# pylint: disable=invalid-name,wrong-import-position,redefined-builtin
"""This class contains XML related utility functions."""
import sys
import re
import xml.etree.ElementTree as XML
# Create regular expression for filtering invalid characters, from:
# http://stackoverflow.com/questions/1707890/
# fast-way-to-filter-illegal-xml-unicode-chars-in-python
illegal_unichrs = [
(0x00, 0x08),
(0x0B, 0x0C),
(0x0E, 0x1F),
(0x7F, 0x84),
(0x86, 0x9F),
(0xD800, 0xDFFF),
(0xFDD0, 0xFDDF),
(0xFFFE, 0xFFFF),
(0x1FFFE, 0x1FFFF),
(0x2FFFE, 0x2FFFF),
(0x3FFFE, 0x3FFFF),
(0x4FFFE, 0x4FFFF),
(0x5FFFE, 0x5FFFF),
(0x6FFFE, 0x6FFFF),
(0x7FFFE, 0x7FFFF),
(0x8FFFE, 0x8FFFF),
(0x9FFFE, 0x9FFFF),
(0xAFFFE, 0xAFFFF),
(0xBFFFE, 0xBFFFF),
(0xCFFFE, 0xCFFFF),
(0xDFFFE, 0xDFFFF),
(0xEFFFE, 0xEFFFF),
(0xFFFFE, 0xFFFFF),
(0x10FFFE, 0x10FFFF),
]
illegal_ranges = [
"{}-{}".format(chr(low), chr(high))
for (low, high) in illegal_unichrs
if low < sys.maxunicode
]
illegal_xml_re = re.compile("[%s]" % "".join(illegal_ranges))
#: Commonly used namespaces, and abbreviations, used by `ns_tag`.
NAMESPACES = {
"dc": "http://purl.org/dc/elements/1.1/",
"upnp": "urn:schemas-upnp-org:metadata-1-0/upnp/",
"": "urn:schemas-upnp-org:metadata-1-0/DIDL-Lite/",
"ms": "http://www.sonos.com/Services/1.1",
"r": "urn:schemas-rinconnetworks-com:metadata-1-0/",
}
# Register common namespaces to assist in serialisation (avoids the ns:0
# prefixes in XML output )
for prefix, uri in NAMESPACES.items():
XML.register_namespace(prefix, uri)
[docs]def ns_tag(ns_id, tag):
"""Return a namespace/tag item.
Args:
ns_id (str): A namespace id, eg ``"dc"`` (see `NAMESPACES`)
tag (str): An XML tag, eg ``"author"``
Returns:
str: A fully qualified tag.
The ns_id is translated to a full name space via the :const:`NAMESPACES`
constant::
>>> xml.ns_tag('dc','author')
'{http://purl.org/dc/elements/1.1/}author'
"""
return "{{{}}}{}".format(NAMESPACES[ns_id], tag)