stop relying on ujson (fix #589, #587, #507)

CHANGELOG.rst

@@ -6,6 +6,8 @@ Changelog
 Current
 -------
 
+- **Behavior**:
+    * ``ujson`` is not the default json serializer anymore. A new configuration option is available instead: ``RESTPLUS_JSON_SERIALIZER`` (:issue:`507`, :issue:`587`, :issue:`589`, :pr:`637`)
 - Add new `Wildcard` fields (:pr:`255`)
 - Fix ABC deprecation warnings (:pr:`580`)
 - Fix `@api.expect(..., validate=False)` decorators for an :class:`Api` where `validate=True` is set on the constructor (:issue:`609`, :pr:`610`)

doc/quickstart.rst

@@ -308,6 +308,77 @@ parameter to some classes or function to force order preservation:
 - globally on :class:`Namespace`: ``ns = Namespace(ordered=True)``
 - locally on :func:`marshal`: ``return marshal(data, fields, ordered=True)``
 
+Configuration
+-------------
+
+The following configuration options exist for Flask-RESTPlus:
+
+============================ =============== ==================================
+    OPTION                    DEFAULT VALUE             DESCRIPTION
+============================ =============== ==================================
+``BUNDLE_ERRORS``               ``False``     Bundle all the validation errors
+                                              instead of returning only the
+                                              first one encountered.
+                                              See the `Error Handling
+                                              <parsing.html#error-handling>`__
+                                              section of the documentation for
+                                              details.
+``RESTPLUS_VALIDATE``           ``False``     Whether to enforce payload
+                                              validation by default when using
+                                              the ``@api.expect()`` decorator.
+                                              See the `@api.expect()
+                                              <swagger.html#the-api-expect-decorator>`__
+                                              documentation for details.
+``RESTPLUS_MASK_HEADER``      ``X-Fields``    Choose the name of the *Header*
+                                              that will contain the masks to
+                                              apply to your answer.
+                                              See the `Fields masks <mask.html>`__
+                                              documentation for details.
+``RESTPLUS_MASK_SWAGGER``       ``True``      Whether to enable the mask
+                                              documentation in your swagger or
+                                              not.
+                                              See the `mask usage
+                                              <mask.html#usage>`__ documentation
+                                              for details.
+``RESTPLUS_JSON``                ``{}``       Dictionary of options to pass to
+                                              the json *serializer* (by default
+                                              ``json.dumps``).
+``RESTPLUS_JSON_SERIALIZER``    ``None``      Here you can choose your
+                                              own/preferred json *serializer*.
+                                              You can either specify the name
+                                              of the module (example: ``ujson``)
+                                              or you can give the full name of
+                                              your *serializer* (example:
+                                              ``ujson.dumps``).
+
+                                              .. note::
+                                                  If you only specify the module
+                                                  name the default Flask-RESTPlus
+                                                  behavior is to import its
+                                                  ``dumps`` method.
+
+
+                                              .. note::
+                                                  Flask-RESTPlus will always
+                                                  fallback to the default
+                                                  ``json.dumps`` *serializer*
+                                                  if it cannot manage to import
+                                                  the one you configured.
+                                                  In such case, a
+                                                  ``UserWarning`` will be
+                                                  raised.
+
+
+                                              .. warning::
+                                                  We only officially support
+                                                  python's builtin
+                                                  ``json.dumps``.
+                                                  Please keep in mind some
+                                                  serializers may behave
+                                                  differently depending on the
+                                                  input types (floats, dates,
+                                                  etc.).
+============================ =============== ==================================
 
 Full example
 ------------

flask_restplus/api.py

@@ -32,7 +32,7 @@
 from .postman import PostmanCollectionV1
 from .resource import Resource
 from .swagger import Swagger
-from .utils import default_id, camel_to_dash, unpack
+from .utils import default_id, camel_to_dash, preload_serializer, unpack
 from .representations import output_json
 from ._http import HTTPStatus
 
@@ -209,6 +209,7 @@ def _init_app(self, app):
         self._validate = self._validate if self._validate is not None else app.config.get('RESTPLUS_VALIDATE', False)
         app.config.setdefault('RESTPLUS_MASK_HEADER', 'X-Fields')
         app.config.setdefault('RESTPLUS_MASK_SWAGGER', True)
+        preload_serializer(app)
 
     def __getattr__(self, name):
         try:

flask_restplus/representations.py

@@ -1,18 +1,18 @@
 # -*- coding: utf-8 -*-
 from __future__ import unicode_literals, absolute_import
 
-try:
-    from ujson import dumps
-except ImportError:
-    from json import dumps
-
 from flask import make_response, current_app
 
