Update external dependency provider docs

dependency_injector/providers/base.py

@@ -295,6 +295,7 @@ class ExternalDependency(Provider):
             raise Error('ExternalDependency provider expects to get class, ' +
                         'got {0} instead'.format(str(instance_of)))
         self.instance_of = instance_of
+        self.provide = self.__call__
         super(ExternalDependency, self).__init__()
 
     def __call__(self, *args, **kwargs):

docs/providers/external_dependency.rst

@@ -28,11 +28,11 @@ Example:
 
 .. note::
 
-    Class ``UserService`` is a part of some library. ``UserService`` has
+    Class ``UsersService`` is a part of some library. ``UsersService`` has
     dependency on database connection, which can be satisfied with any
     DBAPI 2.0 database connection. Being a self-sufficient library,
-    ``UserService`` doesn't hardcode any kind of database management logic.
-    Instead of this, ``UserService`` has external dependency, that has to
+    ``UsersService`` doesn't hardcode any kind of database management logic.
+    Instead of this, ``UsersService`` has external dependency, that has to
     be satisfied by cleint's code, out of library's scope.
 
 .. image:: /images/providers/external_dependency.png

examples/providers/external_dependency.py

@@ -2,13 +2,14 @@
 
 import sqlite3
 import contextlib
+
 import dependency_injector.providers as providers
 
 
-class UserService(object):
-    """Example class UserService.
+class UsersService(object):
+    """Example class UsersService.
 
-    UserService has dependency on DBAPI 2.0 database connection.
+    UsersService has dependency on DBAPI 2.0 database connection.
     """
 
     def __init__(self, database):
@@ -43,9 +44,9 @@ class UserService(object):
             return cursor.fetchone()
 
 
-# Database and UserService providers:
+# Database and UsersService providers:
 database = providers.ExternalDependency(instance_of=sqlite3.dbapi2.Connection)
-users_service_factory = providers.Factory(UserService,
+users_service_factory = providers.Factory(UsersService,
                                           database=database)
 
 # Out of library's scope.
@@ -57,10 +58,10 @@ database.provided_by(providers.Singleton(sqlite3.dbapi2.Connection,
                                          detect_types=True,
                                          isolation_level='EXCLUSIVE'))
 
-# Creating UserService instance:
+# Creating UsersService instance:
 users_service = users_service_factory()
 
-# Initializing UserService database:
+# Initializing UsersService database:
 users_service.init_database()
 
 # Creating test user and retrieving full information about him: