Added docs for ChoiceType

CHANGES.rst

@@ -4,6 +4,12 @@ Changelog
 Here you can see the full list of changes between each SQLAlchemy-Utils release.
 
 
+0.19.0 (2013-10-24)
+^^^^^^^^^^^^^^^^^^^
+
+- Added ChoiceType
+
+
 0.18.0 (2013-10-24)
 ^^^^^^^^^^^^^^^^^^^
 

docs/index.rst

@@ -37,9 +37,9 @@ Example
 
     class Document(Base):
         __tablename__ = 'player'
-        id = db.Column(db.Integer, autoincrement=True)
-        name = db.Column(db.Unicode(50))
-        background_color = db.Column(ColorType)
+        id = sa.Column(sa.Integer, autoincrement=True)
+        name = sa.Column(sa.Unicode(50))
+        background_color = sa.Column(ColorType)
 
 
     document = Document()
@@ -55,6 +55,58 @@ Data types
 SQLAlchemy-Utils provides various new data types for SQLAlchemy.
 
 
+ChoiceType
+^^^^^^^^^^
+
+ChoiceType offers way of having fixed set of choices for given column. Columns with ChoiceTypes are automatically coerced to Choice objects.
+
+
+::
+
+
+    class User(self.Base):
+        TYPES = [
+            (u'admin', u'Admin'),
+            (u'regular-user', u'Regular user')
+        ]
+
+        __tablename__ = 'user'
+        id = sa.Column(sa.Integer, primary_key=True)
+        name = sa.Column
+        type = sa.Column(ChoiceType(TYPES))
+
+
+    user = User(type=u'admin')
+    user.type  # Choice(type='admin', value=u'Admin')
+
+
+
+ChoiceType is very useful when the rendered values change based on user's locale:
+
+::
+
+    from babel import lazy_gettext as _
+
+
+    class User(self.Base):
+        TYPES = [
+            (u'admin', _(u'Admin')),
+            (u'regular-user', _(u'Regular user'))
+        ]
+
+        __tablename__ = 'user'
+        id = sa.Column(sa.Integer, primary_key=True)
+        name = sa.Column
+        type = sa.Column(ChoiceType(TYPES))
+
+
+    user = User(type=u'admin')
+    user.type  # Choice(type='admin', value=u'Admin')
+
+
+
+
+
 ColorType
 ^^^^^^^^^
 
@@ -70,9 +122,9 @@ ColorType saves Color objects as strings on the way in and converts them back to
 
     class Document(Base):
         __tablename__ = 'document'
-        id = db.Column(db.Integer, autoincrement=True)
-        name = db.Column(db.Unicode(50))
-        background_color = db.Column(ColorType)
+        id = sa.Column(sa.Integer, autoincrement=True)
+        name = sa.Column(sa.Unicode(50))
+        background_color = sa.Column(ColorType)
 
 
     document = Document()
@@ -110,9 +162,9 @@ In order to use LocaleType you need to install Babel_ first.
 
     class User(Base):
         __tablename__ = 'user'
-        id = db.Column(db.Integer, autoincrement=True)
-        name = db.Column(db.Unicode(50))
-        locale = db.Column(LocaleType)
+        id = sa.Column(sa.Integer, autoincrement=True)
+        name = sa.Column(sa.Unicode(50))
+        locale = sa.Column(LocaleType)
 
 
     user = User()
@@ -143,9 +195,9 @@ Example ::
 
     class Event(Base):
         __tablename__ = 'user'
-        id = db.Column(db.Integer, autoincrement=True)
-        name = db.Column(db.Unicode(255))
-        estimated_number_of_persons = db.Column(NumberRangeType)
+        id = sa.Column(sa.Integer, autoincrement=True)
+        name = sa.Column(sa.Unicode(255))
+        estimated_number_of_persons = sa.Column(NumberRangeType)
 
 
     party = Event(name=u'party')
@@ -190,8 +242,8 @@ Example ::
 
     class User(Base):
         __tablename__ = 'user'
-        id = db.Column(db.Integer, autoincrement=True)
-        hobbies = db.Column(ScalarListType())
+        id = sa.Column(sa.Integer, autoincrement=True)
+        hobbies = sa.Column(ScalarListType())
 
 
     user = User()
@@ -209,8 +261,8 @@ You can easily set up integer lists too:
 
     class Player(Base):
         __tablename__ = 'player'
-        id = db.Column(db.Integer, autoincrement=True)
-        points = db.Column(ScalarListType(int))
+        id = sa.Column(sa.Integer, autoincrement=True)
+        points = sa.Column(ScalarListType(int))
 
 
     player = Player()

sqlalchemy_utils/types/choice.py

@@ -30,13 +30,15 @@ class Choice(object):
 class ChoiceType(types.TypeDecorator, ScalarCoercible):
     impl = types.Unicode(255)
 
-    def __init__(self, choices):
+    def __init__(self, choices, impl=None):
         if not choices:
             raise ImproperlyConfigured(
                 'ChoiceType needs list of choices defined.'
             )
         self.choices = choices
         self.choices_dict = dict(choices)
+        if impl:
+            self.impl = impl
 
     def _coerce(self, value):
         if value is None:

tests/types/test_choice_type.py

@@ -5,9 +5,6 @@ from tests import TestCase
 
 
 class TestChoice(object):
-    # def test_init(self):
-    #     assert Choice(1, 1) == Choice(Choice(1, 1))
-
     def test_equality_operator(self):
         assert Choice(1, 1) == 1
         assert 1 == Choice(1, 1)
@@ -54,3 +51,9 @@ class TestChoiceType(TestCase):
     def test_throws_exception_if_no_choices_given(self):
         with raises(ImproperlyConfigured):
             ChoiceType([])
+
+
+class TestChoiceTypeWithCustomUnderlyingType(TestCase):
+    def test_init_type(self):
+        type_ = ChoiceType([(1, u'something')], impl=sa.Integer)
+        assert type_.impl == sa.Integer