Module: CssParser

Defined in:
lib/css_parser.rb,
lib/css_parser/parser.rb,
lib/css_parser/regexps.rb,
lib/css_parser/version.rb,
lib/css_parser/rule_set.rb

Defined Under Namespace

Classes: CircularReferenceError, OffsetAwareRuleSet, Parser, RemoteFileError, RuleSet

Constant Summary collapse

RE_NL =

:stopdoc: Base types

Regexp.new('(\n|\r\n|\r|\f)')
RE_NON_ASCII =
^0-177 
Regexp.new('([\x00-\xFF])', Regexp::IGNORECASE, 'n')
RE_UNICODE = 
Regexp.new('(\\\\[0-9a-f]{1,6}(\r\n|[ \n\r\t\f])*)', Regexp::IGNORECASE | Regexp::EXTENDED | Regexp::MULTILINE, 'n')
RE_ESCAPE = 
Regexp.union(RE_UNICODE, '|(\\\\[^\n\r\f0-9a-f])')
RE_IDENT = 
Regexp.new("[\-]?([_a-z]|#{RE_NON_ASCII}|#{RE_ESCAPE})([_a-z0-9\-]|#{RE_NON_ASCII}|#{RE_ESCAPE})*", Regexp::IGNORECASE, 'n')
RE_STRING1 =

General strings

Regexp.new('(\"(.[^\n\r\f\\"]*|\\\\' + RE_NL.to_s + '|' + RE_ESCAPE.to_s + ')*\")')
RE_STRING2 = 
Regexp.new('(\'(.[^\n\r\f\\\']*|\\\\' + RE_NL.to_s + '|' + RE_ESCAPE.to_s + ')*\')')
RE_STRING = 
Regexp.union(RE_STRING1, RE_STRING2)
RE_INHERIT = 
regex_possible_values 'inherit'
RE_URI = 
Regexp.new('(url\([\s]*([\s]*' + RE_STRING.to_s + '[\s]*)[\s]*\))|(url\([\s]*([!#$%&*\-~]|' + RE_NON_ASCII.to_s + '|' + RE_ESCAPE.to_s + ')*[\s]*)\)', Regexp::IGNORECASE | Regexp::EXTENDED  | Regexp::MULTILINE, 'n')
URI_RX = 
/url\(("([^"]*)"|'([^']*)'|([^)]*))\)/im
RE_GRADIENT = 
/[-a-z]*gradient\([-a-z0-9 .,#%()]*\)/im
RE_AT_IMPORT_RULE =

Initial parsing

/\@import\s+(url\()?["']?(.[^'"\s]*)["']?\)?([\w\s\,^\])]*)\)?;?/
IMPORTANT_IN_PROPERTY_RX =

RE_AT_IMPORT_RULE = Regexp.new(‘@import*(’ + RE_STRING.to_s + ‘)([ws,]*)?’, Regexp::IGNORECASE) – should handle url() even though it is not allowed ++

/[\s]*!important\b[\s]*/i
RE_INSIDE_OUTSIDE = 
regex_possible_values 'inside', 'outside'
RE_SCROLL_FIXED = 
regex_possible_values 'scroll', 'fixed'
RE_REPEAT = 
regex_possible_values 'repeat(\-x|\-y)*|no\-repeat'
RE_LIST_STYLE_TYPE = 
regex_possible_values 'disc', 'circle', 'square', 'decimal-leading-zero', 'decimal', 'lower-roman',
'upper-roman', 'lower-greek', 'lower-alpha', 'lower-latin', 'upper-alpha',
'upper-latin', 'hebrew', 'armenian', 'georgian', 'cjk-ideographic', 'hiragana',
'hira-gana-iroha', 'katakana-iroha', 'katakana', 'none'
STRIP_CSS_COMMENTS_RX = 
/\/\*.*?\*\//m
STRIP_HTML_COMMENTS_RX = 
/\<\!\-\-|\-\-\>/m
BOX_MODEL_UNITS_RX =

