"""base classes and helper functions for css and stylesheets packages"""

__all__ = []

import codecs

import re

import xml.dom

from itertools import chain

import cssutils

from . import codec, errorhandler, tokenize2

from .helper import normalize

try:

from ._fetchgae import _defaultFetcher

except ImportError:

from ._fetch import _defaultFetcher

log = errorhandler.ErrorHandler()

class _BaseClass:

"""

Base class for Base, Base2 and _NewBase.

**Base and Base2 will be removed in the future!**

"""

_log = errorhandler.ErrorHandler()

_prods = tokenize2.CSSProductions

def _checkReadonly(self):

"Raise xml.dom.NoModificationAllowedErr if rule/... is readonly"

if hasattr(self, '_readonly') and self._readonly:

raise xml.dom.NoModificationAllowedErr('%s is readonly.' % self.__class__)

return True

return False

def _valuestr(self, t):

"""

Return string value of t (t may be a string, a list of token tuples

or a single tuple in format (type, value, line, col).

Mainly used to get a string value of t for error messages.

"""

if not t:

return ''

elif isinstance(t, str):

return t

else:

return ''.join([x[1] for x in t])

class _NewBase(_BaseClass):

"""

New base class for classes using ProdParser.

**Currently CSSValue and related ones only.**

"""

def __init__(self):

self._seq = Seq()

def _setSeq(self, newseq):

"""Set value of ``seq`` which is readonly."""

newseq._readonly = True

self._seq = newseq

def _clearSeq(self):

self._seq.clear()

def _tempSeq(self, readonly=False):

"Get a writeable Seq() which is used to set ``seq`` later"

return Seq(readonly=readonly)

@property

def seq(self):

"""Internal readonly attribute, **DO NOT USE**!"""

return self._seq

class _NewListBase(_NewBase):

"""

(EXPERIMENTAL)

A base class used for list classes like stylesheets.MediaList

adds list like behaviour running on inhering class' property ``seq``

- item in x => bool

- len(x) => integer

- get, set and del x[i]

- for item in x

- append(item)

some methods must be overwritten in inheriting class

"""

def __init__(self):

self._seq = Seq()

def __contains__(self, item):

for it in self._seq:

if item == it.value:

return True

return False

def __delitem__(self, index):

del self._seq[index]

def __getitem__(self, index):

return self._seq[index].value

def __iter__(self):

def gen():

for x in self._seq:

yield x.value

return gen()

def __len__(self):

return len(self._seq)

def __setitem__(self, index, item):

"must be overwritten"

raise NotImplementedError

def append(self, item):

"must be overwritten"

raise NotImplementedError

class Base(_BaseClass):

"""

**Superceded by _NewBase**

**Superceded by Base2 which is used for new seq handling class.**

Base class for most CSS and StyleSheets classes

Contains helper methods for inheriting classes helping parsing

``_normalize`` is static as used by Preferences.

"""

__tokenizer2 = tokenize2.Tokenizer()

# for more on shorthand properties see

# http://www.dustindiaz.com/css-shorthand/

# format: shorthand: [(propname, mandatorycheck?)*]

_SHORTHANDPROPERTIES = {

'background': [],

# u'background-position': [], # list of 2 values!

'border': [],

'border-left': [],

'border-right': [],

'border-top': [],

'border-bottom': [],

# u'border-color': [], # list or single but same values

# u'border-style': [], # list or single but same values

# u'border-width': [], # list or single but same values

'cue': [],

'font': [],

'list-style': [],

# u'margin': [], # list or single but same values

'outline': [],

# u'padding': [], # list or single but same values

'pause': [],

}

@staticmethod

def _normalize(x):

r"""

normalizes x, namely:

- remove any \ before non unicode sequences (0-9a-zA-Z) so for

x=="c\olor\" return "color" (unicode escape sequences should have

been resolved by the tokenizer already)

- lowercase

"""

return normalize(x)

def _splitNamespacesOff(self, text_namespaces_tuple):

"""

returns tuple (text, dict-of-namespaces) or if no namespaces are

in cssText returns (cssText, {})

used in Selector, SelectorList, CSSStyleRule, CSSMediaRule and

CSSStyleSheet

"""

if isinstance(text_namespaces_tuple, tuple):

return text_namespaces_tuple[0], _SimpleNamespaces(

self._log, text_namespaces_tuple[1]

)

else:

return text_namespaces_tuple, _SimpleNamespaces(log=self._log)

def _tokenize2(self, textortokens):

"""

returns tokens of textortokens which may already be tokens in which

case simply returns input

"""

if not textortokens:

return None

elif isinstance(textortokens, str):

# needs to be tokenized

return self.__tokenizer2.tokenize(textortokens)

elif isinstance(textortokens, tuple):

# a single token (like a comment)

return [textortokens]

else:

# already tokenized but return an iterator

return iter(textortokens)

def _nexttoken(self, tokenizer, default=None):

"returns next token in generator tokenizer or the default value"

try:

return next(tokenizer)

# TypeError for py3

except (StopIteration, AttributeError, TypeError):

return default

def _type(self, token):

"returns type of Tokenizer token"

if token:

return token[0]

else:

return None

def _tokenvalue(self, token, normalize=False):

"returns value of Tokenizer token"

if token and normalize:

return Base._normalize(token[1])

elif token:

return token[1]

else:

return None

def _stringtokenvalue(self, token):

"""

for STRING returns the actual content without surrounding "" or ''

and without respective escapes, e.g.::

"with \" char" => with " char

"""

if token:

value = token[1]

return value.replace('\\' + value[0], value[0])[1:-1]

else:

return None

def _uritokenvalue(self, token):

"""

for URI returns the actual content without surrounding url()

or url(""), url('') and without respective escapes, e.g.::

url("\"") => "

"""

if token:

value = token[1][4:-1].strip()

if value and (value[0] in '\'"') and (value[0] == value[-1]):

# a string "..." or '...'

value = value.replace('\\' + value[0], value[0])[1:-1]

return value

else:

return None

def _tokensupto2( # noqa: C901

self,

tokenizer,

starttoken=None,

blockstartonly=False, # {

blockendonly=False, # }

mediaendonly=False,

importmediaqueryendonly=False, # ; or STRING

mediaqueryendonly=False, # { or STRING

semicolon=False, # ;

propertynameendonly=False, # :

propertyvalueendonly=False, # ! ; }

propertypriorityendonly=False, # ; }

selectorattendonly=False, # ]

funcendonly=False, # )

listseponly=False, # ,

separateEnd=False, # returns (resulttokens, endtoken)

):

"""

returns tokens upto end of atrule and end index

end is defined by parameters, might be ; } ) or other

default looks for ending "}" and ";"

"""

ends = ';}'

endtypes = ()

brace = bracket = parant = 0 # {}, [], ()

if blockstartonly: # {

ends = '{'

brace = -1 # set to 0 with first {

elif blockendonly: # }

ends = '}'

brace = 1

elif mediaendonly: # }

ends = '}'

brace = 1 # rules } and mediarules }

elif importmediaqueryendonly:

# end of mediaquery which may be ; or STRING

ends = ';'

endtypes = ('STRING',)

elif mediaqueryendonly:

# end of mediaquery which may be { or STRING

# special case, see below

ends = '{'

brace = -1 # set to 0 with first {

endtypes = ('STRING',)

elif semicolon:

ends = ';'

elif propertynameendonly: # : and ; in case of an error

ends = ':;'

elif propertyvalueendonly: # ; or !important

ends = ';!'

elif propertypriorityendonly: # ;

ends = ';'

elif selectorattendonly: # ]

ends = ']'

if starttoken and self._tokenvalue(starttoken) == '[':

bracket = 1

elif funcendonly: # )

ends = ')'

parant = 1

elif listseponly: # ,

ends = ','

resulttokens = []

if starttoken:

resulttokens.append(starttoken)

val = starttoken[1]

if '[' == val:

bracket += 1

elif '{' == val:

brace += 1

elif '(' == val:

parant += 1

if tokenizer:

for token in tokenizer:

typ, val, line, col = token

if 'EOF' == typ:

resulttokens.append(token)

break

if '{' == val:

brace += 1

elif '}' == val:

brace -= 1

elif '[' == val:

bracket += 1

elif ']' == val:

bracket -= 1

# function( or single (

elif '(' == val or Base._prods.FUNCTION == typ:

parant += 1

elif ')' == val:

parant -= 1

resulttokens.append(token)

if (brace == bracket == parant == 0) and (

val in ends or typ in endtypes

):

break

elif (

mediaqueryendonly

and brace == -1

and (bracket == parant == 0)

and typ in endtypes

):

