Class: CssParser::RuleSet

Inherits:
Object
  • Object
show all
Defined in:
lib/css_parser/rule_set.rb

Direct Known Subclasses

OffsetAwareRuleSet

Constant Summary collapse

RE_ELEMENTS_AND_PSEUDO_ELEMENTS =

Patterns for specificity calculations

/((^|[\s\+\>]+)[\w]+|\:(first\-line|first\-letter|before|after))/i
RE_NON_ID_ATTRIBUTES_AND_PSEUDO_CLASSES = 
/(\.[\w]+)|(\[[\w]+)|(\:(link|first\-child|lang))/i
BACKGROUND_PROPERTIES = 
['background-color', 'background-image', 'background-repeat', 'background-position', 'background-size', 'background-attachment']
LIST_STYLE_PROPERTIES = 
['list-style-type', 'list-style-position', 'list-style-image']
FONT_STYLE_PROPERTIES = 
['font-style', 'font-variant', 'font-weight', 'font-size', 'line-height', 'font-family']
BORDER_STYLE_PROPERTIES = 
['border-width', 'border-style', 'border-color']
BORDER_PROPERTIES = 
['border', 'border-left', 'border-right', 'border-top', 'border-bottom']
NUMBER_OF_DIMENSIONS = 
4
DIMENSIONS = 
[
['margin', %w(margin-top margin-right margin-bottom margin-left)],
['padding', %w(padding-top padding-right padding-bottom padding-left)],
['border-color', %w(border-top-color border-right-color border-bottom-color border-left-color)],
['border-style', %w(border-top-style border-right-style border-bottom-style border-left-style)],
['border-width', %w(border-top-width border-right-width border-bottom-width border-left-width)

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(selectors, block, specificity = nil) ⇒ RuleSet

Returns a new instance of RuleSet.



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# File 'lib/css_parser/rule_set.rb', line 30

def initialize(selectors, block, specificity = nil)
  @selectors = []
  @specificity = specificity
  @declarations = {}
  @order = 0
  parse_selectors!(selectors) if selectors
  parse_declarations!(block)
end

Instance Attribute Details

#selectors ⇒ Object (readonly)

Array of selector strings.



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# File 'lib/css_parser/rule_set.rb', line 25

def selectors
  @selectors
end

#specificity ⇒ Object

Integer with the specificity to use for this RuleSet.



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# File 'lib/css_parser/rule_set.rb', line 28

def specificity
  @specificity
end

Instance Method Details

#add_declaration!(property, value) ⇒ Object Also known as: []=

Add a CSS declaration to the current RuleSet.

rule_set.add_declaration!('color', 'blue')

puts rule_set['color']
=> 'blue;'

rule_set.add_declaration!('margin', '0px auto !important')

puts rule_set['margin']
=> '0px auto !important;'

If the property already exists its value will be over-written.



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# File 'lib/css_parser/rule_set.rb', line 67

def add_declaration!(property, value)
  if value.nil? or value.empty?
    @declarations.delete(property)
    return
  end

  value.gsub!(/;\Z/, '')
  is_important = !value.gsub!(CssParser::IMPORTANT_IN_PROPERTY_RX, '').nil?
  property = property.downcase
  property.strip!
  #puts "SAVING #{property}  #{value} #{is_important.inspect}"
  @declarations[property] = {
    :value => value, :is_important => is_important, :order => @order += 1
  }
end

#create_background_shorthand! ⇒ Object

Looks for long format CSS background properties (e.g. background-color) and converts them into a shorthand CSS background property.

Leaves properties declared !important alone.



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# File 'lib/css_parser/rule_set.rb', line 347

def create_background_shorthand! # :nodoc:
  # When we have a background-size property we must separate it and distinguish it from
  # background-position by preceding it with a backslash. In this case we also need to
  # have a background-position property, so we set it if it's missing.
  # http://www.w3schools.com/cssref/css3_pr_background.asp
  if @declarations.has_key?('background-size') and not @declarations['background-size'][:is_important]
    unless @declarations.has_key?('background-position')
      @declarations['background-position'] = {:value => '0% 0%'}
    end

    @declarations['background-size'][:value] = "/ #{@declarations['background-size'][:value]}"
  end

  create_shorthand_properties! BACKGROUND_PROPERTIES, 'background'
end

#create_border_shorthand! ⇒ Object

Combine border-color, border-style and border-width into border Should be run after create_dimensions_shorthand!

