Merge pull request #24 from sergei-maertens/feature/deconstructible_v…

…alidator

Made the validator deconstructible in Django 1.7+, fixing #15

Changelog.rst

@@ -2,6 +2,20 @@
 Changelog
 =========
 
+1.4 to 1.4.1
+------------
+This is a small release that fixes some ugliness. In Django 1.7 and up, the
+validator can now be used as documented in the readme. Before this version, the
+error::
+
+    ValueError: Cannot serialize: <bound method DjangoChoicesMeta.validator of <class 'choices.models.MyModel.Choices'>>
+
+would be raised, and a workaround was to define a validator function calling the
+choices' validator, requiring everything to be defined in the module scope.
+
+This is now fixed by moving to a class based validator which is deconstructible.
+
+
 1.3 to 1.4
 ----------
 * Added support for upcoming Django 1.9, by preferring stlib SortedDict over

LICENSE

@@ -1,4 +1,4 @@
-Copyright (c) 2011-2013 Jason Webb
+Copyright (c) 2011-2015 Jason Webb
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal

README.rst

@@ -59,6 +59,7 @@ With this::
             Customer = ChoiceItem("C")
             Employee = ChoiceItem("E")
             Groundhog = ChoiceItem("G")
+
         # Fields
         name = models.CharField(max_length=32)
         type = models.CharField(max_length=1,

djchoices/__init__.py

@@ -1,4 +1,5 @@
 from djchoices.choices import ChoiceItem, DjangoChoices, C
 
 __version__ = '1.4'
+
 __all__ = ["ChoiceItem", "DjangoChoices", "C"]

djchoices/choices.py

@@ -1,19 +1,14 @@
 import re
+
 from django.core.exceptions import ValidationError
 
-try:
-    from collections import OrderedDict
-except ImportError:  # Py2.6, fall back to Django's implementation
-    from django.utils.datastructures import SortedDict as OrderedDict
+from .compat import deconstructible, OrderedDict, six
 
-try:
-    from django.utils import six
-except ImportError:
-    import six
 
 __all__ = ["ChoiceItem", "DjangoChoices", "C"]
 
-### Support Functionality (Not part of public API ###
+
+# Support Functionality (Not part of public API)
 
 class Labels(dict):
     def __getattribute__(self, name):
@@ -22,42 +17,53 @@ def __getattribute__(self, name):
             return result
         else:
             raise AttributeError("Label for field %s was not found." % name)
+
     def __setattr__(self, name, value):
         self[name] = value
 
-### End Support Functionality ###
+
+class StaticProp(object):
+
+    def __init__(self, value):
+        self.value = value
+
+    def __get__(self, obj, objtype):
+        return self.value
+
+# End Support Functionality
+
 
 class ChoiceItem(object):
     """
-    Describes a choice item.  The label is usually the field name so label can
-    normally be left blank.  Set a label if you need characters that are illegal
-    in a python identifier name (ie: "DVD/Movie").
+    Describes a choice item.
+
+    The label is usually the field name so label can normally be left blank.
+    Set a label if you need characters that are illegal in a python identifier
+    name (ie: "DVD/Movie").
     """
     order = 0
+
     def __init__(self, value=None, label=None, order=None):
         self.value = value
+        self.label = label
+
         if order:
             self.order = order
         else:
             ChoiceItem.order += 1
             self.order = ChoiceItem.order
-        self.label = label
 
 # Shorter convenience alias.
 C = ChoiceItem
 
+
 class DjangoChoicesMeta(type):
     """
     Metaclass that writes the choices class.
     """
     name_clean = re.compile(r"_+")
-    def __new__(cls, name, bases, attrs):
-        class StaticProp(object):
-            def __init__(self, value):
-                self.value = value
-            def __get__(self, obj, objtype):
-                return self.value
 