Special units

/(auto|inherit|0|([\-]*([0-9]+|[0-9]*\.[0-9]+)(rem|vw|vh|vm|vmin|vmax|e[mx]+|px|[cm]+m|p[tc+]|in|\%)))([\s;]|\Z)/imx
RE_LENGTH_OR_PERCENTAGE = 
Regexp.new('([\-]*(([0-9]*\.[0-9]+)|[0-9]+)(e[mx]+|px|[cm]+m|p[tc+]|in|\%))', Regexp::IGNORECASE)
RE_BACKGROUND_POSITION = 
Regexp.new("((((#{RE_LENGTH_OR_PERCENTAGE})|left|center|right|top|bottom)[\s]*){1,2})", Regexp::IGNORECASE | Regexp::EXTENDED)
RE_BACKGROUND_SIZE = 
Regexp.new("\\s*/\\s*((((#{RE_LENGTH_OR_PERCENTAGE})|auto|cover|contain|initial|inherit)[\\s]*){1,2})", Regexp::IGNORECASE | Regexp::EXTENDED)
FONT_UNITS_RX = 
/(([x]+\-)*small|medium|large[r]*|auto|inherit|([0-9]+|[0-9]*\.[0-9]+)(e[mx]+|px|[cm]+m|p[tc+]|in|\%)*)/i
RE_BORDER_STYLE = 
/([\s]*^)?(none|hidden|dotted|dashed|solid|double|dot-dash|dot-dot-dash|wave|groove|ridge|inset|outset)([\s]*$)?/imx
RE_BORDER_UNITS = 
Regexp.union(BOX_MODEL_UNITS_RX, /(thin|medium|thick)/i)
NON_ID_ATTRIBUTES_AND_PSEUDO_CLASSES_RX_NC =

Patterns for specificity calculations

/
  (?:\.[\w]+)                     # classes
  |
  \[(?:\w+)                       # attributes
  |
  (?:\:(?:                          # pseudo classes
    link|visited|active
    |hover|focus
    |lang
    |target
    |enabled|disabled|checked|indeterminate
    |root
    |nth-child|nth-last-child|nth-of-type|nth-last-of-type
    |first-child|last-child|first-of-type|last-of-type
    |only-child|only-of-type
    |empty|contains
  ))
/ix
ELEMENTS_AND_PSEUDO_ELEMENTS_RX_NC = 
/
  (?:(?:^|[\s\+\>\~]+)[\w]+       # elements
  |
  \:{1,2}(?:                    # pseudo-elements
    after|before
    |first-letter|first-line
    |selection
  )
)/ix
NAMED_COLOURS =

Colours

%w[
  aliceblue
  antiquewhite
  aqua
  aquamarine
  azure
  beige
  bisque
  black
  blanchedalmond
  blue
  blueviolet
  brown
  burlywood
  cadetblue
  chartreuse
  chocolate
  coral
  cornflowerblue
  cornsilk
  crimson
  cyan
  darkblue
  darkcyan
  darkgoldenrod
  darkgray
  darkgreen
  darkgrey
  darkkhaki
  darkmagenta
  darkolivegreen
  darkorange
  darkorchid
  darkred
  darksalmon
  darkseagreen
  darkslateblue
  darkslategray
  darkslategrey
  darkturquoise
  darkviolet
  deeppink
  deepskyblue
  dimgray
  dimgrey
  dodgerblue
  firebrick
  floralwhite
  forestgreen
  fuchsia
  gainsboro
  ghostwhite
  gold
  goldenrod
  gray
  green
  greenyellow
  grey
  honeydew
  hotpink
  indianred
  indigo
  ivory
  khaki
  lavender
  lavenderblush
  lawngreen
  lemonchiffon
  lightblue
  lightcoral
  lightcyan
  lightgoldenrodyellow
  lightgray
  lightgreen
  lightgrey
  lightpink
  lightsalmon
  lightseagreen
  lightskyblue
  lightslategray
  lightslategrey
  lightsteelblue
  lightyellow
  lime
  limegreen
  linen
  magenta
  maroon
  mediumaquamarine
  mediumblue
  mediumorchid
  mediumpurple
  mediumseagreen
  mediumslateblue
  mediumspringgreen
  mediumturquoise
  mediumvioletred
  midnightblue
  mintcream
  mistyrose
  moccasin
  navajowhite
  navy
  oldlace
  olive
  olivedrab
  orange
  orangered
  orchid
  palegoldenrod
  palegreen
  paleturquoise
  palevioletred
  papayawhip
  peachpuff
  peru
  pink
  plum
  powderblue
  purple
  red
  rosybrown
  royalblue
  saddlebrown
  salmon
  sandybrown
  seagreen
  seashell
  sienna
  silver
  skyblue
  slateblue
  slategray
  slategrey
  snow
  springgreen
  steelblue
  tan
  teal
  thistle
  tomato
  turquoise
  violet
  wheat
  white
  whitesmoke
  yellow
  yellowgreen

