summaryrefslogtreecommitdiff
path: root/sleekxmpp/xmlstream/tostring.py
blob: 8e729f79eba95badfc14e4f8fc73b7ed08279fe3 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
# -*- coding: utf-8 -*-
"""
    sleekxmpp.xmlstream.tostring
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~

    This module converts XML objects into Unicode strings and
    intelligently includes namespaces only when necessary to
    keep the output readable.

    Part of SleekXMPP: The Sleek XMPP Library

    :copyright: (c) 2011 Nathanael C. Fritz
    :license: MIT, see LICENSE for more details
"""

import sys

if sys.version_info < (3, 0):
    import types


def tostring(xml=None, xmlns='', stanza_ns='', stream=None,
             outbuffer='', top_level=False):
    """Serialize an XML object to a Unicode string.

    If namespaces are provided using ``xmlns`` or ``stanza_ns``, then
    elements that use those namespaces will not include the xmlns attribute
    in the output.

    :param XML xml: The XML object to serialize.
    :param string xmlns: Optional namespace of an element wrapping the XML
                         object.
    :param string stanza_ns: The namespace of the stanza object that contains
                             the XML object.
    :param stream: The XML stream that generated the XML object.
    :param string outbuffer: Optional buffer for storing serializations
                             during recursive calls.
    :param bool top_level: Indicates that the element is the outermost
                           element.


    :type xml: :py:class:`~xml.etree.ElementTree.Element`
    :type stream: :class:`~sleekxmpp.xmlstream.xmlstream.XMLStream`

    :rtype: Unicode string
    """
    # Add previous results to the start of the output.
    output = [outbuffer]

    # Extract the element's tag name.
    tag_name = xml.tag.split('}', 1)[-1]

    # Extract the element's namespace if it is defined.
    if '}' in xml.tag:
        tag_xmlns = xml.tag.split('}', 1)[0][1:]
    else:
        tag_xmlns = ''

    default_ns = ''
    stream_ns = ''
    if stream:
        default_ns = stream.default_ns
        stream_ns = stream.stream_ns

    # Output the tag name and derived namespace of the element.
    namespace = ''
    if top_level and tag_xmlns not in ['', default_ns, stream_ns] or \
            tag_xmlns not in ['', xmlns, stanza_ns, stream_ns]:
        namespace = ' xmlns="%s"' % tag_xmlns
    if stream and tag_xmlns in stream.namespace_map:
        mapped_namespace = stream.namespace_map[tag_xmlns]
        if mapped_namespace:
            tag_name = "%s:%s" % (mapped_namespace, tag_name)
    output.append("<%s" % tag_name)
    output.append(namespace)

    # Output escaped attribute values.
    for attrib, value in xml.attrib.items():
        value = xml_escape(value)
        if '}' not in attrib:
            output.append(' %s="%s"' % (attrib, value))
        else:
            attrib_ns = attrib.split('}')[0][1:]
            attrib = attrib.split('}')[1]
            if stream and attrib_ns in stream.namespace_map:
                mapped_ns = stream.namespace_map[attrib_ns]
                if mapped_ns:
                    output.append(' %s:%s="%s"' % (mapped_ns,
                                                   attrib,
                                                   value))

    if len(xml) or xml.text:
        # If there are additional child elements to serialize.
        output.append(">")
        if xml.text:
            output.append(xml_escape(xml.text))
        if len(xml):
            for child in xml.getchildren():
                output.append(tostring(child, tag_xmlns, stanza_ns, stream))
        output.append("</%s>" % tag_name)
    elif xml.text:
        # If we only have text content.
        output.append(">%s</%s>" % (xml_escape(xml.text), tag_name))
    else:
        # Empty element.
        output.append(" />")
    if xml.tail:
        # If there is additional text after the element.
        output.append(xml_escape(xml.tail))
    return ''.join(output)


def xml_escape(text):
    """Convert special characters in XML to escape sequences.

    :param string text: The XML text to convert.
    :rtype: Unicode string
    """
    if sys.version_info < (3, 0):
        if type(text) != types.UnicodeType:
            text = unicode(text, 'utf-8', 'ignore')

    text = list(text)
    escapes = {'&': '&amp;',
               '<': '&lt;',
               '>': '&gt;',
               "'": '&apos;',
               '"': '&quot;'}
    for i, c in enumerate(text):
        text[i] = escapes.get(c, c)
    return ''.join(text)