# mediaqueryendonly with STRING

break

if separateEnd:

# TODO: use this method as generator, then this makes sense

if resulttokens:

return resulttokens[:-1], resulttokens[-1]

else:

return resulttokens, None

else:

return resulttokens

def _adddefaultproductions(self, productions, new=None):

"""

adds default productions if not already present, used by

_parse only

each production should return the next expected token

normaly a name like "uri" or "EOF"

some have no expectation like S or COMMENT, so simply return

the current value of self.__expected

"""

def ATKEYWORD(expected, seq, token, tokenizer=None):

"default impl for unexpected @rule"

if expected != 'EOF':

# TODO: parentStyleSheet=self

rule = cssutils.css.CSSUnknownRule()

rule.cssText = self._tokensupto2(tokenizer, token)

if rule.wellformed:

seq.append(rule)

return expected

else:

new['wellformed'] = False

self._log.error('Expected EOF.', token=token)

return expected

def COMMENT(expected, seq, token, tokenizer=None):

"default implementation for COMMENT token adds CSSCommentRule"

seq.append(cssutils.css.CSSComment([token]))

return expected

def S(expected, seq, token, tokenizer=None):

"default implementation for S token, does nothing"

return expected

def EOF(expected=None, seq=None, token=None, tokenizer=None):

"default implementation for EOF token"

return 'EOF'

p = {

'ATKEYWORD': ATKEYWORD,

'COMMENT': COMMENT,

'S': S,

'EOF': EOF, # only available if fullsheet

}

p.update(productions)

return p

def _parse(

self,

expected,

seq,

tokenizer,

productions,

default=None,

new=None,

initialtoken=None,

):

"""

puts parsed tokens in seq by calling a production with

(seq, tokenizer, token)

expected

a name what token or value is expected next, e.g. 'uri'

seq

to add rules etc to

tokenizer

call tokenizer.next() to get next token

productions

callbacks {tokentype: callback}

default

default callback if tokentype not in productions

new

used to init default productions

initialtoken

will be used together with tokenizer running 1st this token

and then all tokens in tokenizer

returns (wellformed, expected) which the last prod might have set

"""

wellformed = True

if initialtoken:

# add initialtoken to tokenizer

def tokens():

"Build new tokenizer including initialtoken"

yield initialtoken

yield from tokenizer

fulltokenizer = chain([initialtoken], tokenizer)

else:

fulltokenizer = tokenizer

if fulltokenizer:

prods = self._adddefaultproductions(productions, new)

for token in fulltokenizer:

p = prods.get(token[0], default)

if p:

expected = p(expected, seq, token, tokenizer)

else:

wellformed = False

self._log.error('Unexpected token (%s, %s, %s, %s)' % token)

return wellformed, expected

class Base2(Base, _NewBase):

"""

**Superceded by _NewBase.**

Base class for new seq handling.

"""

def __init__(self):

self._seq = Seq()

def _adddefaultproductions(self, productions, new=None):

"""

adds default productions if not already present, used by

_parse only

each production should return the next expected token

normaly a name like "uri" or "EOF"

some have no expectation like S or COMMENT, so simply return

the current value of self.__expected

"""

def ATKEYWORD(expected, seq, token, tokenizer=None):

"default impl for unexpected @rule"

if expected != 'EOF':

# TODO: parentStyleSheet=self

rule = cssutils.css.CSSUnknownRule()

rule.cssText = self._tokensupto2(tokenizer, token)

if rule.wellformed:

seq.append(

rule,

cssutils.css.CSSRule.UNKNOWN_RULE,

line=token[2],

col=token[3],

)

return expected

else:

new['wellformed'] = False

self._log.error('Expected EOF.', token=token)

return expected

def COMMENT(expected, seq, token, tokenizer=None):

