From cb6607895d43a12d9ae1e98f8de3243b9414f0d2 Mon Sep 17 00:00:00 2001
From: Timothy Warren <timothy.warren@level12.io>
Date: Tue, 5 Dec 2017 18:25:57 -0500
Subject: [PATCH 1/5] fis-climate#1348 Refactor `Column`s to use class
 attributes (rather than initialization parameters) as the primary
 configuration method

---
 webgrid/__init__.py         | 167 +++++++++++++++----------------
 webgrid/tests/test_utils.py | 189 ++++++++++++++++++++++++++++++++++++
 webgrid/utils.py            |  92 ++++++++++++++++++
 3 files changed, 358 insertions(+), 90 deletions(-)
 create mode 100644 webgrid/tests/test_utils.py

diff --git a/webgrid/__init__.py b/webgrid/__init__.py
index b081142..f1e1f81 100644
--- a/webgrid/__init__.py
+++ b/webgrid/__init__.py
@@ -17,6 +17,10 @@
 from werkzeug.datastructures import MultiDict
 
 from .renderers import HTML, XLS
+from .utils import (
+    enumerate_class_attributes,
+    OverridableAttributeProperty
+)
 
 # conditional imports to support libs without requiring them
 try:
@@ -36,7 +40,7 @@
 
 class _None(object):
     """
-        A sentinal object to indicate no value
+        A sentinel object to indicate no value
     """
     pass
 
@@ -93,10 +97,16 @@ class Column(object):
         Column represents the fixed settings for a datagrid column
     """
     _creation_counter = 0
+
+    # NOTE: `key` and `render_in` have some property magic going on below
+    key = None
+    filter = None
+    can_sort = True
     xls_width = None
-    xls_num_format = None
     xls_style = None
-    render_in = 'html', 'xls'
+    xls_num_format = None
+    render_in = ('html', 'xls')
+    has_subtotal = False
 
     def __new__(cls, *args, **kwargs):
         col_inst = super(Column, cls).__new__(cls)
@@ -109,55 +119,68 @@ def _assign_to_grid(self):
         grid_cls_cols = grid_locals.setdefault('__cls_cols__', [])
         grid_cls_cols.append(self)
 
-    def __init__(self, label, key=None, filter=None, can_sort=True,
-                 xls_width=None, xls_style=None, xls_num_format=None,
-                 render_in=_None, has_subtotal=False, **kwargs):
+    def __init__(self, label, key=_None, filter=_None, **kwargs):
+
         self.label = label
-        self.key = key
-        self.filter = filter
-        self.filter_for = None
-        self.filter_op = None
-        self._create_order = False
-        self.can_sort = can_sort
-        self.has_subtotal = has_subtotal
+        self.expr = None
+
+        for attr in enumerate_class_attributes(self):
+            if attr in kwargs:
+                setattr(self, attr, kwargs.pop(attr))
+
+        if key is not _None:
+            self.key = key
+
+        if filter is not _None:
+            self.filter = filter
+
         self.kwargs = kwargs
         self.grid = None
+
+        # filters can be sent in as a class (not class instance) if needed
+        if inspect.isclass(self.filter):
+            if self.expr is None:
+                raise ValueError('the filter was a class type, but no'
+                                 ' column-like object is available from "key" to pass in as'
+                                 ' as the first argument')
+            self.filter = self.filter(self.expr)
+
+    key = OverridableAttributeProperty('key', key)
+    @key.setter
+    def key(self, name, value):
         self.expr = None
-        if render_in is not _None:
-            self.render_in = ensure_tuple(render_in)
-        if xls_width:
-            self.xls_width = xls_width
-        if xls_num_format:
-            self.xls_num_format = xls_num_format
-        if xls_style:
-            self.xls_style = xls_style
 