+    def __new__(cls, name, bases, attrs):
         fields = {}
         labels = Labels()
         values = {}
@@ -80,9 +86,10 @@ def __get__(self, obj, objtype):
         for field_name in fields:
             val = fields[field_name]
             if isinstance(val, ChoiceItem):
-                if not val.label is None:
+                if val.label is not None:
                     label = val.label
                 else:
+                    # TODO: mark translatable by default?
                     label = cls.name_clean.sub(" ", field_name)
 
                 val0 = label if val.value is None else val.value
@@ -97,18 +104,32 @@ def __get__(self, obj, objtype):
         attrs["labels"] = labels
         attrs["values"] = values
         attrs["_fields"] = fields
+        attrs["validator"] = ChoicesValidator(values)
 
         return super(DjangoChoicesMeta, cls).__new__(cls, name, bases, attrs)
 
+
+@deconstructible
+class ChoicesValidator(object):
+
+    def __init__(self, values):
+        self.values = values
+
+    def __call__(self, value):
+        if value not in self.values:
+            raise ValidationError('Select a valid choice. %(value)s is not '
+                                  'one of the available choices.')
+
+    def __eq__(self, other):
+        return isinstance(other, ChoicesValidator) and self.values == other.values
+
+    def __ne__(self, other):
+        return not (self == other)
+
+
 class DjangoChoices(six.with_metaclass(DjangoChoicesMeta)):
     order = 0
     choices = ()
     labels = Labels()
     values = {}
-
-    @classmethod
-    def validator(cls, value):
-        if value not in cls.values:
-            raise ValidationError('Select a valid choice. %(value)s is not '
-                                  'one of the available choices.')
-
+    validator = None

djchoices/compat.py

@@ -0,0 +1,21 @@
+"""
+Module to handle different Django/Python version libraries.
+"""
+try:
+    from collections import OrderedDict
+except ImportError:  # Py2.6, fall back to Django's implementation
+    from django.utils.datastructures import SortedDict as OrderedDict  # pragma: no cover
+
+
+try:
+    from django.utils import six
+except ImportError:
+    import six  # pragma: no cover
+
+
+try:
+    from django.utils.deconstruct import deconstructible
+except ImportError:
+    # just return a noop decorator
+    def deconstructible(cls):
+        return cls

djchoices/tests/test_choices.py

@@ -1,30 +1,37 @@
 try:
-  import unittest2 as unittest
+    import unittest2 as unittest
 except ImportError:
-  import unittest
+    import unittest
 
 from djchoices import DjangoChoices, C, ChoiceItem
 
+from .utils import has_new_migrations
+
+
 class NumericTestClass(DjangoChoices):
     Item_0 = C(0)
     Item_1 = C(1)
     Item_2 = C(2)
     Item_3 = C(3)
 
+
 class StringTestClass(DjangoChoices):
     empty = ChoiceItem("", "")
     One = ChoiceItem("O")
     Two = ChoiceItem("T")
     Three = ChoiceItem("H")
 
+
 class SubClass1(NumericTestClass):
     Item_4 = C(4)
     Item_5 = C(5)
 
+
 class SubClass2(SubClass1):
     Item_6 = C(6)
     Item_7 = C(7)
 
+
 class EmptyValueClass(DjangoChoices):
     Option1 = ChoiceItem()
     Option2 = ChoiceItem()
@@ -148,3 +155,10 @@ def test_empty_value_class(self):
         self.assertEqual(choices[0][0], "Option1")
         self.assertEqual(choices[1][0], "Option2")
         self.assertEqual(choices[2][0], "Option3")
+
+    @unittest.skipUnless(*has_new_migrations())
+    def test_deconstructible_validator(self):
+        deconstructed = NumericTestClass.validator.deconstruct()
+        self.assertEqual(deconstructed, (
+            'djchoices.choices.ChoicesValidator', (NumericTestClass.values,), {}
+        ))

djchoices/tests/utils.py

@@ -0,0 +1,5 @@
+import django
+
+
+def has_new_migrations():
+    return (django.VERSION[:2] >= (1, 7), "Test requires the Django migrations introduced in Django 1.7")

runtests.py

@@ -1,11 +1,12 @@
 try:
-  import unittest2 as unittest
+    import unittest2 as unittest
 except ImportError:
-  import unittest
+    import unittest
 
 from os import path
 from sys import stdout
 
+
 if __name__ == "__main__":
     disc_folder = path.abspath(path.dirname(__file__))