0.4.1 adding provider delegate

VERSION

@@ -1 +1 @@
-0.3.1
+0.4.1

examples/delegate.py

@@ -0,0 +1,52 @@
+"""
+Example of providers delegate.
+"""
+
+from objects import AbstractCatalog
+from objects.providers import Singleton
+from objects.providers import NewInstance
+from objects.injections import InitArg
+from objects.injections import Attribute
+
+
+import sqlite3
+
+
+# Some example classes.
+class ObjectA(object):
+    def __init__(self, db):
+        self.db = db
+
+
+class ObjectB(object):
+    def __init__(self, a_factory):
+        self.a_factory = a_factory
+
+
+# Catalog of objects providers.
+class Catalog(AbstractCatalog):
+    """
+    Objects catalog.
+    """
+
+    database = Singleton(sqlite3.Connection,
+                         InitArg('database', ':memory:'),
+                         Attribute('row_factory', sqlite3.Row))
+    """ :type: (objects.Provider) -> sqlite3.Connection """
+
+    object_a = NewInstance(ObjectA,
+                           InitArg('db', database))
+    """ :type: (objects.Provider) -> ObjectA """
+
+    object_b = Singleton(ObjectB,
+                         InitArg('a_factory', object_a.delegate()))
+    """ :type: (objects.Provider) -> ObjectB """
+
+
+# Catalog static provides.
+b = Catalog.object_b()
+a1, a2 = b.a_factory(), b.a_factory()
+
+# Some asserts.
+assert a1 is not a2
+assert a1.db is a2.db is Catalog.database()

objects/providers.py

@@ -32,6 +32,12 @@ class Provider(object):
         """
         self.__overridden_by__.append(provider)
 
+    def delegate(self):
+        """
+        Returns provider delegate.
+        """
+        return lambda *args, **kwargs: self.__call__(*args, **kwargs)
+
 
 def prepare_injections(injections):
     """