"default impl, adds CSSCommentRule if not token == EOF"

if expected == 'EOF':

new['wellformed'] = False

self._log.error('Expected EOF but found comment.', token=token)

seq.append(cssutils.css.CSSComment([token]), 'COMMENT')

return expected

def S(expected, seq, token, tokenizer=None):

"default impl, does nothing if not token == EOF"

if expected == 'EOF':

new['wellformed'] = False

self._log.error('Expected EOF but found whitespace.', token=token)

return expected

def EOF(expected=None, seq=None, token=None, tokenizer=None):

"default implementation for EOF token"

return 'EOF'

defaultproductions = {

'ATKEYWORD': ATKEYWORD,

'COMMENT': COMMENT,

'S': S,

'EOF': EOF, # only available if fullsheet

}

defaultproductions.update(productions)

return defaultproductions

class Seq:

"""

property seq of Base2 inheriting classes, holds a list of Item objects.

used only by Selector for now

is normally readonly, only writable during parsing

"""

def __init__(self, readonly=True):

"""

only way to write to a Seq is to initialize it with new items

each itemtuple has (value, type, line) where line is optional

"""

self._seq = []

self._readonly = readonly

def __repr__(self):

"returns a repr same as a list of tuples of (value, type)"

return 'cssutils.{}.{}([\n {}], readonly={!r})'.format(

self.__module__,

self.__class__.__name__,

',\n '.join(['%r' % item for item in self._seq]),

self._readonly,

)

def __str__(self):

vals = []

for v in self:

if isinstance(v.value, str):

vals.append(v.value)

elif isinstance(v, tuple):

vals.append(v.value[1])

else:

vals.append(repr(v))

return f"<cssutils.{self.__module__}.{self.__class__.__name__} object length={len(self)!r} items={vals!r} readonly={self._readonly!r} at 0x{id(self):x}>"

def __delitem__(self, i):

del self._seq[i]

def __getitem__(self, i):

return self._seq[i]

def __setitem__(self, i, xxx_todo_changeme):

(val, typ, line, col) = xxx_todo_changeme

self._seq[i] = Item(val, typ, line, col)

def __iter__(self):

return iter(self._seq)

def __len__(self):

return len(self._seq)

def append(self, val, typ=None, line=None, col=None):

"If not readonly add new Item()"

if self._readonly:

raise AttributeError('Seq is readonly.')

else:

if isinstance(val, Item):

self._seq.append(val)

else:

self._seq.append(Item(val, typ, line, col))

def appendItem(self, item):

"if not readonly add item which must be an Item"

if self._readonly:

raise AttributeError('Seq is readonly.')

else:

self._seq.append(item)

def clear(self):

del self._seq[:]

def insert(self, index, val, typ, line=None, col=None):

"Insert new Item() at index # even if readony!? TODO!"

self._seq.insert(index, Item(val, typ, line, col))

def replace(self, index=-1, val=None, typ=None, line=None, col=None):

"""

if not readonly replace Item at index with new Item or

simply replace value or type

"""

if self._readonly:

raise AttributeError('Seq is readonly.')

else:

self._seq[index] = Item(val, typ, line, col)

def rstrip(self):

"trims S items from end of Seq"

while self._seq and self._seq[-1].type == tokenize2.CSSProductions.S:

# TODO: removed S before CSSComment /**/ /**/

del self._seq[-1]

def appendToVal(self, val=None, index=-1):

"""

if not readonly append to Item's value at index

"""

if self._readonly:

raise AttributeError('Seq is readonly.')

else:

old = self._seq[index]

self._seq[index] = Item(old.value + val, old.type, old.line, old.col)

class Item:

"""

an item in the seq list of classes (successor to tuple items in old seq)

each item has attributes:

type

a sematic type like "element", "attribute"

value

the actual value which may be a string, number etc or an instance

of e.g. a CSSComment

*line*

**NOT IMPLEMENTED YET, may contain the line in the source later**

"""

def __init__(self, value, type, line=None, col=None):

self.__value = value

self.__type = type

self.__line = line

self.__col = col

type = property(lambda self: self.__type)

value = property(lambda self: self.__value)

line = property(lambda self: self.__line)

col = property(lambda self: self.__col)

def __repr__(self):

return f"{self.__module__}.{self.__class__.__name__}(value={self.__value!r}, type={self.__type!r}, line={self.__line!r}, col={self.__col!r})"

class ListSeq:

