diff -r 0037199881fb -r cf2304af0fab src/pyams_utils/data.py
--- a/src/pyams_utils/data.py	Wed Nov 20 19:26:23 2019 +0100
+++ b/src/pyams_utils/data.py	Fri Nov 22 18:51:37 2019 +0100
@@ -12,10 +12,10 @@
 
 """PyAMS_utils.data module
 
-The *IObjectData* interface is a generic interface which can be used to assign custom data to any object.
-This object data may be any object which can be serialized to JSON, and assigned to any HTML *data* attribute.
-It can typically be used to set a *data-ams-data* attribute to objects, which is afterwards converted to
-classic *data-* attributes by **MyAMS.js** framework.
+The *IObjectData* interface is a generic interface which can be used to assign custom data to any
+object. This object data may be any object which can be serialized to JSON, and assigned to any
+HTML *data* attribute. It can typically be used to set a *data-ams-data* attribute to objects,
+which is afterwards converted to classic *data-* attributes by **MyAMS.js** framework.
 
 For example, for a custom widget in a form::
 
@@ -34,8 +34,6 @@
     <div data-ams-colorpicker-position="top left">...</div>
 """
 
-__docformat__ = 'restructuredtext'
-
 import json
 
 from pyramid.interfaces import IRequest
@@ -47,6 +45,9 @@
 from pyams_utils.interfaces.tales import ITALESExtension
 
 
+__docformat__ = 'restructuredtext'
+
+
 @adapter_config(context=IObjectData, provides=IObjectDataRenderer)
 class ObjectDataRenderer(ContextAdapter):
     """Object data JSON renderer"""
@@ -57,12 +58,14 @@
         return json.dumps(data.object_data) if data is not None else None
 
 
-@adapter_config(name='object_data', context=(Interface, Interface, Interface), provides=ITALESExtension)
+@adapter_config(name='object_data', context=(Interface, Interface, Interface),
+                provides=ITALESExtension)
 class ObjectDataExtension(ContextRequestViewAdapter):
     """extension:object_data TALES extension
 
     This TALES extension is to be used in Chameleon templates to define a custom data attribute
-    which stores all object data (see :py:class:`pyams_utils.interfaces.data.IObjectData` interface), like this::
+    which stores all object data (see :py:class:`pyams_utils.interfaces.data.IObjectData`
+    interface), like this::
 
         <div tal:attributes="data-ams-data extension:object_data(context)">...</div>
     """
@@ -74,13 +77,16 @@
         renderer = IObjectDataRenderer(context, None)
         if renderer is not None:
             return renderer.get_object_data()
+        return None
 
 
-@adapter_config(name='request_data', context=(Interface, IRequest, Interface), provides=ITALESExtension)
+@adapter_config(name='request_data', context=(Interface, IRequest, Interface),
+                provides=ITALESExtension)
 class PyramidRequestDataExtension(ContextRequestViewAdapter):
     """extension:request_data TALES extension for Pyramid request
 
-    This TALES extension can be used to get a request data, previously stored in the request via an annotation.
+    This TALES extension can be used to get a request data, previously stored in the request via
+    an annotation.
     For example::
 
         <div tal:content="extension:request_data('my.annotation.key')">...</div>
@@ -91,11 +97,13 @@
         return self.request.annotations.get(params)
 
 
-@adapter_config(name='request_data', context=(Interface, IBrowserRequest, Interface), provides=ITALESExtension)
+@adapter_config(name='request_data', context=(Interface, IBrowserRequest, Interface),
+                provides=ITALESExtension)
 class BrowserRequestDataExtension(ContextRequestViewAdapter):
     """extension:request_data TALES extension for Zope browser request
 
-    This TALES extension can be used to get a request data, previously stored in the request via an annotation.
+    This TALES extension can be used to get a request data, previously stored in the request via
+    an annotation.
     For example::
 
         <div tal:content="extension:request_data('my.annotation.key')">...</div>