Add support for adding request contextual data to configuration objects.

This change adds a small namespace to configuraton objects that behaves
like a dictonary allowing objects to made available to e.g. request
handlers.

Such functionality it needed to support templates without restorting
to globals within the current system architecture; only congifuration
objects are already threaded through most of the places this would
need to be available with the correct semantics of an instance being
created wherever it is needed.

Author: albu-diku

mig/shared/configuration.py

@@ -761,6 +761,7 @@ def __init__(self, config_file, verbose=False, skip_log=False,
         self.default_page = None
         self.auth_logger_obj = None
         self.gdp_logger_obj = None
+        self._context = None
 
         configuration_options = copy.deepcopy(_CONFIGURATION_DEFAULTS)
 
@@ -772,6 +773,26 @@ def __init__(self, config_file, verbose=False, skip_log=False,
                                disable_auth_log=disable_auth_log,
                                _config_file=config_file)
 
+    def context(self, namespace=None):
+        """Retrieve the context or a previously registered namespace.
+        """
+
+        if self._context is None:
+            self._context = {}
+        if namespace is None:
+            return self._context
+        # allow the KeyError to escape if the registered namespace is missing
+        return self._context[namespace]
+
+    def context_set(self, value, namespace=None):
+        """Attach a value as named namespace within the active congifuration.
+        """
+        assert namespace is not None
+
+        context = self.context()
+        context[namespace] = value
+        return value
+
     def reload_config(self, verbose, skip_log=False, disable_auth_log=False,
                       _config_file=None):
         """Re-read and parse configuration file. Optional skip_log arg

tests/test_mig_shared_configuration.py

@@ -42,7 +42,7 @@ def _is_method(value):
 
 def _to_dict(obj):
     return {k: v for k, v in inspect.getmembers(obj)
-            if not (k.startswith('__') or _is_method(v))}
+            if not (k.startswith('_') or _is_method(v))}
 
 
 class MigSharedConfiguration(MigTestCase):