From 6beffc8d96f5753c45cf5168895ed954a853d147 Mon Sep 17 00:00:00 2001
From: Konsta Vesterinen <konsta.vesterinen@gmail.com>
Date: Tue, 23 Jul 2013 11:27:26 +0300
Subject: [PATCH] Added utility functions identity,
 is_auto_assigned_date_column and declarative_base

---
 CHANGES.rst                   |  6 ++++
 docs/index.rst                |  4 +++
 setup.py                      |  2 +-
 sqlalchemy_utils/__init__.py  |  2 +-
 sqlalchemy_utils/functions.py | 57 +++++++++++++++++++++++++++++++++++
 5 files changed, 69 insertions(+), 2 deletions(-)

diff --git a/CHANGES.rst b/CHANGES.rst
index b1f4e66..f300620 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -4,6 +4,12 @@ Changelog
 Here you can see the full list of changes between each SQLAlchemy-Utils release.
 
 
+0.15.1 (2013-07-22)
+^^^^^^^^^^^^^^^^^^^
+
+- Added utility functions declarative_base, identity and is_auto_assigned_date_column
+
+
 0.15.0 (2013-07-22)
 ^^^^^^^^^^^^^^^^^^^
 
diff --git a/docs/index.rst b/docs/index.rst
index 495ee72..fd69e30 100644
--- a/docs/index.rst
+++ b/docs/index.rst
@@ -206,6 +206,10 @@ API Documentation
 .. autofunction:: escape_like
 .. autofunction:: non_indexed_foreign_keys
 .. autofunction:: is_indexed_foreign_key
+.. autofunction:: identity
+.. autofunction:: is_auto_assigned_date_column
+.. autofunction:: declarative_base
+
 
 .. include:: ../CHANGES.rst
 
diff --git a/setup.py b/setup.py
index f18be5f..dfa4da2 100644
--- a/setup.py
+++ b/setup.py
@@ -24,7 +24,7 @@ class PyTest(Command):
 
 setup(
     name='SQLAlchemy-Utils',
-    version='0.15.0',
+    version='0.15.1',
     url='https://github.com/kvesteri/sqlalchemy-utils',
     license='BSD',
     author='Konsta Vesterinen',
diff --git a/sqlalchemy_utils/__init__.py b/sqlalchemy_utils/__init__.py
index 1bc660b..80a6f89 100644
--- a/sqlalchemy_utils/__init__.py
+++ b/sqlalchemy_utils/__init__.py
@@ -26,7 +26,7 @@ from .types import (
 )
 
 
-__version__ = '0.15.0'
+__version__ = '0.15.1'
 
 
 __all__ = (
diff --git a/sqlalchemy_utils/functions.py b/sqlalchemy_utils/functions.py
index a2e8eed..1446f8b 100644
--- a/sqlalchemy_utils/functions.py
+++ b/sqlalchemy_utils/functions.py
@@ -1,4 +1,5 @@
 from collections import defaultdict
+import sqlalchemy as sa
 from sqlalchemy.orm import defer
 from sqlalchemy.orm.mapper import Mapper
 from sqlalchemy.orm.query import _ColumnEntity
@@ -295,3 +296,59 @@ def is_indexed_foreign_key(constraint):
         if index_column_names == set(constraint.columns):
             return True
     return False
+
+
+def declarative_base(model):
+    """
+    Returns the declarative base for given model class.
+
+    :param model: SQLAlchemy declarative model
+    """
+    for parent in model.__bases__:
+        try:
+            parent.metadata
+            return declarative_base(parent)
+        except AttributeError:
+            pass
+    return model
+
+
+def is_auto_assigned_date_column(column):
+    """
+    Returns whether or not given SQLAlchemy Column object's is auto assigned
+    DateTime or Date.
+
+    :param column: SQLAlchemy Column object
+    """
+    return (
+        (
+            isinstance(column.type, sa.DateTime) or
+            isinstance(column.type, sa.Date)
+        )
+        and
+        (
+            column.default or
+            column.server_default or
+            column.onupdate or
+            column.server_onupdate
+        )
+    )
+
+
+def identity(obj):
+    """
+    Return the identity of given sqlalchemy declarative model instance as a
+    tuple. This differs from obj._sa_instance_state.identity in a way that it
+    always returns the identity even if object is still in transient state (
+    new object that is not yet persisted into database).
+
+    :param obj: SQLAlchemy declarative model object
+    """
+    id_ = []
+    for attr in obj._sa_class_manager.values():
+        prop = attr.property
+        if isinstance(prop, sa.orm.ColumnProperty):
+            column = prop.columns[0]
+            if column.primary_key:
+                id_.append(getattr(obj, column.name))
+    return tuple(id_)