         # if the key isn't a base string, assume its a column-like object that
         # works with a SA Query instance
-        if key is None:
+        if value is None:
             self.can_sort = False
-        elif not isinstance(key, six.string_types):
-            self.expr = col = key
+
+        elif isinstance(value, six.string_types):
+            pass
+
+        else:
+            self.expr = value
+
             # use column.key, column.name, or None in that order
-            key = getattr(col, 'key', getattr(col, 'name', None))
+            key = getattr(value, 'key', getattr(value, 'name', None))
 
             if key is None:
                 raise ValueError('expected filter to be a SQLAlchemy column-like'
                                  ' object, but it did not have a "key" or "name"'
                                  ' attribute')
-            self.key = key
 
-        # filters can be sent in as a class (not class instance) if needed
-        if inspect.isclass(filter):
-            if self.expr is None:
-                raise ValueError('the filter was a class type, but no'
-                                 ' column-like object is available from "key" to pass in as'
-                                 ' as the first argument')
-            self.filter = filter(self.expr)
+            value = key
+
+        setattr(self, name, value)
+
+    render_in = OverridableAttributeProperty('render_in', render_in)
+    @render_in.setter
+    def render_in(self, name, value):
+        setattr(self, name, ensure_tuple(value))
 
     def new_instance(self, grid):
         cls = self.__class__
-        column = cls(self.label, self.key, None, self.can_sort, _dont_assign=True)
+        column = cls(self.label, self.key, None, can_sort=self.can_sort, _dont_assign=True)
         column.grid = grid
         column.expr = self.expr
 
@@ -173,13 +196,10 @@ def new_instance(self, grid):
         else:
             column.xlwt_stymat = None
 
-        # try to be smart about which attributes should get copied to the
-        # new instance by looking for attributes on the class that have the
-        # same name as arguments to the classes __init__ method
-        for argname in inspect.getargspec(self.__init__).args:
-            if argname != 'self' and hasattr(self, argname) and \
-                    argname not in ('label', 'key', 'filter', 'can_sort'):
-                setattr(column, argname, getattr(self, argname))
+        # copy the class attributes to the newly-instantiated column
+        for attr in enumerate_class_attributes(self):
+            if attr not in ('can_sort', 'filter', 'key', 'label'):
+                setattr(column, attr, getattr(self, attr))
 
         return column
 
@@ -274,13 +294,7 @@ def xlwt_stymat_calc(self, value):
 
 class LinkColumnBase(Column):
     link_attrs = {}
-
-    def __init__(self, label, key=None, filter=None, can_sort=True,
-                 link_label=None, xls_width=None, xls_style=None, xls_num_format=None,
-                 render_in=_None, **kwargs):
-        Column.__init__(self, label, key, filter, can_sort, xls_width,
-                        xls_style, xls_num_format, render_in, **kwargs)
-        self.link_label = link_label
+    link_label = None
 
     def render_html(self, record, hah):
         url = self.create_url(record)
@@ -295,16 +309,9 @@ def create_url(self, record):
 
 
 class BoolColumn(Column):
-
-    def __init__(self, label, key_or_filter=None, key=None, can_sort=True,
-                 reverse=False, true_label='True', false_label='False',
-                 xls_width=None, xls_style=None, xls_num_format=None,
-                 render_in=_None, **kwargs):
-        Column.__init__(self, label, key_or_filter, key, can_sort, xls_width,
-                        xls_style, xls_num_format, render_in, **kwargs)
-        self.reverse = reverse
-        self.true_label = true_label
-        self.false_label = false_label
+    false_label = 'False'
+    reverse = False
+    true_label = 'True'
 
     def format_data(self, data):
         if self.reverse:
@@ -315,23 +322,12 @@ def format_data(self, data):
 
 
 class YesNoColumn(BoolColumn):
-
-    def __init__(self, label, key_or_filter=None, key=None, can_sort=True,
-                 reverse=False, xls_width=None, xls_style=None, xls_num_format=None,
-                 render_in=_None, **kwargs):
-        BoolColumn.__init__(self, label, key_or_filter, key, can_sort, reverse,
-                            'Yes', 'No', xls_width, xls_style, xls_num_format, render_in, **kwargs)
+    false_label = 'No'
+    true_label = 'Yes'
 
