debian-python-tinycss2/tinycss2/serializer.py

123 lines
3.6 KiB
Python

from __future__ import unicode_literals
def serialize(nodes):
"""Serialize nodes to CSS syntax.
This should be used for :term:`component values`
instead of just :meth:`~tinycss2.ast.Node.serialize` on each node
as it takes care of corner cases such as ``;`` between declarations,
and consecutive identifiers
that would otherwise parse back as the same token.
:param nodes: an iterable of :class:`~tinycss2.ast.Node` objects
:returns: an Unicode string
"""
chunks = []
_serialize_to(nodes, chunks.append)
return ''.join(chunks)
def serialize_identifier(value):
"""Serialize any string as a CSS identifier
:param value: a :term:`string`
:returns:
an Unicode string
that would parse as an :class:`~tinycss2.ast.IdentToken`
whose :attr:`~tinycss2.ast.IdentToken.value` attribute
equals the passed :obj:`value` argument.
"""
if value == '-':
return r'\-'
if value[0] == '-':
result = '-'
value = value[1:]
else:
result = ''
c = value[0]
result += (
c if c in ('abcdefghijklmnopqrstuvwxyz_'
'ABCDEFGHIJKLMNOPQRSTUVWXYZ') or ord(c) > 0x7F else
r'\A ' if c == '\n' else
r'\D ' if c == '\r' else
r'\C ' if c == '\f' else
'\\%X ' % ord(c) if c in '0123456789' else
'\\' + c
)
result += serialize_name(value[1:])
return result
def serialize_name(value):
return ''.join(
c if c in ('abcdefghijklmnopqrstuvwxyz-_0123456789'
'ABCDEFGHIJKLMNOPQRSTUVWXYZ') or ord(c) > 0x7F else
r'\A ' if c == '\n' else
r'\D ' if c == '\r' else
r'\C ' if c == '\f' else
'\\' + c
for c in value
)
def serialize_string_value(value):
return ''.join(
r'\"' if c == '"' else
r'\\' if c == '\\' else
r'\A ' if c == '\n' else
r'\D ' if c == '\r' else
r'\C ' if c == '\f' else
c
for c in value
)
# http://dev.w3.org/csswg/css-syntax/#serialization-tables
def _serialize_to(nodes, write):
"""Serialize an iterable of nodes to CSS syntax,
writing chunks as Unicode string
by calling the provided :obj:`write` callback.
"""
bad_pairs = BAD_PAIRS
previous_type = None
for node in nodes:
serialization_type = (node.type if node.type != 'literal'
else node.value)
if (previous_type, serialization_type) in bad_pairs:
write('/**/')
elif previous_type == '\\' and not (
serialization_type == 'whitespace' and
node.value.startswith('\n')):
write('\n')
node._serialize_to(write)
if serialization_type == 'declaration':
write(';')
previous_type = serialization_type
BAD_PAIRS = set(
[(a, b)
for a in ('ident', 'at-keyword', 'hash', 'dimension', '#', '-',
'number')
for b in ('ident', 'function', 'url', 'number', 'percentage',
'dimension', 'unicode-range')] +
[(a, b)
for a in ('ident', 'at-keyword', 'hash', 'dimension')
for b in ('-', '-->')] +
[(a, b)
for a in ('#', '-', 'number', '@')
for b in ('ident', 'function', 'url')] +
[(a, b)
for a in ('unicode-range', '.', '+')
for b in ('number', 'percentage', 'dimension')] +
[('@', b) for b in ('ident', 'function', 'url', 'unicode-range', '-')] +
[('unicode-range', b) for b in ('ident', 'function', '?')] +
[(a, '=') for a in '$*^~|'] +
[('ident', '() block'), ('|', '|'), ('/', '*')]
)