"""

(EXPERIMENTAL)

A base class used for list classes like cssutils.css.SelectorList or

stylesheets.MediaList

adds list like behaviour running on inhering class' property ``seq``

- item in x => bool

- len(x) => integer

- get, set and del x[i]

- for item in x

- append(item)

some methods must be overwritten in inheriting class

"""

def __init__(self):

self.seq = [] # does not need to use ``Seq`` as simple list only

def __contains__(self, item):

return item in self.seq

def __delitem__(self, index):

del self.seq[index]

def __getitem__(self, index):

return self.seq[index]

def __iter__(self):

def gen():

yield from self.seq

return gen()

def __len__(self):

return len(self.seq)

def __setitem__(self, index, item):

"must be overwritten"

raise NotImplementedError

def append(self, item):

"must be overwritten"

raise NotImplementedError

class _Namespaces:

"""

A dictionary like wrapper for @namespace rules used in a CSSStyleSheet.

Works on effective namespaces, so e.g. if::

@namespace p1 "uri";

@namespace p2 "uri";

only the second rule is effective and kept.

namespaces

a dictionary {prefix: namespaceURI} containing the effective namespaces

only. These are the latest set in the CSSStyleSheet.

parentStyleSheet

the parent CSSStyleSheet

"""

def __init__(self, parentStyleSheet, log=None, *args):

"no initial values are set, only the relevant sheet is"

self.parentStyleSheet = parentStyleSheet

self._log = log

def __repr__(self):

return "%r" % self.namespaces

def __contains__(self, prefix):

return prefix in self.namespaces

def __delitem__(self, prefix):

"""deletes CSSNamespaceRule(s) with rule.prefix == prefix

prefix '' and None are handled the same

"""

if not prefix:

prefix = ''

delrule = self.__findrule(prefix)

for i, rule in enumerate(

filter(lambda r: r.type == r.NAMESPACE_RULE, self.parentStyleSheet.cssRules)

):

if rule == delrule:

self.parentStyleSheet.deleteRule(i)

return

self._log.error('Prefix %s not found.' % prefix, error=xml.dom.NamespaceErr)

def __getitem__(self, prefix):

try:

return self.namespaces[prefix]

except KeyError:

self._log.error('Prefix %s not found.' % prefix, error=xml.dom.NamespaceErr)

def __iter__(self):

return self.namespaces.__iter__()

def __len__(self):

return len(self.namespaces)

def __setitem__(self, prefix, namespaceURI):

"replaces prefix or sets new rule, may raise NoModificationAllowedErr"

if not prefix:

prefix = '' # None or ''

rule = self.__findrule(prefix)

if not rule:

self.parentStyleSheet.insertRule(

cssutils.css.CSSNamespaceRule(prefix=prefix, namespaceURI=namespaceURI),

inOrder=True,

)

else:

if prefix in self.namespaces:

rule.namespaceURI = namespaceURI # raises NoModificationAllowedErr

if namespaceURI in list(self.namespaces.values()):

rule.prefix = prefix

def __findrule(self, prefix):

# returns namespace rule where prefix == key

for rule in filter(

lambda r: r.type == r.NAMESPACE_RULE,

reversed(self.parentStyleSheet.cssRules),

):

if rule.prefix == prefix:

return rule

@property

def namespaces(self):

"""

A property holding only effective @namespace rules in

self.parentStyleSheets.

"""

namespaces = {}

for rule in filter(

lambda r: r.type == r.NAMESPACE_RULE,

reversed(self.parentStyleSheet.cssRules),

):

if rule.namespaceURI not in list(namespaces.values()):

namespaces[rule.prefix] = rule.namespaceURI

return namespaces

def get(self, prefix, default):

return self.namespaces.get(prefix, default)

def items(self):

return list(self.namespaces.items())

def keys(self):

return list(self.namespaces.keys())

def values(self):

return list(self.namespaces.values())

def prefixForNamespaceURI(self, namespaceURI):