  transparent
  inherit
  currentColor
]
RE_COLOUR_NUMERIC = 
/\b(hsl|rgb)\s*\(-?\s*-?\d+(\.\d+)?%?\s*%?,-?\s*-?\d+(\.\d+)?%?\s*%?,-?\s*-?\d+(\.\d+)?%?\s*%?\)/i
RE_COLOUR_NUMERIC_ALPHA = 
/\b(hsla|rgba)\s*\(-?\s*-?\d+(\.\d+)?%?\s*%?,-?\s*-?\d+(\.\d+)?%?\s*%?,-?\s*-?\d+(\.\d+)?%?\s*%?,-?\s*-?\d+(\.\d+)?%?\s*%?\)/i
RE_COLOUR_HEX = 
/\s*#([0-9a-fA-F]{6}|[0-9a-fA-F]{3})\b/
RE_COLOUR_NAMED = 
/\s*\b(#{NAMED_COLOURS.join('|')})\b/i
RE_COLOUR = 
Regexp.union(RE_COLOUR_NUMERIC, RE_COLOUR_NUMERIC_ALPHA, RE_COLOUR_HEX, RE_COLOUR_NAMED)
VERSION = 
"1.7.0".freeze

Class Method Summary collapse

Class Method Details

.calculate_specificity(selector) ⇒ Object

Calculates the specificity of a CSS selector per www.w3.org/TR/CSS21/cascade.html#specificity

Returns an integer.

Example

CssParser.calculate_specificity('#content div p:first-line a:link')
=> 114

– Thanks to Rafael Salazar and Nick Fitzsimons on the css-discuss list for their help. ++



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# File 'lib/css_parser.rb', line 123

def self.calculate_specificity(selector)
  a = 0
  b = selector.scan(/\#/).length
  c = selector.scan(NON_ID_ATTRIBUTES_AND_PSEUDO_CLASSES_RX_NC).length
  d = selector.scan(ELEMENTS_AND_PSEUDO_ELEMENTS_RX_NC).length

  "#{a}#{b}#{c}#{d}".to_i
rescue
  return 0
end

.convert_uris(css, base_uri) ⇒ Object

Make url() links absolute.

Takes a block of CSS and returns it with all relative URIs converted to absolute URIs.

“For CSS style sheets, the base URI is that of the style sheet, not that of the source document.” per www.w3.org/TR/CSS21/syndata.html#uri

Returns a string.

