source: wokkel/delay.py @ 104:7de2ae0a6a88

Last change on this file since 104:7de2ae0a6a88 was 104:7de2ae0a6a88, checked in by Ralph Meijer <ralphm@…>, 9 years ago

Add support for the Delayed Delivery information formats.

File size: 3.2 KB
Line 
1# -*- test-case-name: wokkel.test.test_delay -*-
2#
3# Copyright (c) Ralph Meijer.
4# See LICENSE for details.
5
6"""
7Delayed Delivery.
8
9Support for comunicating Delayed Delivery information as specified by
10U{XEP-0203<http://xmpp.org/extensions/xep-0203.html>} and its predecessor
11U{XEP-0091<http://xmpp.org/extensions/xep-0091.html>}.
12"""
13
14from dateutil.parser import parse
15from dateutil.tz import tzutc
16
17from twisted.words.protocols.jabber.jid import InvalidFormat, JID
18from twisted.words.xish import domish
19
20NS_DELAY = 'urn:xmpp:delay'
21NS_JABBER_DELAY = 'jabber:x:delay'
22
23class Delay(object):
24    """
25    Delayed Delivery information.
26
27    Instances of this class represent delayed delivery information that can be
28    parsed from and rendered into both XEP-0203 and legacy XEP-0091 formats.
29
30    @ivar stamp: The timestamp the stanza was originally sent.
31    @type stamp: L{datetime.datetime}
32    @ivar sender: The optional entity that originally sent the stanza or
33        delayed its delivery.
34    @type sender: L{JID}
35    """
36
37    def __init__(self, stamp, sender=None):
38        self.stamp = stamp
39        self.sender = sender
40
41
42    def toElement(self, legacy=False):
43        """
44        Render this instance into a domish Element.
45
46        @param legacy: If C{True}, use the legacy XEP-0091 format.
47        @type legacy: C{bool}
48        """
49        if not self.stamp:
50            raise ValueError("stamp is required")
51        if self.stamp.tzinfo is None:
52            raise ValueError("stamp is not offset-aware")
53
54        if legacy:
55            element = domish.Element((NS_JABBER_DELAY, 'x'))
56            stampFormat = '%Y%m%dT%H:%M:%S'
57        else:
58            element = domish.Element((NS_DELAY, 'delay'))
59            stampFormat = '%Y-%m-%dT%H:%M:%SZ'
60
61        stamp = self.stamp.astimezone(tzutc())
62        element['stamp'] = stamp.strftime(stampFormat)
63
64        if self.sender:
65            element['from'] = self.sender.full()
66
67        return element
68
69
70    @staticmethod
71    def fromElement(element):
72        """
73        Create an instance from a domish Element.
74        """
75        try:
76            stamp = parse(element[u'stamp'])
77
78            # Assume UTC if no timezone was given
79            if stamp.tzinfo is None:
80                stamp = stamp.replace(tzinfo=tzutc())
81        except (KeyError, ValueError):
82            stamp = None
83
84        try:
85            sender = JID(element[u'from'])
86        except (KeyError, InvalidFormat):
87            sender = None
88
89        delay = Delay(stamp, sender)
90        return delay
91
92
93
94class DelayMixin(object):
95    """
96    Mixin for parsing delayed delivery information from stanzas.
97
98    This can be used as a mixin for subclasses of L{wokkel.generic.Stanza}
99    for parsing delayed delivery information. If both XEP-0203 and XEP-0091
100    formats are present, the former takes precedence.
101    """
102
103    delay = None
104
105    childParsers = {
106            (NS_DELAY, 'delay'): '_childParser_delay',
107            (NS_JABBER_DELAY, 'x'): '_childParser_legacyDelay',
108            }
109
110
111    def _childParser_delay(self, element):
112        self.delay = Delay.fromElement(element)
113
114
115    def _childParser_legacyDelay(self, element):
116        if not self.delay:
117            self.delay = Delay.fromElement(element)
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