"""CSSStyleDeclaration implements DOM Level 2 CSS CSSStyleDeclaration and extends CSS2Properties see http://www.w3.org/TR/1998/REC-CSS2-19980512/syndata.html#parsing-errors Unknown properties ------------------ User agents must ignore a declaration with an unknown property. For example, if the style sheet is:: H1 { color: red; rotation: 70minutes } the user agent will treat this as if the style sheet had been:: H1 { color: red } Cssutils gives a message about any unknown properties but keeps any property (if syntactically correct). Illegal values -------------- User agents must ignore a declaration with an illegal value. For example:: IMG { float: left } /* correct CSS2 */ IMG { float: left here } /* "here" is not a value of 'float' */ IMG { background: "red" } /* keywords cannot be quoted in CSS2 */ IMG { border-width: 3 } /* a unit must be specified for length values */ A CSS2 parser would honor the first rule and ignore the rest, as if the style sheet had been:: IMG { float: left } IMG { } IMG { } IMG { } Cssutils again will issue a message (WARNING in this case) about invalid CSS2 property values. TODO: This interface is also used to provide a read-only access to the computed values of an element. See also the ViewCSS interface. - return computed values and not literal values - simplify unit pairs/triples/quadruples 2px 2px 2px 2px -> 2px for border/padding... - normalize compound properties like: background: no-repeat left url() #fff -> background: #fff url() no-repeat left """ __all__ = ['CSSStyleDeclaration', 'Property'] __docformat__ = 'restructuredtext' __version__ = '$Id$' from cssproperties import CSS2Properties from property import Property import cssutils import xml.dom class CSSStyleDeclaration(CSS2Properties, cssutils.util.Base2): """The CSSStyleDeclaration class represents a single CSS declaration block. This class may be used to determine the style properties currently set in a block or to set style properties explicitly within the block. While an implementation may not recognize all CSS properties within a CSS declaration block, it is expected to provide access to all specified properties in the style sheet through the CSSStyleDeclaration interface. Furthermore, implementations that support a specific level of CSS should correctly handle CSS shorthand properties for that level. For a further discussion of shorthand properties, see the CSS2Properties interface. Additionally the CSS2Properties interface is implemented. $css2propertyname All properties defined in the CSS2Properties class are available as direct properties of CSSStyleDeclaration with their respective DOM name, so e.g. ``fontStyle`` for property 'font-style'. These may be used as:: >>> style = CSSStyleDeclaration(cssText='color: red') >>> style.color = 'green' >>> print style.color green >>> del style.color >>> print style.color Format:: [Property: Value Priority?;]* [Property: Value Priority?]? """ def __init__(self, cssText=u'', parentRule=None, readonly=False, validating=None): """ :param cssText: Shortcut, sets CSSStyleDeclaration.cssText :param parentRule: The CSS rule that contains this declaration block or None if this CSSStyleDeclaration is not attached to a CSSRule. :param readonly: defaults to False :param validating: a flag defining if this sheet should be validated on change. Defaults to None, which means defer to the parent stylesheet. """ super(CSSStyleDeclaration, self).__init__() self._parentRule = parentRule self.validating = validating self.cssText = cssText self._readonly = readonly def __contains__(self, nameOrProperty): """Check if a property (or a property with given name) is in style. :param name: a string or Property, uses normalized name and not literalname """ if isinstance(nameOrProperty, Property): name = nameOrProperty.name else: name = self._normalize(nameOrProperty) return name in self.__nnames() def __iter__(self): """Iterator of set Property objects with different normalized names.""" def properties(): for name in self.__nnames(): yield self.getProperty(name) return properties() def keys(self): """Analoguous to standard dict returns property names which are set in this declaration.""" return list(self.__nnames()) def __getitem__(self, CSSName): """Retrieve the value of property ``CSSName`` from this declaration. ``CSSName`` will be always normalized. """ return self.getPropertyValue(CSSName) def __setitem__(self, CSSName, value): """Set value of property ``CSSName``. ``value`` may also be a tuple of (value, priority), e.g. style['color'] = ('red', 'important') ``CSSName`` will be always normalized. """ priority = None if isinstance(value, tuple): value, priority = value return self.setProperty(CSSName, value, priority) def __delitem__(self, CSSName): """Delete property ``CSSName`` from this declaration. If property is not in this declaration return u'' just like removeProperty. ``CSSName`` will be always normalized. """ return self.removeProperty(CSSName) def __setattr__(self, n, v): """Prevent setting of unknown properties on CSSStyleDeclaration which would not work anyway. For these ``CSSStyleDeclaration.setProperty`` MUST be called explicitly! TODO: implementation of known is not really nice, any alternative? """ known = ['_tokenizer', '_log', '_ttypes', '_seq', 'seq', 'parentRule', '_parentRule', 'cssText', 'valid', 'wellformed', 'validating', '_readonly', '_profiles', '_validating'] known.extend(CSS2Properties._properties) if n in known: super(CSSStyleDeclaration, self).