Improving of Providers extending

objects/providers.py

@@ -23,6 +23,17 @@ class Provider(object):
 
     def __call__(self, *args, **kwargs):
         """Return provided instance."""
+        if self.overridden:
+            return self.last_overriding(*args, **kwargs)
+        return self.__provide__(*args, **kwargs)
+
+    def __provide__(self, *args, **kwargs):
+        """Providing strategy implementation.
+
+        Abstract protected method that implements providing strategy of
+        particular provider. Current method is called every time when not
+        overridden provider is called. Need to be overridden in subclasses.
+        """
         raise NotImplementedError()
 
     def delegate(self):
@@ -64,7 +75,7 @@ class Delegate(Provider):
         self.delegated = ensure_is_provider(delegated)
         super(Delegate, self).__init__()
 
-    def __call__(self):
+    def __provide__(self, *args, **kwargs):
         """Return provided instance."""
         return self.delegated
 
@@ -95,11 +106,8 @@ class Factory(Provider):
                               if is_method_injection(injection)))
         super(Factory, self).__init__()
 
-    def __call__(self, *args, **kwargs):
+    def __provide__(self, *args, **kwargs):
         """Return provided instance."""
-        if self.overridden:
-            return self.last_overriding(*args, **kwargs)
-
         init_kwargs = dict(((injection.name, injection.value)
                             for injection in self.kwargs))
         init_kwargs.update(kwargs)
@@ -139,7 +147,7 @@ class Singleton(Provider):
         self.factory = Factory(*args, **kwargs)
         super(Singleton, self).__init__()
 
-    def __call__(self, *args, **kwargs):
+    def __provide__(self, *args, **kwargs):
         """Return provided instance."""
         if not self.instance:
             self.instance = self.factory(*args, **kwargs)
@@ -197,10 +205,8 @@ class _StaticProvider(Provider):
         self.provides = provides
         super(_StaticProvider, self).__init__()
 
-    def __call__(self):
+    def __provide__(self, *args, **kwargs):
         """Return provided instance."""
-        if self.overridden:
-            return self.last_overriding()
         return self.provides
 
 
@@ -244,11 +250,8 @@ class Callable(Provider):
                                  if is_kwarg_injection(injection)))
         super(Callable, self).__init__()
 
-    def __call__(self, *args, **kwargs):
+    def __provide__(self, *args, **kwargs):
         """Return provided instance."""
-        if self.overridden:
-            return self.last_overriding()
-
         injections = dict(((injection.name, injection.value)
                            for injection in self.injections))
         injections.update(kwargs)
@@ -274,7 +277,7 @@ class Config(Provider):
         self.value = value
         super(Config, self).__init__()
 
-    def __call__(self, paths=None):
+    def __provide__(self, paths=None):
         """Return provided instance."""
         value = self.value
         if paths:
@@ -311,7 +314,7 @@ class _ChildConfig(Provider):
         self.root_config = root_config
         super(_ChildConfig, self).__init__()
 
-    def __call__(self, *args, **kwargs):
+    def __provide__(self, *args, **kwargs):
         """Return provided instance."""
         return self.root_config(self.parents)