TODO: this is extremely similar to create_background_shorthand! and should be combined



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# File 'lib/css_parser/rule_set.rb', line 367

def create_border_shorthand! # :nodoc:
  values = []

  BORDER_STYLE_PROPERTIES.each do |property|
    if @declarations.has_key?(property) and not @declarations[property][:is_important]
      # can't merge if any value contains a space (i.e. has multiple values)
      # we temporarily remove any spaces after commas for the check (inside rgba, etc...)
      return if @declarations[property][:value].gsub(/\,[\s]/, ',').strip =~ /[\s]/
      values << @declarations[property][:value]
    end
  end

  BORDER_STYLE_PROPERTIES.each { |prop| @declarations.delete(prop)}

  unless values.empty?
    @declarations['border'] = {:value => values.join(' ')}
  end
end

#create_dimensions_shorthand! ⇒ Object

Looks for long format CSS dimensional properties (margin, padding, border-color, border-style and border-width) and converts them into shorthand CSS properties.



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# File 'lib/css_parser/rule_set.rb', line 388

def create_dimensions_shorthand! # :nodoc:
  return if @declarations.size < NUMBER_OF_DIMENSIONS

  DIMENSIONS.each do |property, dimensions|
    (top, right, bottom, left) = dimensions
    # All four dimensions must be present
    if dimensions.count { |d| @declarations[d] } == NUMBER_OF_DIMENSIONS
      values = {}

      [
        [:top, top],
        [:right, right],
        [:bottom, bottom],
        [:left, left],
      ].each { |d, key| values[d] = @declarations[key][:value].downcase.strip }

      if values[:left] == values[:right]
        if values[:top] == values[:bottom]
          if values[:top] == values[:left] # All four sides are equal
            new_value = values[:top]
          else # Top and bottom are equal, left and right are equal
            new_value = values[:top] + ' ' + values[:left]
          end
        else # Only left and right are equal
          new_value = values[:top] + ' ' + values[:left] + ' ' + values[:bottom]
        end
      else # No sides are equal
        new_value = values[:top] + ' ' + values[:right] + ' ' + values[:bottom] + ' ' + values[:left]
      end

      new_value.strip!
      @declarations[property] = {:value => new_value.strip} unless new_value.empty?

      # Delete the longhand values
      [top, right, bottom, left].each { |d| @declarations.delete(d) }
    end
  end
end

#create_font_shorthand! ⇒ Object

Looks for long format CSS font properties (e.g. font-weight) and tries to convert them into a shorthand CSS font property. All font properties must be present in order to create a shorthand declaration.



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# File 'lib/css_parser/rule_set.rb', line 431

def create_font_shorthand! # :nodoc:
  FONT_STYLE_PROPERTIES.each do |prop|
    return unless @declarations.has_key?(prop)
  end

  new_value = String.new
  ['font-style', 'font-variant', 'font-weight'].each do |property|
    unless @declarations[property][:value] == 'normal'
      new_value << @declarations[property][:value] << ' '
    end
  end

  new_value << @declarations['font-size'][:value]

  unless @declarations['line-height'][:value] == 'normal'
    new_value << '/' << @declarations['line-height'][:value]
  end

  new_value << ' ' << @declarations['font-family'][:value]

  @declarations['font'] = {:value => new_value.gsub(/[\s]+/, ' ').strip}

  FONT_STYLE_PROPERTIES.each { |prop| @declarations.delete(prop) }
end

#create_list_style_shorthand! ⇒ Object

Looks for long format CSS list-style properties (e.g. list-style-type) and converts them into a shorthand CSS list-style property.

Leaves properties declared !important alone.



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# File 'lib/css_parser/rule_set.rb', line 460

def create_list_style_shorthand! # :nodoc:
  create_shorthand_properties! LIST_STYLE_PROPERTIES, 'list-style'
end

#create_shorthand! ⇒ Object

Create shorthand declarations (e.g. margin or font) whenever possible.



