add a respones arg to render_to_response

2 files changed, 34 insertions, 6 deletions

diff --git a/pyramid/renderers.py b/pyramid/renderers.py
index c4ea22429..088d451bb 100644
--- a/pyramid/renderers.py
+++ b/pyramid/renderers.py
@@ -79,7 +79,11 @@ def render(renderer_name, value, request=None, package=None):
 
     return result
 
-def render_to_response(renderer_name, value, request=None, package=None):
+def render_to_response(renderer_name,
+                       value,
+                       request=None,
+                       package=None,
+                       response=None):
     """ Using the renderer ``renderer_name`` (a template
     or a static renderer), render the value (or set of values) using
     the result of the renderer's ``__call__`` method (usually a string
@@ -112,12 +116,14 @@ def render_to_response(renderer_name, value, request=None, package=None):
     with the most correct 'system' values (``request`` and ``context``
     in particular). Keep in mind that any changes made to ``request.response``
     prior to calling this function will not be reflected in the resulting
-    response object. A new response object will be created for each call.
+    response object. A new response object will be created for each call
+    unless one is passed as the ``response`` argument.
 
     .. versionchanged:: 1.6
        In previous versions, any changes made to ``request.response`` outside
        of this function call would affect the returned response. This is no
-       longer the case.
+       longer the case. If you wish to send in a pre-initialized response
+       then you may pass one in the ``response`` argument.
 
     """
     try:
@@ -130,6 +136,8 @@ def render_to_response(renderer_name, value, request=None, package=None):
                             registry=registry)
 
     with temporary_response(request):
+        if response is not None:
+            request.response = response
         result = helper.render_to_response(value, None, request=request)
 
     return result
diff --git a/pyramid/tests/test_renderers.py b/pyramid/tests/test_renderers.py
index 31e9d14f8..ed6344a40 100644
--- a/pyramid/tests/test_renderers.py
+++ b/pyramid/tests/test_renderers.py
@@ -517,10 +517,11 @@ class Test_render_to_response(unittest.TestCase):
     def tearDown(self):
         testing.tearDown()
 
-    def _callFUT(self, renderer_name, value, request=None, package=None):
+    def _callFUT(self, renderer_name, value, request=None, package=None,
+                 response=None):
         from pyramid.renderers import render_to_response
         return render_to_response(renderer_name, value, request=request,
-                                  package=package)
+                                  package=package, response=response)
 
     def test_it_no_request(self):
         renderer = self.config.testing_add_renderer(
@@ -579,6 +580,18 @@ class Test_render_to_response(unittest.TestCase):
         self.assertEqual(result.body, b'{"a": 1}')
         self.assertFalse('response' in request.__dict__)
 
+    def test_custom_response_object(self):
+        class DummyRequestWithClassResponse(object):
+            pass
+        request = DummyRequestWithClassResponse()
+        response = DummyResponse()
+        # use a json renderer, which will mutate the response
+        result = self._callFUT('json', dict(a=1), request=request,
+                               response=response)
+        self.assertTrue(result is response)
+        self.assertEqual(result.body, b'{"a": 1}')
+        self.assertFalse('response' in request.__dict__)
+
 class Test_get_renderer(unittest.TestCase):
     def setUp(self):
         self.config = testing.setUp()
@@ -639,7 +652,14 @@ class Dummy:
 
 class DummyResponse:
     status = '200 OK'
+    default_content_type = 'text/html'
+    content_type = default_content_type
     headerlist = ()
     app_iter = ()
-    body = ''
+    body = b''
+
+    # compat for renderer that will set unicode on py3
+    def _set_text(self, val): # pragma: no cover
+        self.body = val.encode('utf8')
+    text = property(fset=_set_text)