"""
    Slixmpp: The Slick XMPP Library
    Copyright (C) 2011  Nathanael C. Fritz
    This file is part of Slixmpp.

    See the file LICENSE for copying permission.
"""

from slixmpp.xmlstream import ElementBase, ET


class Session(ElementBase):

    """
    """

    name = 'session'
    namespace = 'urn:ietf:params:xml:ns:xmpp-session'
    interfaces = {'optional'}
    plugin_attrib = 'session'

    def get_optional(self):
        return self.xml.find('{%s}optional' % self.namespace) is not None

    def set_optional(self, value):
        if value:
            optional = ET.Element('{%s}optional' % self.namespace)
            self.xml.append(optional)
        else:
            self.del_optional()

    def del_optional(self):
        optional = self.xml.find('{%s}optional' % self.namespace)
        self.xml.remove(optional)