Author: mark
Date: 2008-08-12 06:43:48 -0600 (Tue, 12 Aug 2008)
New Revision: 3544
Modified:
FormEncode/trunk/formencode/compound.py
Log:
first implementation of Pipe() as deviation from All()
Modified: FormEncode/trunk/formencode/compound.py
===================================================================
--- FormEncode/trunk/formencode/compound.py 2008-08-12 12:39:35 UTC (rev 3543)
+++ FormEncode/trunk/formencode/compound.py 2008-08-12 12:43:48 UTC (rev 3544)
@@ -5,7 +5,7 @@
from api import *
# @@ ianb 2005-05: should CompoundValidator be included?
-__all__ = ['Any', 'All']
+__all__ = ['Any', 'All', 'Pipe']
############################################################
## Compound Validators
@@ -169,3 +169,46 @@
def is_empty(self, value):
# sub-validators should handle emptiness.
return False
+
+class Pipe(All):
+ """
+ This class works like 'All', all validators muss pass, but the result
+ of one validation pass is handled over to the next validator. A behaviour
+ known to Unix and GNU users as 'pipe'.
+
+ ::
+
+ >>> from validators import DictConverter
+ >>> pv = Pipe(validators=[DictConverter({1: 2}), DictConverter({2: 3}), DictConverter({3: 4})])
+ >>> pv.to_python(1)
+ 4
+ >>> pv.to_python(1)
+ 4
+ >>> pv.from_python(4)
+ 1
+ >>> pv.from_python(4)
+ 1
+ >>> pv.to_python(1)
+ 4
+
+ """
+
+ def __repr__(self):
+ return '<Pipe %s>' % self.validators
+
+ def attempt_convert(self, value, state, validate):
+ # To preserve the order of the transformations, we do them
+ # differently when we are converting to and from python.
+ if validate is from_python:
+ validators = list(self.validators)
+ validators.reverse()
+ else:
+ validators = self.validators
+ try:
+ for validator in validators:
+ value = validate(validator, value, state)
+ return value
+ except Invalid:
+ if self.if_invalid is NoDefault:
+ raise
+ return self.if_invalid
|
