Allow i18n of colander error messages

Fix Cornices#200

cornice/__init__.py

@@ -2,6 +2,7 @@
 # License, v. 2.0. If a copy of the MPL was not distributed with this file,
 # You can obtain one at http://mozilla.org/MPL/2.0/.
 import logging
+from functools import partial
 
 from cornice import util
 from cornice.errors import Errors  # NOQA
@@ -13,9 +14,10 @@
     add_deserializer,
 )
 from cornice.util import ContentTypePredicate
-
+from pyramid.i18n import get_localizer
 from pyramid.httpexceptions import HTTPNotFound, HTTPForbidden
 from pyramid.security import NO_PERMISSION_REQUIRED
+from pyramid.threadlocal import get_current_registry
 
 logger = logging.getLogger('cornice')
 __version__ = "0.17"
@@ -32,6 +34,25 @@ def add_apidoc(config, pattern, func, service, **kwargs):
     info['func'] = func
 
 
+def get_available_locales():
+    settings = get_current_registry().settings
+    if 'available_languages' in settings:
+        return settings['available_languages'].split()
+    else:
+        return []
+
+
+def set_localizer_for_languages(event, available_languages,
+                                default_locale_name):
+    request = event.request
+    if request.accept_language:
+        accepted = request.accept_language
+        locale = accepted.best_match(available_languages, default_locale_name)
+        request._LOCALE_ = locale
+    localizer = get_localizer(request)
+    request.localizer = localizer
+
+
 def includeme(config):
     """Include the Cornice definitions
     """
@@ -56,3 +77,12 @@ def includeme(config):
                         permission=NO_PERMISSION_REQUIRED)
         config.add_view(handle_exceptions, context=HTTPForbidden,
                         permission=NO_PERMISSION_REQUIRED)
+
+    if settings.get('available_languages'):
+        available_languages = settings['available_languages'].split()
+        default_locale_name = settings.get('pyramid.default_locale_name', 'en')
+        set_localizer = partial(set_localizer_for_languages,
+                                available_languages=available_languages,
+                                default_locale_name=default_locale_name)
+        config.add_subscriber(set_localizer, NewRequest)
+        config.add_translation_dirs('colander:locale/')

cornice/schemas.py

@@ -94,11 +94,13 @@ def _validate_fields(location, data):
                         deserialized = attr.deserialize(serialized)
                 except Invalid as e:
                     # the struct is invalid
+                    translate = request.localizer.translate
+                    error_dict = e.asdict(translate=translate)
                     try:
                         request.errors.add(location, attr.name,
-                                           e.asdict()[attr.name])
+                                           error_dict[attr.name])
                     except KeyError:
-                        for k, v in e.asdict().items():
+                        for k, v in error_dict.items():
                             if k.startswith(attr.name):
                                 request.errors.add(location, k, v)
                 else:

cornice/tests/test_schemas.py

@@ -104,7 +104,7 @@ def test_colander_inheritance(self):
             inherited_schema = CorniceSchema.from_colander(InheritedSchema)
 
             self.assertEqual(len(base_schema.get_attributes()),
-                              len(inherited_schema.get_attributes()))
+                             len(inherited_schema.get_attributes()))
 
             foo_filter = lambda x: x.name == "foo"
             base_foo = list(filter(foo_filter,

cornice/tests/test_validation.py

@@ -1,3 +1,4 @@
+# -*- encoding: utf-8 -*-
 # This Source Code Form is subject to the terms of the Mozilla Public
 # License, v. 2.0. If a copy of the MPL was not distributed with this file,
 # You can obtain one at http://mozilla.org/MPL/2.0/.
@@ -362,3 +363,49 @@ def test_view_config_has_priority_over_global_config(self):
                             "hello,open,yeah",
                             headers={'content-type': 'text/dummy'})
         self.assertEqual(response.json['test'], 'succeeded')
+
+
+class TestErrorMessageTranslation(TestCase):
+
+    def post(self, settings={}, headers={}):
+        app = TestApp(main({}, **settings))
+        return app.post_json('/foobar?yeah=test', {
+            'foo': 'hello',
+            'bar': 'open',
+            'yeah': 'man',
+            'ipsum': 10,
+        }, status=400, headers=headers)
+
+    def assertErrorDescription(self, response, message):
+        error_description = response.json['errors'][0]['description']
+        self.assertEqual(error_description, message)
+
+    def test_accept_language_header(self):
+        response = self.post(
+            settings={'available_languages': 'fr en'},
+            headers={'Accept-Language': 'fr'})
+        self.assertErrorDescription(
+            response,
+            u'10 est plus grand que la valeur maximum autorisée (3)')
+
+    def test_default_language(self):
+        response = self.post(settings={
+            'available_languages': 'fr ja',
+            'pyramid.default_locale_name': 'ja',
+        })
+        self.assertErrorDescription(
+            response,
+            u'10 は最大値 3 を超過しています')
+
+    def test_default_language_fallback(self):
+        """Should fallback to default language if requested language is not
+        available"""
+        response = self.post(
+            settings={
+                'available_languages': 'ja en',
+                'pyramid.default_locale_name': 'ja',
+            },
+            headers={'Accept-Language': 'ru'})
+        self.assertErrorDescription(
+            response,
+            u'10 は最大値 3 を超過しています')

cornice/tests/validationapp.py

@@ -218,6 +218,6 @@ def includeme(config):
 
 
 def main(global_config, **settings):
-    config = Configurator(settings={})
+    config = Configurator(settings=settings)
     config.include(includeme)
     return CatchErrors(config.make_wsgi_app())