 
 class DateColumnBase(Column):
-
-    def __init__(self, label, key_or_filter=None, key=None, can_sort=True,
-                 html_format=None, xls_width=None, xls_style=None, xls_num_format=None,
-                 render_in=_None, **kwargs):
-        Column.__init__(self, label, key_or_filter, key, can_sort, xls_width,
-                        xls_style, xls_num_format, render_in, **kwargs)
-        if html_format:
-            self.html_format = html_format
+    html_format = None
 
     def render_html(self, record, hah):
         data = self.extract_and_format_data(record)
@@ -387,28 +383,19 @@ class TimeColumn(DateColumnBase):
 
 
 class NumericColumn(Column):
+    curr = ''
+    dp = '.'
+    format_as = 'general'
+    neg = '-'
+    places = 2
+    pos = ''
+    sep = ','
+    trailneg = ''
     xls_fmt_general = '#,##0{dec_places};{neg_prefix}-#,##0{dec_places}'
     xls_fmt_accounting = '_($* #,##0{dec_places}_);{neg_prefix}_($* (#,##0{dec_places})' + \
                          ';_($* "-"??_);_(@_)'
     xls_fmt_percent = '0{dec_places}%;{neg_prefix}-0{dec_places}%'
-
-    def __init__(self, label, key_or_filter=None, key=None, can_sort=True,
-                 reverse=False, xls_width=None, xls_style=None, xls_num_format=None,
-                 render_in=_None, format_as='general', places=2, curr='',
-                 sep=',', dp='.', pos='', neg='-', trailneg='',
-                 xls_neg_red=True, has_subtotal=False, **kwargs):
-        Column.__init__(self, label, key_or_filter, key, can_sort, xls_width,
-                        xls_style, xls_num_format, render_in,
-                        has_subtotal, **kwargs)
-        self.places = places
-        self.curr = curr
-        self.sep = sep
-        self.dp = dp
-        self.pos = pos
-        self.neg = neg
-        self.trailneg = trailneg
-        self.xls_neg_red = xls_neg_red
-        self.format_as = format_as
+    xls_neg_red = True
 
