Cheetah: Python-Powered Template Engine

Hello,

I have to apply filter to placeholders which can have None value. However,
the filter isn't apply.

For example :

import Cheetah.Template
from Cheetah.Filters import Filter

class MyFilter(Filter):

    def filter(self, val, **kw):

        return "tit"


if __name__ == '__main__':

    print "test01"

    searchList=[{'myvar1': u'test'}, {'myvar2': None}]

    t = Cheetah.Template.Template('''
        1. -${getVar('myvar1', '456')}-
        2. -${getVar('myvar2', ''), maxlen=2}-
        3. -${getVar('myvar3', None), maxlen=2}-
        ''', searchList,
        filter=MyFilter
        )
    print t

The output is as follow :

1. -tit-
2. --
3. --

Is there any way to apply filter to None value ?

Thanks a lot.

Thibaud