Add CurrencyType class

docs/data_types.rst

@@ -38,6 +38,15 @@ CountryType
 
 .. autoclass:: CountryType
 
+
+CurrencyType
+^^^^^^^^^^^^
+
+.. module:: sqlalchemy_utils.types.currency
+
+.. autoclass:: CurrencyType
+
+
 EncryptedType
 ^^^^^^^^^^^^^
 

sqlalchemy_utils/__init__.py

@@ -64,6 +64,7 @@ from .types import (  # noqa
     ColorType,
     Country,
     CountryType,
+    CurrencyType,
     DateRangeType,
     DateTimeRangeType,
     EmailType,

sqlalchemy_utils/types/__init__.py

@@ -6,6 +6,7 @@ from .arrow import ArrowType
 from .choice import Choice, ChoiceType
 from .color import ColorType
 from .country import Country, CountryType
+from .currency import CurrencyType
 from .email import EmailType
 from .encrypted import EncryptedType
 from .ip_address import IPAddressType
@@ -33,6 +34,7 @@ __all__ = (
     ColorType,
     Country,
     CountryType,
+    CurrencyType,
     DateRangeType,
     DateTimeRangeType,
     EmailType,

sqlalchemy_utils/types/currency.py

@@ -0,0 +1,66 @@
+import six
+from sqlalchemy import types
+
+from sqlalchemy_utils.primitives import Currency
+
+from .scalar_coercible import ScalarCoercible
+
+
+class CurrencyType(types.TypeDecorator, ScalarCoercible):
+    """
+    Changes Currency objects to a string representation on the way in and
+    changes them back to Currency objects on the way out.
+
+    In order to use CurrencyType you need to install Babel_ first.
+
+    .. _Babel: http://babel.pocoo.org/
+
+    ::
+
+
+        from sqlalchemy_utils import CurrencyType, Currency
+
+
+        class User(Base):
+            __tablename__ = 'user'
+            id = sa.Column(sa.Integer, autoincrement=True)
+            name = sa.Column(sa.Unicode(255))
+            currency = sa.Column(CurrencyType)
+
+
+        user = User()
+        user.currency = Currency('USD')
+        session.add(user)
+        session.commit()
+
+        user.currency  # Currency('USD')
+        user.currency.name  # US Dollar
+
+        str(user.currency)  # US Dollar
+        user.currency.symbol  # $
+
+
+
+    CurrencyType is scalar coercible::
+
+
+        user.currency = 'US'
+        user.currency  # Currency('US')
+    """
+    impl = types.String(3)
+    python_type = Currency
+
+    def process_bind_param(self, value, dialect):
+        if isinstance(value, Currency):
+            return value.code
+        elif isinstance(value, six.string_types):
+            return value
+
+    def process_result_value(self, value, dialect):
+        if value is not None:
+            return Currency(value)
+
+    def _coerce(self, value):
+        if value is not None and not isinstance(value, Currency):
+            return Currency(value)
+        return value

tests/types/test_currency.py

@@ -0,0 +1,38 @@
+# -*- coding: utf-8 -*-
+import sqlalchemy as sa
+from babel import Locale
+
+from sqlalchemy_utils import Currency, CurrencyType, i18n
+from tests import TestCase
+
+
+class TestCurrencyType(TestCase):
+    def setup_method(self, method):
+        TestCase.setup_method(self, method)
+        i18n.get_locale = lambda: Locale('en')
+
+    def create_models(self):
+        class User(self.Base):
+            __tablename__ = 'user'
+            id = sa.Column(sa.Integer, primary_key=True)
+            currency = sa.Column(CurrencyType)
+
+            def __repr__(self):
+                return 'User(%r)' % self.id
+
+        self.User = User
+
+    def test_parameter_processing(self):
+        user = self.User(
+            currency=Currency('USD')
+        )
+
+        self.session.add(user)
+        self.session.commit()
+
+        user = self.session.query(self.User).first()
+        assert user.currency.name == u'US Dollar'
+
+    def test_scalar_attributes_get_coerced_to_objects(self):
+        user = self.User(currency='USD')
+        assert isinstance(user.currency, Currency)