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# File 'lib/css_parser/rule_set.rb', line 314

def create_shorthand!
  create_background_shorthand!
  create_dimensions_shorthand!
  # border must be shortened after dimensions
  create_border_shorthand!
  create_font_shorthand!
  create_list_style_shorthand!
end

#create_shorthand_properties!(properties, shorthand_property) ⇒ Object

Combine several properties into a shorthand one



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# File 'lib/css_parser/rule_set.rb', line 324

def create_shorthand_properties! properties, shorthand_property # :nodoc:
  values = []
  properties_to_delete = []
  properties.each do |property|
    if @declarations.has_key?(property) and not @declarations[property][:is_important]
      values << @declarations[property][:value]
      properties_to_delete << property
    end
  end

  if values.length > 1
    properties_to_delete.each do |property|
      @declarations.delete(property)
    end

    @declarations[shorthand_property] = {:value => values.join(' ')}
  end
end

#declarations_to_s(options = {}) ⇒ Object

Return all declarations as a string. – TODO: Clean-up regexp doesn’t seem to work ++



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# File 'lib/css_parser/rule_set.rb', line 122

def declarations_to_s(options = {})
  str = String.new
  each_declaration do |prop, val, is_important|
    importance = (options[:force_important] || is_important) ? ' !important' : ''
    str << "#{prop}: #{val}#{importance}; "
  end
  str.gsub!(/^[\s^(\{)]+|[\n\r\f\t]*|[\s]+$/mx, '')
  str.strip!
  str
end

#each_declaration ⇒ Object

Iterate through declarations.



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# File 'lib/css_parser/rule_set.rb', line 110

def each_declaration # :yields: property, value, is_important
  decs = @declarations.sort { |a,b| a[1][:order].nil? || b[1][:order].nil? ? 0 : a[1][:order] <=> b[1][:order] }
  decs.each do |property, data|
    value = data[:value]
    yield property.downcase.strip, value.strip, data[:is_important]
  end
end

#each_selector(options = {}) ⇒ Object

Iterate through selectors.

Options

  • force_important – boolean

Example

ruleset.each_selector do |sel, dec, spec|
  ...
end



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# File 'lib/css_parser/rule_set.rb', line 100

def each_selector(options = {}) # :yields: selector, declarations, specificity
  declarations = declarations_to_s(options)
  if @specificity
    @selectors.each { |sel| yield sel.strip, declarations, @specificity }
  else
    @selectors.each { |sel| yield sel.strip, declarations, CssParser.calculate_specificity(sel) }
  end
end

#expand_background_shorthand! ⇒ Object

Convert shorthand background declarations (e.g. background: url("chess.png") gray 50% repeat fixed;) into their constituent parts.

See www.w3.org/TR/CSS21/colors.html#propdef-background



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# File 'lib/css_parser/rule_set.rb', line 153

def expand_background_shorthand! # :nodoc:
  return unless @declarations.has_key?('background')

  value = @declarations['background'][:value]

  if value =~ CssParser::RE_INHERIT
    BACKGROUND_PROPERTIES.each do |prop|
      split_declaration('background', prop, 'inherit')
    end
  end

  split_declaration('background', 'background-image', value.slice!(Regexp.union(CssParser::URI_RX, CssParser::RE_GRADIENT, /none/i)))
  split_declaration('background', 'background-attachment', value.slice!(CssParser::RE_SCROLL_FIXED))
  split_declaration('background', 'background-repeat', value.slice!(CssParser::RE_REPEAT))
  split_declaration('background', 'background-color', value.slice!(CssParser::RE_COLOUR))
  split_declaration('background', 'background-size', extract_background_size_from(value))
  split_declaration('background', 'background-position', value.slice(CssParser::RE_BACKGROUND_POSITION))

  @declarations.delete('background')
end

#expand_border_shorthand! ⇒ Object

Split shorthand border declarations (e.g. border: 1px red;) Additional splitting happens in expand_dimensions_shorthand!



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# File 'lib/css_parser/rule_set.rb', line 182

def expand_border_shorthand! # :nodoc:
  BORDER_PROPERTIES.each do |k|
    next unless @declarations.has_key?(k)

    value = @declarations[k][:value]

    split_declaration(k, "#{k}-width", value.slice!(CssParser::RE_BORDER_UNITS))
    split_declaration(k, "#{k}-color", value.slice!(CssParser::RE_COLOUR))
    split_declaration(k, "#{k}-style", value.slice!(CssParser::RE_BORDER_STYLE))

    @declarations.delete(k)
  end
end

#expand_dimensions_shorthand! ⇒ Object

Split shorthand dimensional declarations (e.g. margin: 0px auto;) into their constituent parts. Handles margin, padding, border-color, border-style and border-width.