+from .utils import preload_serializer
+
 
 def output_json(data, code, headers=None):
     '''Makes a Flask response with a JSON encoded body'''
-
     settings = current_app.config.get('RESTPLUS_JSON', {})
+    serializer = current_app.config.get('RESTPLUS_CACHED_SERIALIZER')
+    if serializer is None:
+        preload_serializer(current_app)
+        serializer = current_app.config.get('RESTPLUS_CACHED_SERIALIZER')
 
     # If we're in debug mode, and the indent is not set, we set it to a
     # reasonable value here.  Note that this won't override any existing value
@@ -22,7 +22,7 @@ def output_json(data, code, headers=None):
 
     # always end the json dumps with a new line
     # see https://github.com/mitsuhiko/flask/pull/1262
-    dumped = dumps(data, **settings) + "\n"
+    dumped = serializer(data, **settings) + "\n"
 
     resp = make_response(dumped, code)
     resp.headers.extend(headers or {})

flask_restplus/utils.py

@@ -2,9 +2,12 @@
 from __future__ import unicode_literals
 
 import re
+import importlib
+import warnings
 
 from collections import OrderedDict
 from copy import deepcopy
+from json import dumps
 from six import iteritems
 
 from ._http import HTTPStatus
@@ -14,7 +17,51 @@
 ALL_CAP_RE = re.compile('([a-z0-9])([A-Z])')
 
 
-__all__ = ('merge', 'camel_to_dash', 'default_id', 'not_none', 'not_none_sorted', 'unpack')
+__all__ = ('preload_serializer', 'importer', 'merge', 'camel_to_dash', 'default_id',
+           'not_none', 'not_none_sorted', 'unpack')
+
+
+def preload_serializer(app):
+    '''
+    Preload the json serializer for the given ``app``.
+
+    :param flask.Flask app: The flask application object
+    '''
+    custom_serializer = app.config.get('RESTPLUS_JSON_SERIALIZER', None)
+    serializer = None
+
+    # If the user wants to use a custom serializer, let it be
+    if custom_serializer:
+        try:
+            serializer = importer(custom_serializer, 'dumps')
+        except ImportError:
+            if '.' in custom_serializer:
+                mod, func = custom_serializer.rsplit('.', 1)
+                try:
+                    serializer = importer(mod, func)
+                except ImportError:
+                    warnings.warn("Unable to load custom serializer '{}', falling back to "
+                                  "'json.dumps'".format(custom_serializer),
+                                  UserWarning)
+
+    # fallback, no serializer found so far, use the default one
+    if serializer is None:
+        serializer = dumps
+    app.config['RESTPLUS_CACHED_SERIALIZER'] = serializer
+
+
+def importer(mod_name, obj_name, default=None):
+    '''
+    Import the given ``obj_name`` from the given ``mod_name``.
+
+    :param str mod_name: Module from which to import the ``obj_name``
+    :param str obj_name: Object to import from ``mod_name``
+    :param object default: Default object to return
+
+    :return: Imported object
+    '''
+    imported = importlib.import_module(mod_name)
+    return getattr(imported, obj_name, default)
 
 
 def merge(first, second):

requirements/test.pip

@@ -9,3 +9,4 @@ pytest-mock==1.6.3
 pytest-profiling==1.2.11
 pytest-sugar==0.9.0
 tzlocal
+ujson

tests/test_representations.py

@@ -0,0 +1,46 @@
+import pytest
+
+import flask_restplus.representations as rep
+from flask_restplus.utils import preload_serializer
+
+from json import dumps, loads
+from ujson import dumps as udumps, loads as uloads
+
+payload = {
+    'id': 1,
+    'name': 'toto',
+    'address': 'test',
+}
+
+
+def test_representations_serialization_output_correct(app):
+    print(app.config)
+    r = rep.output_json(payload, 200)
+    assert loads(r.get_data(True)) == loads(dumps(payload))
+
+
+def test_config_custom_serializer_is_module(app, api):
+    # enforce a custom serializer
+    app.config['RESTPLUS_JSON_SERIALIZER'] = 'ujson'
+    # now reset serializer
+    preload_serializer(app)
+    r2 = rep.output_json(payload, 200)
+    assert uloads(r2.get_data(True)) == uloads(udumps(payload))
+    assert app.config.get('RESTPLUS_CACHED_SERIALIZER') == udumps
+
+
+def test_config_custom_serializer_is_function(app, api):
+    # test other config syntax
+    app.config['RESTPLUS_JSON_SERIALIZER'] = 'ujson.dumps'
+    preload_serializer(app)
+    rep.output_json(payload, 200)
+    assert app.config.get('RESTPLUS_CACHED_SERIALIZER') == udumps
+
+
+def test_config_custom_serializer_fallback(app, api):
+    # test fallback
+    app.config['RESTPLUS_JSON_SERIALIZER'] = 'ujson.lol.dumps'
+    with pytest.warns(UserWarning):
+        preload_serializer(app)
+    rep.output_json(payload, 200)
+    assert app.config.get('RESTPLUS_CACHED_SERIALIZER') == dumps