__setattr__(n, v) else: raise AttributeError(u'Unknown CSS Property, ' u'``CSSStyleDeclaration.setProperty("%s", ' u'...)`` MUST be used.' % n) def __repr__(self): return u"cssutils.css.%s(cssText=%r)" % ( self.__class__.__name__, self.getCssText(separator=u' ')) def __str__(self): return u"" % ( self.__class__.__name__, self.length, len(self.getProperties(all=True)), id(self)) def __nnames(self): """Return iterator for all different names in order as set if names are set twice the last one is used (double reverse!) """ names = [] for item in reversed(self.seq): val = item.value if isinstance(val, Property) and not val.name in names: names.append(val.name) return reversed(names) # overwritten accessor functions for CSS2Properties' properties def _getP(self, CSSName): """(DOM CSS2Properties) Overwritten here and effectively the same as ``self.getPropertyValue(CSSname)``. Parameter is in CSSname format ('font-style'), see CSS2Properties. Example:: >>> style = CSSStyleDeclaration(cssText='font-style:italic;') >>> print style.fontStyle italic """ return self.getPropertyValue(CSSName) def _setP(self, CSSName, value): """(DOM CSS2Properties) Overwritten here and effectively the same as ``self.setProperty(CSSname, value)``. Only known CSS2Properties may be set this way, otherwise an AttributeError is raised. For these unknown properties ``setPropertyValue(CSSname, value)`` has to be called explicitly. Also setting the priority of properties needs to be done with a call like ``setPropertyValue(CSSname, value, priority)``. Example:: >>> style = CSSStyleDeclaration() >>> style.fontStyle = 'italic' >>> # or >>> style.setProperty('font-style', 'italic', '!important') """ self.setProperty(CSSName, value) # TODO: Shorthand ones def _delP(self, CSSName): """(cssutils only) Overwritten here and effectively the same as ``self.removeProperty(CSSname)``. Example:: >>> style = CSSStyleDeclaration(cssText='font-style:italic;') >>> del style.fontStyle >>> print style.fontStyle """ self.removeProperty(CSSName) def children(self): """Generator yielding any known child in this declaration including *all* properties, comments or CSSUnknownrules. """ for item in self._seq: yield item.value def _getCssText(self): """Return serialized property cssText.""" return cssutils.ser.do_css_CSSStyleDeclaration(self) def _setCssText(self, cssText): """Setting this attribute will result in the parsing of the new value and resetting of all the properties in the declaration block including the removal or addition of properties. :exceptions: - :exc:`~xml.dom.NoModificationAllowedErr`: Raised if this declaration is readonly or a property is readonly. - :exc:`~xml.dom.SyntaxErr`: Raised if the specified CSS string value has a syntax error and is unparsable. """ self._checkReadonly() tokenizer = self._tokenize2(cssText) # for closures: must be a mutable new = {'wellformed': True} def ident(expected, seq, token, tokenizer=None): # a property tokens = self._tokensupto2(tokenizer, starttoken=token, semicolon=True) if self._tokenvalue(tokens[-1]) == u';': tokens.pop() property = Property(parent=self) property.cssText = tokens if property.wellformed: seq.append(property, 'Property') else: self._log.error(u'CSSStyleDeclaration: Syntax Error in ' u'Property: %s' % self._valuestr(tokens)) # does not matter in this case return expected def unexpected(expected, seq, token, tokenizer=None): # error, find next ; or } to omit upto next property ignored = self._tokenvalue(token) + self._valuestr( self._tokensupto2(tokenizer, propertyvalueendonly=True)) self._log.error(u'CSSStyleDeclaration: Unexpected token, ignoring ' 'upto %r.' % ignored,token) # does not matter in this case return expected def char(expected, seq, token, tokenizer=None): # a standalone ; or error... if self._tokenvalue(token) == u';': self._log.info(u'CSSStyleDeclaration: Stripped standalone semicolon' u': %s' % self._valuestr([token]), neverraise=True) return expected else: return unexpected(expected, seq, token, tokenizer) # [Property: Value;]* Property: Value? newseq = self._tempSeq() wellformed, expected = self._parse(expected=None, seq=newseq, tokenizer=tokenizer, productions={'IDENT': ident, 'CHAR': char}, default=unexpected) # wellformed set by parse for item in newseq: item.value._parent = self # do not check wellformed as invalid things are removed anyway self._setSeq(newseq) cssText = property(_getCssText, _setCssText, doc=u"(DOM) A parsable textual representation of the " u"declaration block excluding the surrounding curly " u"braces.") def getCssText(self, separator=None): """ :returns: serialized property cssText, each property separated by given `separator` which may e.g. be ``u''`` to be able to use cssText directly in an HTML style attribute. ``;`` is part of each property (except the last one) and **cannot** be set with separator! """ return cssutils.ser.do_css_CSSStyleDeclaration(self, separator) def _setParentRule(self, parentRule): self._parentRule = parentRule # for x in self.children(): # x.parent = self parentRule = property(lambda self: self._parentRule, _setParentRule, doc="(DOM) The CSS rule that contains this declaration block or " "None if this CSSStyleDeclaration is not attached to a CSSRule.") def getProperties(self, name=None, all=False): """ :param name: optional `name` of properties which are requested. Only properties with this **always normalized** `name` are returned. If `name` is ``None`` all properties are returned (at least one for each set name depending on parameter `all`). :param all: if ``False`` (DEFAULT) only the effective properties are returned. If name is given a list with only one property is returned. if ``True`` all properties including properties set multiple times with different values or priorities for different UAs are returned. The order of the properties is fully kept as in the original stylesheet. :returns: a list of :class:`~cssutils.css.Property` objects set in this declaration. """ if name and not all: # single prop but list p = self.getProperty(name) if p: return [p] else: return [] elif not all: # effective Properties in name order return [self.getProperty(name) for name in self.__nnames()] else: # all properties or all with this name nname = self._normalize(name) properties = [] for item in self.seq: val = item.value if isinstance(val, Property) and ( (bool(nname) == False) or (val.name == nname)): properties.append(val) return properties def getProperty(self, name, normalize=True): """ :param name: of the CSS property, always lowercase (even if not normalized) :param normalize: if ``True`` (DEFAULT) name will be normalized (lowercase, no simple escapes) so "color", "COLOR" or "C\olor" will all be equivalent If ``False`` may return **NOT** the effective value but the effective for the unnormalized name. :returns: the effective :class:`~cssutils.css.Property` object. """ nname = self._normalize(name) found = None for item in reversed(self.seq): val = item.value if isinstance(val, Property): if (normalize and nname == val.name) or name == val.literalname: if val.priority: return val elif not found: found = val return found def getPropertyCSSValue(self, name, normalize=True): """ :param name: of the CSS property, always lowercase (even if not normalized) :param normalize: if ``True`` (DEFAULT) name will be normalized (lowercase, no simple escapes) so "color", "COLOR" or "C\olor" will all be equivalent If ``False`` may return **NOT** the effective value but the effective for the unnormalized name. :returns: :class:`~cssutils.css.CSSValue`, the value of the effective property if it has been explicitly set for this declaration block. (DOM) Used to retrieve the object representation of the value of a CSS property if it has been explicitly set within this declaration block. Returns None if the property has not been set. (This method returns None if the property is a shorthand property. Shorthand property values can only be accessed and modified as strings, using the getPropertyValue and setProperty methods.) **cssutils currently always returns a CSSValue if the property is set.** for more on shorthand properties see http://www.dustindiaz.com/css-shorthand/ """ nname = self._normalize(name) if nname in self._SHORTHANDPROPERTIES: self._log.info(u'CSSValue for shorthand property "%s" should be ' u'None, this may be implemented later.' % nname, neverraise=True) p = self.getProperty(name, normalize) if p: return p.cssValue else: return None def getPropertyValue(self, name, normalize=True): """ :param name: of the CSS property, always lowercase (even if not normalized) :param normalize: if ``True`` (DEFAULT) name will be normalized (lowercase, no simple escapes) so "color", "COLOR" or "C\olor" will all be equivalent If ``False`` may return **NOT** the effective value but the effective for the unnormalized name. :returns: the value of the effective property if it has been explicitly set for this declaration block. Returns the empty string if the property has not been set. """ p = self.getProperty(name, normalize) if p: return p.value else: return u'' def getPropertyPriority(self, name, normalize=True): """ :param name: of the CSS property, always lowercase (even if not normalized) :param normalize: if ``True`` (DEFAULT) name will be normalized (lowercase, no simple escapes) so "color", "COLOR" or "C\olor" will all be equivalent If ``False`` may return **NOT** the effective value but the effective for the unnormalized name. :returns: the priority of the effective CSS property (e.g. the "important" qualifier) if the property has been explicitly set in this declaration block. The empty string if none exists. """ p = self.getProperty(name, normalize) if p: return p.priority else: return u'' def removeProperty(self, name, normalize=True): """ (DOM) Used to remove a CSS property if it has been explicitly set within this declaration block. :param name: of the CSS property :param normalize: if ``True`` (DEFAULT) name will be normalized (lowercase, no simple escapes) so "color", "COLOR" or "C\olor" will all be equivalent. The effective Property value is returned and *all* Properties with ``Property.name == name`` are removed. If ``False`` may return **NOT** the effective value but the effective for the unnormalized `name` only. Also only the Properties with the literal name `name` are removed. :returns: the value of the property if it has been explicitly set for this declaration block. Returns the empty string if the property has not been set or the property name does not correspond to a known CSS property :exceptions: - :exc:`~xml.dom.NoModificationAllowedErr`: Raised if this declaration is readonly or the property is readonly. """ self._checkReadonly() r = self.getPropertyValue(name, normalize=normalize) newseq = self._tempSeq() if normalize: # remove all properties with name == nname nname = self._normalize(name) for item in self.seq: if not (isinstance(item.value, Property) and item.value.name == nname): newseq.appendItem(item) else: # remove all properties with literalname == name for item in self.seq: if not (isinstance(item.value, Property) and item.value.literalname == name): newseq.appendItem(item) self._setSeq(newseq) return r def setProperty(self, name, value=None, priority=u'', normalize=True, replace=True): """(DOM) Set a property value and priority within this declaration block. :param name: of the CSS property to set (in W3C DOM the parameter is called "propertyName"), always lowercase (even if not normalized) If a property with this `name` is present it will be reset. cssutils also allowed `name` to be a :class:`~cssutils.css.Property` object, all other parameter are ignored in this case :param value: the new value of the property, ignored if `name` is a Property. :param priority: the optional priority of the property (e.g. "important"), ignored if `name` is a Property. :param normalize: if True (DEFAULT) `name` will be normalized (lowercase, no simple escapes) so "color", "COLOR" or "C\olor" will all be equivalent :param replace: if True (DEFAULT) the given property will replace a present property. If False a new property will be added always. The difference to `normalize` is that two or more properties with the same name may be set, useful for e.g. stuff like:: background: red; background: rgba(255, 0, 0, 0.5); which defines the same property but only capable UAs use the last property value, older ones use the first value. :exceptions: - :exc:`~xml.dom.SyntaxErr`: Raised if the specified value has a syntax error and is unparsable. - :exc:`~xml.dom.NoModificationAllowedErr`: Raised if this declaration is readonly or the property is readonly. """ self._checkReadonly() if isinstance(name, Property): newp = name name = newp.literalname elif not value: # empty string or None effectively removed property return self.removeProperty(name) else: newp = Property(name, value, priority) if newp.wellformed: if replace: # check if update nname = self._normalize(name) properties = self.getProperties(name, all=(not normalize)) for property in reversed(properties): if normalize and property.name == nname: property.cssValue = newp.cssValue.cssText property.priority = newp.priority return elif property.literalname == name: property.cssValue = newp.cssValue.cssText property.priority = newp.priority return # not yet set or forced omit replace newp.parent = self self.seq._readonly = False self.seq.append(newp, 'Property') self.seq._readonly = True else: self._log.warn(u'Invalid Property: %s: %s %s' % (name, value, priority)) def item(self, index): """(DOM) Retrieve the properties that have been explicitly set in this declaration block. The order of the properties retrieved using this method does not have to be the order in which they were set. This method can be used to iterate over all properties in this declaration block. :param index: of the property to retrieve, negative values behave like negative indexes on Python lists, so -1 is the last element :returns: the name of the property at this ordinal position. The empty string if no property exists at this position. **ATTENTION:** Only properties with different names are counted. If two properties with the same name are present in this declaration only the effective one is included. :meth:`item` and :attr:`length` work on the same set here. """ names = list(self.__nnames()) try: return names[index] except IndexError: return u'' length = property(lambda self: len(list(self.__nnames())), doc=u"(DOM) The number of distinct properties that have " u"been explicitly in this declaration block. The " u"range of valid indices is 0 to length-1 inclusive. " u"These are properties with a different ``name`` " u"only. :meth:`item` and :attr:`length` work on the " u"same set here.") def _getValidating(self): try: # CSSParser.parseX() sets validating of stylesheet return self.parentRule.parentStyleSheet.validating except AttributeError: # CSSParser.parseStyle() sets validating of declaration if self._validating is not None: return self._validating # default return True def _setValidating(self, validating): self._validating = validating validating = property(_getValidating, _setValidating, doc=u"If ``True`` this declaration validates " u"contained properties. The parent StyleSheet " u"validation setting does *always* win though so " u"even if validating is True it may not validate " u"if the StyleSheet defines else!")