     def html_decimal_format_opts(self, data):
         return (
diff --git a/webgrid/tests/test_utils.py b/webgrid/tests/test_utils.py
new file mode 100644
index 0000000..86378fd
--- /dev/null
+++ b/webgrid/tests/test_utils.py
@@ -0,0 +1,189 @@
+from nose.tools import eq_
+
+from webgrid.utils import (
+    enumerate_class_attributes,
+    OverridableAttributeProperty
+)
+
+class Test_enumerate_class_attributes:
+    def test_attribute_enumeration(self):
+        class A:
+            a = 123
+            b = 456
+
+        a = A()
+
+        eq_(enumerate_class_attributes(A), ['a', 'b'])
+        eq_(enumerate_class_attributes(a), ['a', 'b'])
+
+    def test_subclass_attributes(self):
+        class A:
+            a = 123
+
+        class B(A):
+            b = 456
+
+        eq_(enumerate_class_attributes(B), ['a', 'b'])
+
+    def test_methods_not_enumerated(self):
+        class A:
+            def foo(self):
+                pass
+
+        assert 'foo' not in enumerate_class_attributes(A)
+
+    def test_private_members_not_enumerated(self):
+        class A:
+            foo = 123
+            _bar = 456
+
+        eq_(enumerate_class_attributes(A), ['foo'])
+
+    def test_sorting(self):
+        class A:
+            b = 456
+            a = 123
+
+        eq_(enumerate_class_attributes(A), ['a', 'b'])
+
+    def test_properties(self):
+        class A:
+            a = 123
+            b = 456
+
+            @property
+            def c(self):
+                return 789
+
+        eq_(enumerate_class_attributes(A), ['a', 'b', 'c'])
+
+    def test_instance_variables_not_enumerated(self):
+        class A:
+            a = 123
+
+            def __init__(self):
+                self.b = 456
+
+        a = A()
+
+        eq_(enumerate_class_attributes(a), ['a'])
+
+
+class Test_OverridableAttributeProperty:
+    def test_class_value(self):
+        class Foo:
+            bar = 123
+
+            bar = OverridableAttributeProperty('bar', bar)
+
+        eq_(Foo.bar, 123)
+
+    def test_default_instance_value(self):
+        class Foo:
+            bar = 123
+
+            bar = OverridableAttributeProperty('bar', bar)
+
+        foo = Foo()
+        eq_(foo.bar, 123)
+
+    def test_class_value_writable_by_default(self):
+        class Foo:
+            bar = 123
+
+            bar = OverridableAttributeProperty('bar', bar)
+
+        Foo.bar = 345
+        eq_(Foo.bar, 345)
+
+    def test_instance_value_writable_by_default(self):
+        class Foo:
+            bar = 123
+
+            bar = OverridableAttributeProperty('bar', bar)
+
+        foo = Foo()
+        foo.bar = 999
+        eq_(foo.bar, 999)
+
+        eq_(Foo.bar, 123)
+
+    def test_setter(self):
+        class Foo:
+            bar = 123
+
+            bar = OverridableAttributeProperty('bar', bar)
+            @bar.setter
+            def bar(self, name, value):
+                setattr(self, name, 1000 - value)
+
+        foo = Foo()
+        eq_(foo.bar, 123)
+        foo.bar = 999
+        eq_(foo.bar, 1)
+
+    def test_instance_values_are_per_instance(self):
+        class Foo:
+            bar = 123
+
+            bar = OverridableAttributeProperty('bar', bar)
+            @bar.setter
+            def bar(self, name, value):
+                setattr(self, name, 1000 - value)
+
+        a = Foo()
+        b = Foo()
+
+        a.bar = 10
+        eq_(a.bar, 990)
+        eq_(b.bar, 123)
+
+    def test_behaves_in_init(self):
+        class Foo:
+            bar = 123
+
+            def __init__(self):
+                self.bar = 200
+
+            bar = OverridableAttributeProperty('bar', bar)
+            @bar.setter
+            def bar(self, name, value):
+                setattr(self, name, value * 2)
+
+        foo = Foo()
+        eq_(foo.bar, 400)
+
+    def test_property_inherits_properly(self):
+        class Foo:
+            bar = 123
+
+            bar = OverridableAttributeProperty('bar', bar)
+            @bar.setter
+            def bar(self, name, value):
+                setattr(self, name, value * 2)
+
+        class Bar(Foo):
+            pass
+
+        bar = Bar()
+        eq_(bar.bar, 123)
+        bar.bar = 200
+        eq_(bar.bar, 400)
+
+    def test_overriden_attribute_is_plain(self):
+        class Foo:
+            bar = 123
+
+            bar = OverridableAttributeProperty('bar', bar)
+            @bar.setter
+            def bar(self, name, value):
+                setattr(self, name, value * 2)
+
+        class Bar(Foo):
+            bar = 500
+
+        bar = Bar()
+        eq_(bar.bar, 500)
+        bar.bar = 200
+        eq_(bar.bar, 200)
+
diff --git a/webgrid/utils.py b/webgrid/utils.py
index a855b4d..facb272 100644
--- a/webgrid/utils.py
+++ b/webgrid/utils.py
@@ -1,3 +1,26 @@
+import inspect
+
+def enumerate_class_attributes(cls_or_instance):
+    """
+    Returns a sorted list of the class's attributes
+
+    This method will not return any attribute whose name
+    begins with an underscore.
+
+    :return:
+    """
+
+    if inspect.isclass(cls_or_instance):
+        cls = cls_or_instance
+    else:
+        cls = cls_or_instance.__class__
+
+    members = inspect.getmembers(cls, lambda attr: not inspect.isroutine(attr))
+    return sorted(
+        attribute
+        for (attribute, _) in members
+        if not attribute.startswith('_')
+    )
 
