Source code for todopy.filter

# vim: set fileencoding=utf-8 :
# Todo.txt manager in Python
# Copyright (C) 2011 Ilkka Laukkanen <ilkka.s.laukkanen@gmail.com>
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

class StringFilter(object):
    """Filter todo model based on a string.

    Only those todos that the string matches are passed thru the filter.

    >>> from model import Model
    >>> m = Model()
    >>> m.extend(["My first todo", "My second todo", u'Meikän unicode-todo'])
    >>> f = StringFilter("second", m)
    >>> len(f)
    1
    >>> f.total()
    3
    >>> list([t.todo for t in f])
    ['My second todo']
    >>> f = StringFilter("todo", m)
    >>> len(f)
    3
    >>> list([t.todo for t in f])
    ['My first todo', 'My second todo', u'Meik\\xc3\\xa4n unicode-todo']
    >>> f = StringFilter('first', StringFilter('todo', m))
    >>> len(f)
    1
    >>> f.total()
    3
    >>> list([t.todo for t in f])
    ['My first todo']
    """
    def __init__(self, string, model):
        self.string = string
        self.model = model

    @staticmethod
    def find_as_utf8(needle, haystack):
        needle = unicode(needle) if type(needle) != unicode else needle
        haystack = unicode(haystack) if type(haystack) != unicode else haystack
        return needle in haystack

    def __iter__(self):
        class Iter(object):
            def __init__(self, filter):
                self.filter = filter
                self.iter = iter(self.filter.model)
            def __iter__(self):
                return self
            def next(self):
                candidate = self.iter.next()
                while not StringFilter.find_as_utf8(self.filter.string, candidate.todo):
                    candidate = self.iter.next()
                return candidate
        return Iter(self)

    def __len__(self):
        return len(list([x for x in self.model if StringFilter.find_as_utf8(self.string, x.todo)]))

    def total(self):
        return self.model.total()