"""CSSVariables implements (and only partly) experimental
`CSS Variables `_
"""
__all__ = ['CSSVariablesRule']
from .cssvariablesdeclaration import CSSVariablesDeclaration
from . import cssrule
import cssutils
import xml.dom
class CSSVariablesRule(cssrule.CSSRule):
"""
The CSSVariablesRule interface represents a @variables rule within a CSS
style sheet. The @variables rule is used to specify variables.
cssutils uses a :class:`~cssutils.css.CSSVariablesDeclaration` to
represent the variables.
Format::
variables
VARIABLES_SYM S* medium [ COMMA S* medium ]* LBRACE S*
variableset* '}' S*
;
for variableset see :class:`cssutils.css.CSSVariablesDeclaration`
**Media are not implemented. Reason is that cssutils is using CSS
variables in a kind of preprocessing and therefor no media information
is available at this stage. For now do not use media!**
Example::
@variables {
CorporateLogoBGColor: #fe8d12;
}
div.logoContainer {
background-color: var(CorporateLogoBGColor);
}
"""
def __init__(
self,
mediaText=None,
variables=None,
parentRule=None,
parentStyleSheet=None,
readonly=False,
):
"""
If readonly allows setting of properties in constructor only.
"""
super(CSSVariablesRule, self).__init__(
parentRule=parentRule, parentStyleSheet=parentStyleSheet
)
self._atkeyword = '@variables'
# dummy
self._media = cssutils.stylesheets.MediaList(mediaText, readonly=readonly)
if variables:
self.variables = variables
else:
self.variables = CSSVariablesDeclaration(parentRule=self)
self._readonly = readonly
def __repr__(self):
return "cssutils.css.%s(mediaText=%r, variables=%r)" % (
self.__class__.__name__,
self._media.mediaText,
self.variables.cssText,
)
def __str__(self):
return (
""
% (
self.__class__.__name__,
self._media.mediaText,
self.variables.cssText,
self.valid,
id(self),
)
)
def _getCssText(self):
"""Return serialized property cssText."""
return cssutils.ser.do_CSSVariablesRule(self)
def _setCssText(self, cssText):
"""
:exceptions:
- :exc:`~xml.dom.SyntaxErr`:
Raised if the specified CSS string value has a syntax error and
is unparsable.
- :exc:`~xml.dom.InvalidModificationErr`:
Raised if the specified CSS string value represents a different
type of rule than the current one.
- :exc:`~xml.dom.HierarchyRequestErr`:
Raised if the rule cannot be inserted at this point in the
style sheet.
- :exc:`~xml.dom.NoModificationAllowedErr`:
Raised if the rule is readonly.
Format::
variables
: VARIABLES_SYM S* medium [ COMMA S* medium ]* LBRACE S*
variableset* '}' S*
;
variableset
: LBRACE S* vardeclaration [ ';' S* vardeclaration ]* '}' S*
;
"""
super(CSSVariablesRule, self)._setCssText(cssText)
tokenizer = self._tokenize2(cssText)
attoken = self._nexttoken(tokenizer, None)
if self._type(attoken) != self._prods.VARIABLES_SYM:
self._log.error(
'CSSVariablesRule: No CSSVariablesRule found: %s'
% self._valuestr(cssText),
error=xml.dom.InvalidModificationErr,
)
else:
newVariables = CSSVariablesDeclaration(parentRule=self)
ok = True
beforetokens, brace = self._tokensupto2(
tokenizer, blockstartonly=True, separateEnd=True
)
if self._tokenvalue(brace) != '{':
ok = False
self._log.error(
'CSSVariablesRule: No start { of variable '
'declaration found: %r' % self._valuestr(cssText),
brace,
)
# parse stuff before { which should be comments and S only
new = {'wellformed': True}
newseq = self._tempSeq() # []
beforewellformed, expected = self._parse(
expected=':',
seq=newseq,
tokenizer=self._tokenize2(beforetokens),
productions={},
)
ok = ok and beforewellformed and new['wellformed']
variablestokens, braceorEOFtoken = self._tokensupto2(
tokenizer, blockendonly=True, separateEnd=True
)
val, type_ = self._tokenvalue(braceorEOFtoken), self._type(braceorEOFtoken)
if val != '}' and type_ != 'EOF':
ok = False
self._log.error(
'CSSVariablesRule: No "}" after variables '
'declaration found: %r' % self._valuestr(cssText)
)
nonetoken = self._nexttoken(tokenizer)
if nonetoken:
ok = False
self._log.error(
'CSSVariablesRule: Trailing content found.', token=nonetoken
)
if 'EOF' == type_:
# add again as variables needs it
variablestokens.append(braceorEOFtoken)
# SET but may raise:
newVariables.cssText = variablestokens
if ok:
# contains probably comments only upto {
self._setSeq(newseq)
self.variables = newVariables
cssText = property(
_getCssText,
_setCssText,
doc="(DOM) The parsable textual representation of this " "rule.",
)
media = property(
doc="NOT IMPLEMENTED! As cssutils resolves variables "
"during serializing media information is lost."
)
def _setVariables(self, variables):
"""
:param variables:
a CSSVariablesDeclaration or string
"""
self._checkReadonly()
if isinstance(variables, str):
self._variables = CSSVariablesDeclaration(
cssText=variables, parentRule=self
)
else:
variables._parentRule = self
self._variables = variables
variables = property(
lambda self: self._variables,
_setVariables,
doc="(DOM) The variables of this rule set, a "
":class:`cssutils.css.CSSVariablesDeclaration`.",
)
type = property(
lambda self: self.VARIABLES_RULE,
doc="The type of this rule, as defined by a CSSRule " "type constant.",
)
valid = property(lambda self: True, doc='NOT IMPLEMTED REALLY (TODO)')
# constant but needed:
wellformed = property(lambda self: True)