 
 def current_url(manager, root_only=False, host_only=False, strip_querystring=False,
@@ -49,3 +72,72 @@ def current_url(manager, root_only=False, host_only=False, strip_querystring=Fal
             retval = retval.replace('https://', 'http://', 1)
 
     return retval
+
+
+class OverridableAttributeProperty:
+    """
+    Create an overridable attribute property.
+
+    Say you have a class wherein you'd like to have some data
+    defined via class attributes. However, you also need to be
+    able to validate the data that is set on that attribute.
+    Further, you wish to have the name of the attribute "plain"
+    (that is, you don't want to have an internal value of `_foo`,
+    you just want that attribute `foo`).
+
+    This class provides custom setter capabilities while allowing
+    you to maintain the standard non-internal name.
+
+    This class performs a small bit of magic; of note, you should
+    be aware that setting a value on one of these properties will
+    create a instance value (currently named `_{name}_instance_value`)
+
+    Example:
+        class Foo:
+            foo = 123
+
+            . . .
+
+            # create the attribute property
+            # we need to pass the name (for the 'instance_value'),
+            # and the current value
+            foo = OverridableAttributeProperty('foo', foo)
+
+            # create the setter
+            # note that the setter takes an additional parameter `name`.
+            # This name should be used when setting the value
+            @foo.setter
+            def foo(self, name, value):
+                # validate `value`
+                value = . . .
+
+                # save to the internal name
+                setattr(self, name, value)
+
+    """
+    def __init__(self, name, class_value, fset=None):
+        self.name = name
+        self.class_value = class_value
+        self.fset = fset
+
+    @property
+    def instance_value_name(self):
+        return '_{}_instance_value'.format(self.name)
+
+    def __get__(self, obj, objtype):
+        if obj is None:
+            return self.class_value
+
+        return getattr(obj, self.instance_value_name, self.class_value)
+
+    def __set__(self, obj, value):
+        if self.fset is None:
+            setattr(obj, self.instance_value_name, value)
+
+        else:
+            self.fset(obj, self.instance_value_name, value)
+
+    def setter(self, fset):
+        return type(self)(self.name, self.class_value, fset)
+
+

From 93bf539dff76b131eb06e4581eab6d719d5d29e2 Mon Sep 17 00:00:00 2001
From: Timothy Warren <timothy.warren@level12.io>
Date: Tue, 5 Dec 2017 19:07:37 -0500
Subject: [PATCH 2/5] fis-climate#1348 Bump version number to indicate
 backwards-incompatibility

---
 webgrid/version.txt | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/webgrid/version.txt b/webgrid/version.txt
index a52e041..0ea3a94 100644
--- a/webgrid/version.txt
+++ b/webgrid/version.txt
@@ -1 +1 @@
-0.1.35
+0.2.0

From 53b3aebeb8fd449002bfb12a93fed5438d2ad7a8 Mon Sep 17 00:00:00 2001
From: Timothy Warren <timothy.warren@level12.io>
Date: Tue, 5 Dec 2017 19:13:14 -0500
Subject: [PATCH 3/5] fis-climate#1348 Add a quick description to the readme
 highlighting the change

---
 readme.rst | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

diff --git a/readme.rst b/readme.rst
index ecb3140..a872626 100644
--- a/readme.rst
+++ b/readme.rst
@@ -38,3 +38,30 @@ Current Status
 ---------------
 