Example

CssParser.convert_uris("body { background: url('../style/yellow.png?abc=123') };",
             "http://example.org/style/basic.css").inspect
=> "body { background: url('http://example.org/style/yellow.png?abc=123') };"



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# File 'lib/css_parser.rb', line 147

def self.convert_uris(css, base_uri)
  base_uri = Addressable::URI.parse(base_uri) unless base_uri.kind_of?(Addressable::URI)

  css.gsub(URI_RX) do
    uri = $1.to_s
    uri.gsub!(/["']+/, '')
    # Don't process URLs that are already absolute
    unless uri =~ /^[a-z]+\:\/\//i
      begin
        uri = base_uri + uri
      rescue; end
    end
    "url('#{uri.to_s}')"
  end
end

.merge(*rule_sets) ⇒ Object

Merge multiple CSS RuleSets by cascading according to the CSS 2.1 cascading rules (www.w3.org/TR/REC-CSS2/cascade.html#cascading-order).

Takes one or more RuleSet objects.

Returns a RuleSet.

Cascading

If a RuleSet object has its specificity defined, that specificity is used in the cascade calculations.

If no specificity is explicitly set and the RuleSet has one selector, the specificity is calculated using that selector.

If no selectors the specificity is treated as 0.

If multiple selectors are present then the greatest specificity is used.

Example #1

rs1 = RuleSet.new(nil, 'color: black;')
rs2 = RuleSet.new(nil, 'margin: 0px;')

merged = CssParser.merge(rs1, rs2)

puts merged
=> "{ margin: 0px; color: black; }"

Example #2

rs1 = RuleSet.new(nil, 'background-color: black;')
rs2 = RuleSet.new(nil, 'background-image: none;')

merged = CssParser.merge(rs1, rs2)

puts merged
=> "{ background: none black; }"

– TODO: declaration_hashes should be able to contain a RuleSet

this should be a Class method



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# File 'lib/css_parser.rb', line 55

def self.merge(*rule_sets)
  @folded_declaration_cache = {}

  # in case called like CssParser.merge([rule_set, rule_set])
  rule_sets.flatten! if rule_sets[0].kind_of?(Array)

  unless rule_sets.all? {|rs| rs.kind_of?(CssParser::RuleSet)}
    raise ArgumentError, "all parameters must be CssParser::RuleSets."
  end

  return rule_sets[0] if rule_sets.length == 1

  # Internal storage of CSS properties that we will keep
  properties = {}

  rule_sets.each do |rule_set|
    rule_set.expand_shorthand!

    specificity = rule_set.specificity
    unless specificity
      if rule_set.selectors.length == 0
        specificity = 0
      else
        specificity = rule_set.selectors.map { |s| calculate_specificity(s) }.compact.max || 0
      end
    end

    rule_set.each_declaration do |property, value, is_important|
      # Add the property to the list to be folded per http://www.w3.org/TR/CSS21/cascade.html#cascading-order
      if not properties.has_key?(property)
        properties[property] = {:value => value, :specificity => specificity, :is_important => is_important}
      elsif is_important
        if not properties[property][:is_important] or properties[property][:specificity] <= specificity
          properties[property] = {:value => value, :specificity => specificity, :is_important => is_important}
        end
      elsif properties[property][:specificity] < specificity or properties[property][:specificity] == specificity
        unless properties[property][:is_important]
          properties[property] = {:value => value, :specificity => specificity, :is_important => is_important}
        end
      end
   end
  end

  merged = RuleSet.new(nil, nil)

  properties.each do |property, details|
    if details[:is_important]
      merged[property.strip] = details[:value].strip.gsub(/\;\Z/, '') + '!important'
    else
      merged[property.strip] = details[:value].strip
    end
  end

  merged.create_shorthand!
  merged
end

.regex_possible_values(*values) ⇒ Object 



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# File 'lib/css_parser/regexps.rb', line 2

def self.regex_possible_values *values
  Regexp.new("([\s]*^)?(#{values.join('|')})([\s]*$)?", 'i')
end

.sanitize_media_query(raw) ⇒ Object 



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# File 'lib/css_parser.rb', line 163

def self.sanitize_media_query(raw)
  mq = raw.to_s.gsub(/[\s]+/, ' ')
  mq.strip!
  mq = 'all' if mq.empty?
  mq.to_sym
end