"""

returns effective prefix for given namespaceURI or raises IndexError

if this cannot be found"""

for prefix, uri in list(self.namespaces.items()):

if uri == namespaceURI:

return prefix

raise IndexError('NamespaceURI %s not found.' % namespaceURI)

def __str__(self):

return f"<cssutils.util.{self.__class__.__name__} object parentStyleSheet={str(self.parentStyleSheet)!r} at 0x{id(self):x}>"

class _SimpleNamespaces(_Namespaces):

"""

namespaces used in objects like Selector as long as they are not connected

to a CSSStyleSheet

"""

def __init__(self, log=None, *args):

"""init"""

super().__init__(parentStyleSheet=None, log=log)

self.__namespaces = dict(*args)

def __setitem__(self, prefix, namespaceURI):

self.__namespaces[prefix] = namespaceURI

@property

def namespaces(self):

"""Dict Wrapper for self.sheets @namespace rules."""

return self.__namespaces

def __str__(self):

return f"<cssutils.util.{self.__class__.__name__} object namespaces={self.namespaces!r} at 0x{id(self):x}>"

def __repr__(self):

return f"cssutils.util.{self.__class__.__name__}({self.namespaces!r})"

def _readUrl( # noqa: C901

url, fetcher=None, overrideEncoding=None, parentEncoding=None

):

"""

Read cssText from url and decode it using all relevant methods (HTTP

header, BOM, @charset). Returns

- encoding used to decode text (which is needed to set encoding of

stylesheet properly)

- type of encoding (how it was retrieved, see list below)

- decodedCssText

``fetcher``

see cssutils.CSSParser.setFetcher for details

``overrideEncoding``

If given this encoding is used and all other encoding information is

ignored (HTTP, BOM etc)

``parentEncoding``

Encoding of parent stylesheet (while e.g. reading @import references

sheets) or document if available.

Priority or encoding information

--------------------------------

**cssutils only**: 0. overrideEncoding

1. An HTTP "charset" parameter in a "Content-Type" field (or similar

parameters in other protocols)

2. BOM and/or @charset (see below)

3. <link charset=""> or other metadata from the linking mechanism (if any)

4. charset of referring style sheet or document (if any)

5. Assume UTF-8

"""

enctype = None

if not fetcher:

fetcher = _defaultFetcher

r = fetcher(url)

if r and len(r) == 2 and r[1] is not None:

httpEncoding, content = r

if overrideEncoding:

enctype = 0 # 0. override encoding

encoding = overrideEncoding

elif httpEncoding:

enctype = 1 # 1. HTTP

encoding = httpEncoding

else:

# BOM or @charset

if isinstance(content, str):

contentEncoding, explicit = codec.detectencoding_unicode(content)

else:

contentEncoding, explicit = codec.detectencoding_str(content)

if explicit:

enctype = 2 # 2. BOM/@charset: explicitly

encoding = contentEncoding

elif parentEncoding:

enctype = 4 # 4. parent stylesheet or document

# may also be None in which case 5. is used in next step anyway

encoding = parentEncoding

else:

enctype = 5 # 5. assume UTF-8

encoding = 'utf-8'

if isinstance(content, str):

decodedCssText = content

else:

try:

# encoding may still be wrong if encoding *is lying*!

try:

decodedCssText = codecs.lookup("css")[1](

content, encoding=encoding

)[0]

except AttributeError:

# at least in GAE

decodedCssText = content.decode(encoding if encoding else 'utf-8')

except UnicodeDecodeError as e:

log.warn(e, neverraise=True)

decodedCssText = None

return encoding, enctype, decodedCssText

else:

return None, None, None

class LazyRegex:

"""A class to represent a lazily compiled regular expression.

The interface is kept similar to a `re.compile`ed object from the standard

regex library.

:ivar pattern: The original regular expression.

:ivar flags: Flags of the regular expression.

:ivar matcher: The compiled regular expression, or None if it is not yet

compiled.

:ivar groups: The number of capturing groups in the pattern, or None.

:ivar groupindex: A dictionary mapping any symbolic group names defined by

`(?P<id>)` to group numbers. The dictionary is empty if

no symbolic groups were used in the pattern. None if the

pattern is not yet compiled.

"""

__slots__ = ('pattern', 'flags', 'matcher', 'groups', 'groupindex')

def __init__(self, pattern, flags=0):

self.pattern = pattern