 Currently beta quality.
+
+Changes in 0.2.0
+----------------
+
+This update includes backwards-incompatible changes that affect the way column classes
+are defined.
+
+From this point forward, column classes should declare their pertinent configuration options
+via class attributes, rather than as initialization parameters.
+
+Pre-0.2.0:
+
+    class SomeColumn(Column):
+        def __init__(self, label, key=None, filter=None, can_sort=False,
+                 link_label=None, xls_width=None, xls_style=None, xls_num_format=None,
+                 render_in=_None, **kwargs):
+            Column.__init__(self, label, key, filter, can_sort, xls_width,
+                        xls_style, xls_num_format, render_in, **kwargs)
+            self.link_label = link_label
+
+
+The equivalent code, beginning in 0.2.0:
+
+    class SomeColumn(Column):
+        can_sort = False
+        link_label = None
+

From 5fa424c32ebeab1d87ce907fa40047850d49fe93 Mon Sep 17 00:00:00 2001
From: Timothy Warren <timothy.warren@level12.io>
Date: Wed, 6 Dec 2017 01:14:04 -0500
Subject: [PATCH 4/5] fis-climate#1348 Fix linting errors

---
 webgrid/__init__.py         | 2 ++
 webgrid/tests/test_utils.py | 7 ++++++-
 webgrid/utils.py            | 3 +--
 3 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/webgrid/__init__.py b/webgrid/__init__.py
index f1e1f81..e959e31 100644
--- a/webgrid/__init__.py
+++ b/webgrid/__init__.py
@@ -146,6 +146,7 @@ def __init__(self, label, key=_None, filter=_None, **kwargs):
             self.filter = self.filter(self.expr)
 
     key = OverridableAttributeProperty('key', key)
+
     @key.setter
     def key(self, name, value):
         self.expr = None
@@ -174,6 +175,7 @@ def key(self, name, value):
         setattr(self, name, value)
 
     render_in = OverridableAttributeProperty('render_in', render_in)
+
     @render_in.setter
     def render_in(self, name, value):
         setattr(self, name, ensure_tuple(value))
diff --git a/webgrid/tests/test_utils.py b/webgrid/tests/test_utils.py
index 86378fd..4e61467 100644
--- a/webgrid/tests/test_utils.py
+++ b/webgrid/tests/test_utils.py
@@ -5,6 +5,7 @@
     OverridableAttributeProperty
 )
 
+
 class Test_enumerate_class_attributes:
     def test_attribute_enumeration(self):
         class A:
@@ -113,6 +114,7 @@ class Foo:
             bar = 123
 
             bar = OverridableAttributeProperty('bar', bar)
+
             @bar.setter
             def bar(self, name, value):
                 setattr(self, name, 1000 - value)
@@ -127,6 +129,7 @@ class Foo:
             bar = 123
 
             bar = OverridableAttributeProperty('bar', bar)
+
             @bar.setter
             def bar(self, name, value):
                 setattr(self, name, 1000 - value)
@@ -146,6 +149,7 @@ def __init__(self):
                 self.bar = 200
 
             bar = OverridableAttributeProperty('bar', bar)
+
             @bar.setter
             def bar(self, name, value):
                 setattr(self, name, value * 2)
@@ -158,6 +162,7 @@ class Foo:
             bar = 123
 
             bar = OverridableAttributeProperty('bar', bar)
+
             @bar.setter
             def bar(self, name, value):
                 setattr(self, name, value * 2)
@@ -175,6 +180,7 @@ class Foo:
             bar = 123
 
             bar = OverridableAttributeProperty('bar', bar)
+
             @bar.setter
             def bar(self, name, value):
                 setattr(self, name, value * 2)
@@ -186,4 +192,3 @@ class Bar(Foo):
         eq_(bar.bar, 500)
         bar.bar = 200
         eq_(bar.bar, 200)
-
diff --git a/webgrid/utils.py b/webgrid/utils.py
index facb272..c437ea6 100644
--- a/webgrid/utils.py
+++ b/webgrid/utils.py
@@ -1,5 +1,6 @@
 import inspect
 
+
 def enumerate_class_attributes(cls_or_instance):
     """
     Returns a sorted list of the class's attributes
@@ -139,5 +140,3 @@ def __set__(self, obj, value):
 
     def setter(self, fset):
         return type(self)(self.name, self.class_value, fset)
-
-

