let the user choose a custom json serializer through the RESTPLUS_JSON_SERIALIZER config option

Author: ziirish

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 +308,75 @@ 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
+                                                  silently fallback to the
+                                                  default ``json.dumps``
+                                                  *serializer* if it cannot
+                                                  manage to import the one
+                                                  you configured.
+
+
+                                              .. 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/representations.py

@@ -1,15 +1,44 @@
 # -*- coding: utf-8 -*-
 from __future__ import unicode_literals, absolute_import
 
+import importlib
+
 from json import dumps
 
 from flask import make_response, current_app
 
+DEFAULT_SERIALIZER = 'dumps'
+serializer = None
+
+
+def _importer(mod_name, func_name=DEFAULT_SERIALIZER, default=dumps):
+    imported = importlib.import_module(mod_name)
+    return getattr(imported, func_name, default)
+
 
 def output_json(data, code, headers=None):
     '''Makes a Flask response with a JSON encoded body'''
 
+    global serializer
+
     settings = current_app.config.get('RESTPLUS_JSON', {})
+    custom_serializer = current_app.config.get('RESTPLUS_JSON_SERIALIZER', None)
+
+    # If the user wants to use a custom serializer, let it be
+    if serializer is None and custom_serializer:
+        try:
+            serializer = _importer(custom_serializer)
+        except ImportError:
+            if '.' in custom_serializer:
+                mod, func = custom_serializer.rsplit('.', 1)
+                try:
+                    serializer = _importer(mod, func)
+                except ImportError:
+                    pass
+
+    # fallback, no serializer found so far, use the default one
+    if serializer is None:
+        serializer = dumps
 
     # 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
@@ -19,7 +48,7 @@ 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 {})

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 +1,41 @@
+import flask_restplus.representations as rep
+
+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):
+    r = rep.output_json(payload, 200)
+    assert loads(r.get_data(True)) == loads(dumps(payload))
+
+
+def test_config_custom_serializer_is_module(app):
+    # now reset serializer
+    rep.serializer = None
+    # then enforce a custom serializer
+    app.config['RESTPLUS_JSON_SERIALIZER'] = 'ujson'
+    r2 = rep.output_json(payload, 200)
+    assert uloads(r2.get_data(True)) == uloads(udumps(payload))
+    assert rep.serializer == udumps
+
+
+def test_config_custom_serializer_is_function(app):
+    # test other config syntax
+    rep.serializer = None
+    app.config['RESTPLUS_JSON_SERIALIZER'] = 'ujson.dumps'
+    rep.output_json(payload, 200)
+    assert rep.serializer == udumps
+
+
+def test_config_custom_serializer_fallback(app):
+    # test fallback
+    rep.serializer = None
+    app.config['RESTPLUS_JSON_SERIALIZER'] = 'ujson.lol.dumps'
+    rep.output_json(payload, 200)
+    assert rep.serializer == dumps