mwparserfromhell/mwparserfromhell/nodes/html_entity.py

# -*- coding: utf-8  -*-
#
# Copyright (C) 2012 Ben Kurtovic <ben.kurtovic@verizon.net>
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.

import htmlentitydefs

from . import Node

__all__ = ["HTMLEntity"]

class HTMLEntity(Node):
    def __init__(self, value, named=None, hexadecimal=False):
        self._value = value
        if named is None:  # Try to guess whether or not the entity is named
            try:
                int(value)
                self._named = False
                self._hexadecimal = False
            except ValueError:
                try:
                    int(value, 16)
                    self._named = False
                    self._hexadecimal = True
                except ValueError:
                    self._named = True
                    self._hexadecimal = False
        else:
            self._named = named
            self._hexadecimal = hexadecimal

    def __unicode__(self):
        if self.named:
            return u"&{0};".format(self.value)
        if self.hexadecimal:
            return u"&#x{0};".format(self.value)
        return u"&#{0};".format(self.value)

    def __strip__(self, normalize, collapse):
        if normalize:
            return self.normalize()
        return self

    def _unichr(self, value):
        """Implement the builtin unichr() with support for non-BMP code points.

        On wide Python builds, this functions like the normal unichr(). On
        narrow builds, this returns the value's corresponding surrogate pair.
        """
        try:
            return unichr(value)
        except ValueError:
            # Test whether we're on the wide or narrow Python build. Check the
            # length of a non-BMP code point (U+1F64A, SPEAK-NO-EVIL MONKEY):
            if len(u"\U0001F64A") == 2:
                # Ensure this is within the range we can encode:
                if value > 0x10FFFF:
                    raise ValueError("unichr() arg not in range(0x110000)")
                code = value - 0x10000
                if value < 0:  # Invalid code point
                    raise
                lead = 0xD800 + (code >> 10)
                trail = 0xDC00 + (code % (1 << 10))
                return unichr(lead) + unichr(trail)
            raise

    @property
    def value(self):
        return self._value

    @property
    def named(self):
        return self._named

    @property
    def hexadecimal(self):
        return self._hexadecimal

    def normalize(self):
        if self.named:
            return unichr(htmlentitydefs.name2codepoint[self.value])
        if self.hexadecimal:
            return self._unichr(int(self.value, 16))
        return self._unichr(int(self.value))