Option to disable content-type guessing by URL

Add a new option to disable content-type guessing
based on the extension of the URL.

Change-Id: I5bea41fcc1011cfb19255cc0333924034007a645
Signed-off-by: Doug Hellmann <doug.hellmann@dreamhost.com>

pecan/core.py

@@ -177,11 +177,15 @@ class Pecan(object):
                                 namespace automatically.
     :param force_canonical: A boolean indicating if this project should
                             require canonical URLs.
+    :param guess_content_type_from_ext: A boolean indicating if this project
+                            should use the extension in the URL for guessing
+                            the content type to return.
     '''
 
     def __init__(self, root, default_renderer='mako',
                  template_path='templates', hooks=[], custom_renderers={},
-                 extra_template_vars={}, force_canonical=True):
+                 extra_template_vars={}, force_canonical=True,
+                 guess_content_type_from_ext=True):
 
         if isinstance(root, basestring):
             root = self.__translate_root__(root)
@@ -192,6 +196,7 @@ class Pecan(object):
         self.hooks = hooks
         self.template_path = template_path
         self.force_canonical = force_canonical
+        self.guess_content_type_from_ext = guess_content_type_from_ext
 
     def __translate_root__(self, item):
         '''
@@ -370,7 +375,9 @@ class Pecan(object):
         request.pecan['extension'] = None
 
         # attempt to guess the content type based on the file extension
-        if not request.pecan['content_type'] and '.' in path.split('/')[-1]:
+        if self.guess_content_type_from_ext \
+                and not request.pecan['content_type'] \
+                and '.' in path.split('/')[-1]:
             new_path, extension = splitext(path)
 
             # preface with a letter to ensure compat for 2.5

pecan/scaffolds/base/+package+/app.py_tmpl

@@ -12,5 +12,9 @@ def setup_app(config):
         template_path=config.app.template_path,
         logging=getattr(config, 'logging', {}),
         debug=getattr(config.app, 'debug', False),
-        force_canonical=getattr(config.app, 'force_canonical', True)
+        force_canonical=getattr(config.app, 'force_canonical', True),
+        guess_content_type_from_ext=getattr(
+            config.app,
+            'guess_content_type_from_ext',
+            True),
     )

pecan/tests/test_base.py

@@ -925,6 +925,21 @@ class TestFileTypeExtensions(unittest.TestCase):
         assert r.status_int == 200
         assert r.body == 'SOME VALUE'
 
+    def test_guessing_disabled(self):
+        class RootController(object):
+            @expose(content_type=None)
+            def _default(self, *args):
+                assert 'index.html' in args
+                assert request.pecan['extension'] is None
+                return 'SOME VALUE'
+
+        app = TestApp(Pecan(RootController(),
+                            guess_content_type_from_ext=False))
+
+        r = app.get('/index.html')
+        assert r.status_int == 200
+        assert r.body == 'SOME VALUE'
+
 
 class TestContentTypeByAcceptHeaders(unittest.TestCase):