formencode additional extended validators

formencodeext.py

from formencode import FancyValidator, Invalid
import dateutil
import formencode

class validators:
    
    class ISODateTime(FancyValidator):
        """
        Validate and converts ISO formatted datetime string to python
        datetime object
        """ 
        
        messages = {
            'malformed': '%(date)s is not an ISO format.'
        }
        
        def _to_python(self, value, state):
            return dateutil.parser.parse(value)
        
        # Before conversion by _to_python
        def validate_other(self, value, state):
            try:
                dateutil.parser.parse(value)
            except:
                raise Invalid(self.message("malformed", state, date=value),
                              value, state)
            
    class Mixed(FancyValidator):
        """
        This validator takes dictionary of key and its validator and perform
        validation on each member
        
        Dictionary should be of key - validator only.
        
        .. Note:: Further nesting is not support at the moment
        """
        
        validator_dict = {}
        value_dict = {}
        
        def __init__(self, *args, **kw):
            self.validator_dict = args[0]            
            FancyValidator.__init__(self, **kw)
            
        def to_python(self, value, state):
            Schema = type('Schema', (formencode.Schema,), self.validator_dict)            
            return Schema.to_python(value)