Fixed #2364: added NumberIsInRange validator. Thanks, Matt McClanahan.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@4039 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/core/validators.py

@@ -353,6 +353,38 @@ class UniqueAmongstFieldsWithPrefix(object):
             if field_name != self.field_name and value == field_data:
                 raise ValidationError, self.error_message
 
+class NumberIsInRange(object):
+    """
+    Validator that tests if a value is in a range (inclusive).
+    """
+    def __init__(self, lower=None, upper=None, error_message=''):
+        self.lower, self.upper = lower, upper
+        if not error_message:
+            if lower and upper:
+                self.error_message = gettext("This value must be between %s and %s.") % (lower, upper)
+            elif lower:
+                self.error_message = gettext("This value must be at least %s.") % lower
+            elif upper:
+                self.error_message = gettext("This value must be no more than %s.") % upper
+        else:
+            self.error_message = error_message
+
+    def __call__(self, field_data, all_data):
+        # Try to make the value numeric. If this fails, we assume another 
+        # validator will catch the problem.
+        try:
+            val = float(field_data)
+        except ValueError:
+            return
+            
+        # Now validate
+        if self.lower and self.upper and (val < self.lower or val > self.upper):
+            raise ValidationError(self.error_message)
+        elif self.lower and val < self.lower:
+            raise ValidationError(self.error_message)
+        elif self.upper and val > self.upper:
+            raise ValidationError(self.error_message)
+
 class IsAPowerOf(object):
     """
     >>> v = IsAPowerOf(2)

docs/forms.txt

@@ -610,6 +610,15 @@ fails. If no message is passed in, a default message is used.
     string "123" is less than the string "2", for example. If you don't want
     string comparison here, you will need to write your own validator.
 
+``NumberIsInRange``
+    Takes two boundary number, ``lower`` and ``upper`` and checks that the
+    field is greater than ``lower`` (if given) and less than ``upper`` (if
+    given).  
+    
+    Both checks are inclusive; that is, ``NumberIsInRange(10, 20)`` will allow
+    values of both 10 and 20.  This validator only checks numeric fields
+    (i.e. floats and integer fields).
+
 ``IsAPowerOf``
     Takes an integer argument and when called as a validator, checks that the
     field being validated is a power of the integer.