From 4e3b2e1746ad45e0e1921fdb3dce9b731e1efff4 Mon Sep 17 00:00:00 2001
From: Timothy Warren <timothy.warren@level12.io>
Date: Wed, 6 Dec 2017 02:25:00 -0500
Subject: [PATCH 5/5] fis-climate#1348 Fix Python2 support via new-style
 classes

---
 webgrid/tests/test_utils.py | 22 +++++++++++-----------
 webgrid/utils.py            |  2 +-
 2 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/webgrid/tests/test_utils.py b/webgrid/tests/test_utils.py
index 4e61467..68b02f6 100644
--- a/webgrid/tests/test_utils.py
+++ b/webgrid/tests/test_utils.py
@@ -6,7 +6,7 @@
 )
 
 
-class Test_enumerate_class_attributes:
+class Test_enumerate_class_attributes(object):
     def test_attribute_enumeration(self):
         class A:
             a = 123
@@ -70,9 +70,9 @@ def __init__(self):
         eq_(enumerate_class_attributes(a), ['a'])
 
 
-class Test_OverridableAttributeProperty:
+class Test_OverridableAttributeProperty(object):
     def test_class_value(self):
-        class Foo:
+        class Foo(object):
             bar = 123
 
             bar = OverridableAttributeProperty('bar', bar)
@@ -80,7 +80,7 @@ class Foo:
         eq_(Foo.bar, 123)
 
     def test_default_instance_value(self):
-        class Foo:
+        class Foo(object):
             bar = 123
 
             bar = OverridableAttributeProperty('bar', bar)
@@ -89,7 +89,7 @@ class Foo:
         eq_(foo.bar, 123)
 
     def test_class_value_writable_by_default(self):
-        class Foo:
+        class Foo(object):
             bar = 123
 
             bar = OverridableAttributeProperty('bar', bar)
@@ -98,7 +98,7 @@ class Foo:
         eq_(Foo.bar, 345)
 
     def test_instance_value_writable_by_default(self):
-        class Foo:
+        class Foo(object):
             bar = 123
 
             bar = OverridableAttributeProperty('bar', bar)
@@ -110,7 +110,7 @@ class Foo:
         eq_(Foo.bar, 123)
 
     def test_setter(self):
-        class Foo:
+        class Foo(object):
             bar = 123
 
             bar = OverridableAttributeProperty('bar', bar)
@@ -125,7 +125,7 @@ def bar(self, name, value):
         eq_(foo.bar, 1)
 
     def test_instance_values_are_per_instance(self):
-        class Foo:
+        class Foo(object):
             bar = 123
 
             bar = OverridableAttributeProperty('bar', bar)
@@ -142,7 +142,7 @@ def bar(self, name, value):
         eq_(b.bar, 123)
 
     def test_behaves_in_init(self):
-        class Foo:
+        class Foo(object):
             bar = 123
 
             def __init__(self):
@@ -158,7 +158,7 @@ def bar(self, name, value):
         eq_(foo.bar, 400)
 
     def test_property_inherits_properly(self):
-        class Foo:
+        class Foo(object):
             bar = 123
 
             bar = OverridableAttributeProperty('bar', bar)
@@ -176,7 +176,7 @@ class Bar(Foo):
         eq_(bar.bar, 400)
 
     def test_overriden_attribute_is_plain(self):
-        class Foo:
+        class Foo(object):
             bar = 123
 
             bar = OverridableAttributeProperty('bar', bar)
diff --git a/webgrid/utils.py b/webgrid/utils.py
index c437ea6..7acd92f 100644
--- a/webgrid/utils.py
+++ b/webgrid/utils.py
@@ -75,7 +75,7 @@ def current_url(manager, root_only=False, host_only=False, strip_querystring=Fal
     return retval
 
 
-class OverridableAttributeProperty:
+class OverridableAttributeProperty(object):
     """
     Create an overridable attribute property.