- Add a ``string`` renderer. This renderer converts a non-Response

  return value of any view callble into a string.  It is documented in
  the "Views" narrative chapter.

6 files changed, 74 insertions, 3 deletions

diff --git a/CHANGES.txt b/CHANGES.txt
index 8e48e544f..eeada7e49 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -1,6 +1,10 @@
 Next release
 ============
 
+- Add a ``string`` renderer.  This renderer converts a non-Response
+  return value of any view callble into a string.  It is documented in
+  the "Views" narrative chapter.
+
 - Give the ``route`` ZCML directive the ``view_attr`` and
   ``view_renderer`` parameters (bring up to speed with 1.1a3
   features).  These can also be spelled as ``attr`` and ``renderer``.
diff --git a/docs/narr/views.rst b/docs/narr/views.rst
index 74d95480c..b64fd2a4b 100644
--- a/docs/narr/views.rst
+++ b/docs/narr/views.rst
@@ -795,6 +795,39 @@ Several built-in "renderers" exist in :mod:`repoze.bfg`.  These
 renderers can be used in the ``renderer`` attribute of view
 configurations.
 
+``string``: String Renderer
+~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+The ``string`` renderer is a renderer which renders a view callable
+result to a string.  If a view callable returns a non-Response object,
+and the ``string`` renderer is associated in that view's
+configuration, the result will be to run the object through the Python
+``str`` function to generate a string.  Note that if a Unicode object
+is returned, it is not ``str()`` -ified.
+
+Here's an example of a view that returns a dictionary.  If the
+``string`` renderer is specified in the configuration for this view,
+the view will render the returned dictionary to the ``str()``
+representation of the dictionary:
+
+.. code-block:: python
+   :linenos:
+
+   from webob import Response
+   from repoze.bfg.view import bfg_view
+
+   @bfg_view(renderer='string')
+   def hello_world(context, request):
+       return {'content':'Hello!'}
+
+The body of the response returned by such a view will be a string
+representing the ``str()`` serialization of the return value:
+
+.. code-block: python
+   :linenos:
+
+   {'content': 'Hello!'}
+
 ``json``: JSON Renderer
 ~~~~~~~~~~~~~~~~~~~~~~~
 
@@ -802,7 +835,7 @@ The ``json`` renderer is a renderer which renders view callable
 results to :term:`JSON`.  If a view callable returns a non-Response
 object it is called.  It passes the return value through the
 ``simplejson.dumps`` function, and wraps the result in a response
-object.  For example:
+object.
 
 Here's an example of a view that returns a dictionary.  If the
 ``json`` renderer is specified in the configuration for this view, the
diff --git a/repoze/bfg/includes/configure.zcml b/repoze/bfg/includes/configure.zcml
index 37cd4d75a..60119b2c9 100644
--- a/repoze/bfg/includes/configure.zcml
+++ b/repoze/bfg/includes/configure.zcml
@@ -33,4 +33,9 @@
      name="json"
      />
 
+  <renderer
+     factory="repoze.bfg.renderers.string_renderer_factory"
+     name="string"
+     />
+
 </configure>
diff --git a/repoze/bfg/renderers.py b/repoze/bfg/renderers.py
index 503131400..c5aed2906 100644
--- a/repoze/bfg/renderers.py
+++ b/repoze/bfg/renderers.py
@@ -22,6 +22,13 @@ def json_renderer_factory(name):
         return json.dumps(value)
     return _render
 
+def string_renderer_factory(name):
+    def _render(value):
+        if not isinstance(value, basestring):
+            value = str(value)
+        return value
+    return _render
+
 # utility functions
 
 def template_renderer_factory(path, impl, level=3):
diff --git a/repoze/bfg/router.py b/repoze/bfg/router.py
index d9502a435..e8497331b 100644
--- a/repoze/bfg/router.py
+++ b/repoze/bfg/router.py
@@ -114,8 +114,8 @@ class Router(object):
                     return response.app_iter
                 except AttributeError:
                     raise ValueError(
-                        'Non-response object returned from view %s: %r' %
-                        (view_name, response))
+                        'Non-response object returned from view named %s '
+                        '(and no renderer): %r' % (view_name, response))
 
             provides = map(providedBy, (context, request))
             view_callable = registry.adapters.lookup(
diff --git a/repoze/bfg/tests/test_renderers.py b/repoze/bfg/tests/test_renderers.py
index 6e33f4ce5..d1acc0285 100644
--- a/repoze/bfg/tests/test_renderers.py
+++ b/repoze/bfg/tests/test_renderers.py
@@ -178,7 +178,29 @@ class Test_json_renderer_factory(unittest.TestCase):
         renderer = self._callFUT(None)
         result = renderer({'a':1})
         self.assertEqual(result, '{"a": 1}')
+
+class Test_string_renderer_factory(unittest.TestCase):
+    def _callFUT(self, name):
+        from repoze.bfg.renderers import string_renderer_factory
+        return string_renderer_factory(name)
+
+    def test_it_unicode(self):
+        renderer = self._callFUT(None)
+        value = unicode('La Pe\xc3\xb1a', 'utf-8')
+        result = renderer(value)
+        self.assertEqual(result, value)
                           
+    def test_it_str(self):
+        renderer = self._callFUT(None)
+        value = 'La Pe\xc3\xb1a'
+        result = renderer(value)
+        self.assertEqual(result, value)
+
+    def test_it_other(self):
+        renderer = self._callFUT(None)
+        value = None
+        result = renderer(value)
+        self.assertEqual(result, 'None')
 
 class DummyFactory:
     def __init__(self, renderer):