Added HStoreField.

Thanks to `django-hstore` for inspiration in some areas, and many people
for reviews.

1 files changed, 50 insertions, 1 deletions

diff --git a/django/contrib/postgres/validators.py b/django/contrib/postgres/validators.py
index 353305949e..19d0a69765 100644
--- a/django/contrib/postgres/validators.py
+++ b/django/contrib/postgres/validators.py
@@ -1,5 +1,9 @@
+import copy
+
+from django.core.exceptions import ValidationError
 from django.core.validators import MaxLengthValidator, MinLengthValidator
-from django.utils.translation import ungettext_lazy
+from django.utils.deconstruct import deconstructible
+from django.utils.translation import ungettext_lazy, ugettext_lazy as _
 
 
 class ArrayMaxLengthValidator(MaxLengthValidator):
@@ -14,3 +18,48 @@ class ArrayMinLengthValidator(MinLengthValidator):
         'List contains %(show_value)d item, it should contain no fewer than %(limit_value)d.',
         'List contains %(show_value)d items, it should contain no fewer than %(limit_value)d.',
         'limit_value')
+
+
+@deconstructible
+class KeysValidator(object):
+    """A validator designed for HStore to require/restrict keys."""
+
+    messages = {
+        'missing_keys': _('Some keys were missing: %(keys)s'),
+        'extra_keys': _('Some unknown keys were provided: %(keys)s'),
+    }
+    strict = False
+
+    def __init__(self, keys, strict=False, messages=None):
+        self.keys = set(keys)
+        self.strict = strict
+        if messages is not None:
+            self.messages = copy.copy(self.messages)
+            self.messages.update(messages)
+
+    def __call__(self, value):
+        keys = set(value.keys())
+        missing_keys = self.keys - keys
+        if missing_keys:
+            raise ValidationError(self.messages['missing_keys'],
+                code='missing_keys',
+                params={'keys': ', '.join(missing_keys)},
+            )
+        if self.strict:
+            extra_keys = keys - self.keys
+            if extra_keys:
+                raise ValidationError(self.messages['extra_keys'],
+                    code='extra_keys',
+                    params={'keys': ', '.join(extra_keys)},
+                )
+
+    def __eq__(self, other):
+        return (
+            isinstance(other, self.__class__)
+            and (self.keys == other.keys)
+            and (self.messages == other.messages)
+            and (self.strict == other.strict)
+        )
+
+    def __ne__(self, other):
+        return not (self == other)