Clean up and unify tostring once and for all.

Packaging for Python3 just got easier.

1 files changed, 123 insertions, 0 deletions

diff --git a/sleekxmpp/xmlstream/tostring.py b/sleekxmpp/xmlstream/tostring.py
new file mode 100644
index 00000000..f9674b15
--- /dev/null
+++ b/sleekxmpp/xmlstream/tostring.py
@@ -0,0 +1,123 @@
+"""
+    SleekXMPP: The Sleek XMPP Library
+    Copyright (C) 2010  Nathanael C. Fritz
+    This file is part of SleekXMPP.
+
+    See the file LICENSE for copying permission.
+"""
+
+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.
+
+    Arguments:
+        xml       -- The XML object to serialize. If the value is None,
+                     then the XML object contained in this stanza
+                     object will be used.
+        xmlns     -- Optional namespace of an element wrapping the XML
+                     object.
+        stanza_ns -- The namespace of the stanza object that contains
+                     the XML object.
+        stream    -- The XML stream that generated the XML object.
+        outbuffer -- Optional buffer for storing serializations during
+                     recursive calls.
+        top_level -- Indicates that the element is the outermost
+                     element.
+    """
+    # 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.
+
+    Arguments:
+        text -- The XML text to convert.
+    """
+    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)