Source code for slixmpp.xmlstream.tostring

# slixmpp.xmlstream.tostring
# ~~~~~~~~~~~~~~~~~~~~~~~~~~
# This module converts XML objects into Unicode strings and
# intelligently includes namespaces only when necessary to
# keep the output readable.
# Part of Slixmpp: The Slick XMPP Library
# :copyright: (c) 2011 Nathanael C. Fritz
# :license: MIT, see LICENSE for more details
from __future__ import annotations

from typing import Optional, Set, TYPE_CHECKING
from xml.etree.ElementTree import Element
if TYPE_CHECKING:
    from slixmpp.xmlstream import XMLStream

XML_NS = 'http://www.w3.org/XML/1998/namespace'


[docs] def tostring(xml: Optional[Element] = None, xmlns: str = '', stream: Optional[XMLStream] = None, outbuffer: str = '', top_level: bool = False, open_only: bool = False, namespaces: Optional[Set[str]] = None) -> str: """Serialize an XML object to a Unicode string. If an outer xmlns is provided using ``xmlns``, then the current element's namespace will not be included if it matches the outer namespace. An exception is made for elements that have an attached stream, and appear at the stream root. :param XML xml: The XML object to serialize. :param string xmlns: Optional namespace of an element wrapping 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. :param set namespaces: Track which namespaces are in active use so that new ones can be declared when needed. :type xml: :py:class:`~xml.etree.ElementTree.Element` :type stream: :class:`~slixmpp.xmlstream.xmlstream.XMLStream` :rtype: Unicode string """ if xml is None: return '' # Add previous results to the start of the output. output = [outbuffer] # Extract the element's tag name. tag_split = xml.tag.split('}', 1) tag_name = tag_split[-1] # Extract the element's namespace if it is defined. if '}' in xml.tag: tag_xmlns = tag_split[0][1:] else: tag_xmlns = '' default_ns = '' stream_ns = '' use_cdata = False if stream: default_ns = stream.default_ns stream_ns = stream.stream_ns use_cdata = stream.use_cdata # Output the tag name and derived namespace of the element. namespace = '' if tag_xmlns: if top_level and tag_xmlns not in [default_ns, xmlns, stream_ns] \ or not top_level and tag_xmlns != xmlns: 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. new_namespaces = set() for attrib, value in xml.attrib.items(): value = escape(value, use_cdata) if '}' not in attrib: output.append(' %s="%s"' % (attrib, value)) else: attrib_split = attrib.split('}') attrib_ns = attrib_split[0][1:] attrib = attrib_split[1] if attrib_ns == XML_NS: output.append(' xml:%s="%s"' % (attrib, value)) elif stream and attrib_ns in stream.namespace_map: mapped_ns = stream.namespace_map[attrib_ns] if mapped_ns: if namespaces is None: namespaces = set() if attrib_ns not in namespaces: namespaces.add(attrib_ns) new_namespaces.add(attrib_ns) output.append(' xmlns:%s="%s"' % ( mapped_ns, attrib_ns)) output.append(' %s:%s="%s"' % ( mapped_ns, attrib, value)) if open_only: # Only output the opening tag, regardless of content. output.append(">") return ''.join(output) if len(xml) or xml.text: # If there are additional child elements to serialize. output.append(">") if xml.text: output.append(escape(xml.text, use_cdata)) if len(xml): for child in xml: output.append(tostring(child, tag_xmlns, stream, namespaces=namespaces)) output.append("</%s>" % tag_name) elif xml.text: # If we only have text content. output.append(">%s</%s>" % (escape(xml.text, use_cdata), tag_name)) else: # Empty element. output.append(" />") if xml.tail: # If there is additional text after the element. output.append(escape(xml.tail, use_cdata)) for ns in new_namespaces: # Remove namespaces introduced in this context. This is necessary # because the namespaces object continues to be shared with other # contexts. if namespaces is not None: namespaces.remove(ns) return ''.join(output)
def escape(text: str, use_cdata: bool = False) -> str: """Convert special characters in XML to escape sequences. :param string text: The XML text to convert. :rtype: Unicode string """ escapes = {'&': '&amp;', '<': '&lt;', '>': '&gt;', "'": '&apos;', '"': '&quot;'} if not use_cdata: return ''.join(escapes.get(c, c) for c in text) else: escape_needed = False for c in text: if c in escapes: escape_needed = True break if escape_needed: escaped = map(lambda x : "<![CDATA[%s]]>" % x, text.split("]]>")) return "<![CDATA[]]]><![CDATA[]>]]>".join(escaped) return text def _get_highlight(): try: from pygments import highlight from pygments.lexers import get_lexer_by_name from pygments.formatters import Terminal256Formatter LEXER = get_lexer_by_name('xml') FORMATTER = Terminal256Formatter() class Highlighter: __slots__ = ['string'] def __init__(self, string): self.string = string def __str__(self): return highlight(str(self.string), LEXER, FORMATTER).strip() return Highlighter except ImportError: return lambda x: x highlight = _get_highlight()