Allow suppressing context warnings (#28)

Fixes #27.

CHANGELOG.md

@@ -13,7 +13,7 @@ Possible log types:
 
 ## [Unreleased]
 
- - ...
+ - [changed] Allow suppressing context warnings (#27)
 
 ## [0.3.0] - 2018-03-03
 

README.rst

@@ -137,6 +137,27 @@ pass in the request through the context:
     serializer = EventSerializer(events, many=True, context={'request': request})
 
 
+Warnings
+--------
+
+If the request context does not have access to the request, a warning is
+emitted::
+
+   UserWarning: Context does not have access to request.
+
+First, make sure that you are passing the request to the serializer context (see
+"Usage" section).
+
+There are some cases (e.g. nested serializers) where you cannot get rid of the
+warning that way (see `issue 27 <https://github.com/dbrgn/drf-dynamic-fields/issues/27>`_).
+In that case, you can silence the warning through ``settings.py``:
+
+.. sourcecode:: python
+
+   DRF_DYNAMIC_FIELDS = {
+      'SUPPRESS_CONTEXT_WARNING': True,
+   }
+
 Scope
 -----
 

drf_dynamic_fields/__init__.py

@@ -3,6 +3,8 @@
 """
 import warnings
 
+from django.conf import settings
+
 
 class DynamicFieldsMixin(object):
     """
@@ -36,7 +38,10 @@ def fields(self):
         try:
             request = self.context['request']
         except KeyError:
-            warnings.warn('Context does not have access to request')
+            conf = getattr(settings, 'DRF_DYNAMIC_FIELDS', {})
+            if not conf.get('SUPPRESS_CONTEXT_WARNING', False) is True:
+                warnings.warn('Context does not have access to request. '
+                              'See README for more information.')
             return fields
 
         # NOTE: drf test framework builds a request object where the query