.ModelSerializer):
+            children = serializers.PrimaryKeyRelatedField(read_only=True, many=True)
+            class Meta:
+                model = Parent
+
+        class ExampleView(views.APIView):
+            """Example view."""
+            def post(self, request):
+                pass
+
+            def get_serializer(self):
+                return ExampleSerializer()
+
+        view = ExampleView.as_view()
+        response = view(request=request)
+        expected = {
+                        'name': 'Example',
+                        'description': 'Example view.',
+                        'renders': [
+                            'application/json',
+                            'text/html'
+                        ],
+                        'parses': [
+                            'application/json',
+                            'application/x-www-form-urlencoded',
+                            'multipart/form-data'
+                        ],
+                        'actions': {
+                            'POST': {
+                                'id': {
+                                    'type': 'integer',
+                                    'required': False,
+                                    'read_only': True,
+                                    'label': 'ID'
+                                },
+                                'children': {
+                                    'type': 'field',
+                                    'required': False,
+                                    'read_only': True,
+                                    'label': 'Children'
+                                },
+                                'integer_field': {
+                                    'type': 'integer',
+                                    'required': True,
+                                    'read_only': False,
+                                    'label': 'Integer field',
+                                    'min_value': 1,
+                                    'max_value': 1000
+                                },
+                                'name': {
+                                    'type': 'string',
+                                    'required': False,
+                                    'read_only': False,
+                                    'label': 'Name',
+                                    'max_length': 100
+                                }
+                            }
+                        }
+                    }
+
+        assert response.status_code == status.HTTP_200_OK
+        assert response.data == expected