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# File 'lib/css_parser/rule_set.rb', line 198

def expand_dimensions_shorthand! # :nodoc:
  DIMENSIONS.each do |property, (top, right, bottom, left)|
    next unless @declarations.has_key?(property)
    value = @declarations[property][:value]

    # RGB and HSL values in borders are the only units that can have spaces (within params).
    # We cheat a bit here by stripping spaces after commas in RGB and HSL values so that we
    # can split easily on spaces.
    #
    # TODO: rgba, hsl, hsla
    value.gsub!(RE_COLOUR) { |c| c.gsub(/(\s*\,\s*)/, ',') }

    matches = value.strip.split(/\s+/)

    case matches.length
    when 1
      values = matches.to_a * 4
    when 2
      values = matches.to_a * 2
    when 3
      values = matches.to_a
      values << matches[1] # left = right
    when 4
      values = matches.to_a
    end

    t, r, b, l = values

    split_declaration(property, top, t)
    split_declaration(property, right, r)
    split_declaration(property, bottom, b)
    split_declaration(property, left, l)

    @declarations.delete(property)
  end
end

#expand_font_shorthand! ⇒ Object

Convert shorthand font declarations (e.g. font: 300 italic 11px/14px verdana, helvetica, sans-serif;) into their constituent parts.



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# File 'lib/css_parser/rule_set.rb', line 237

def expand_font_shorthand! # :nodoc:
  return unless @declarations.has_key?('font')

  font_props = {}

  # reset properties to 'normal' per http://www.w3.org/TR/CSS21/fonts.html#font-shorthand
  ['font-style', 'font-variant', 'font-weight', 'font-size',
   'line-height'].each do |prop|
    font_props[prop] = 'normal'
   end

  value = @declarations['font'][:value]
  value.gsub!(/\/\s+/, '/') # handle spaces between font size and height shorthand (e.g. 14px/ 16px)
  is_important = @declarations['font'][:is_important]
  order = @declarations['font'][:order]

  in_fonts = false

  matches = value.scan(/("(.*[^"])"|'(.*[^'])'|(\w[^ ,]+))/)
  matches.each do |match|
    m = match[0].to_s.strip
    m.gsub!(/[;]$/, '')

    if in_fonts
      if font_props.has_key?('font-family')
        font_props['font-family'] += ', ' + m
      else
        font_props['font-family'] = m
      end
    elsif m =~ /normal|inherit/i
      ['font-style', 'font-weight', 'font-variant'].each do |font_prop|
        font_props[font_prop] = m unless font_props.has_key?(font_prop)
      end
    elsif m =~ /italic|oblique/i
      font_props['font-style'] = m
    elsif m =~ /small\-caps/i
      font_props['font-variant'] = m
    elsif m =~ /[1-9]00$|bold|bolder|lighter/i
      font_props['font-weight'] = m
    elsif m =~ CssParser::FONT_UNITS_RX
      if m =~ /\//
        font_props['font-size'], font_props['line-height'] = m.split('/')
      else
        font_props['font-size'] = m
      end
      in_fonts = true
    end
  end

  font_props.each { |font_prop, font_val| @declarations[font_prop] = {:value => font_val, :is_important => is_important, :order => order} }

  @declarations.delete('font')
end

#expand_list_style_shorthand! ⇒ Object

Convert shorthand list-style declarations (e.g. list-style: lower-alpha outside;) into their constituent parts.

See www.w3.org/TR/CSS21/generate.html#lists



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# File 'lib/css_parser/rule_set.rb', line 295

def expand_list_style_shorthand! # :nodoc:
  return unless @declarations.has_key?('list-style')

  value = @declarations['list-style'][:value]

  if value =~ CssParser::RE_INHERIT
    LIST_STYLE_PROPERTIES.each do |prop|
      split_declaration('list-style', prop, 'inherit')
    end
  end

  split_declaration('list-style', 'list-style-type', value.slice!(CssParser::RE_LIST_STYLE_TYPE))
  split_declaration('list-style', 'list-style-position', value.slice!(CssParser::RE_INSIDE_OUTSIDE))
  split_declaration('list-style', 'list-style-image', value.slice!(Regexp.union(CssParser::URI_RX, /none/i)))

  @declarations.delete('list-style')
end

#expand_shorthand! ⇒ Object

Split shorthand declarations (e.g. margin or font) into their constituent parts.



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# File 'lib/css_parser/rule_set.rb', line 140

def expand_shorthand!
  # border must be expanded before dimensions
  expand_border_shorthand!
  expand_dimensions_shorthand!
  expand_font_shorthand!
  expand_background_shorthand!
  expand_list_style_shorthand!
end

#extract_background_size_from(value) ⇒ Object 



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# File 'lib/css_parser/rule_set.rb', line 174

def extract_background_size_from(value)
  size = value.slice!(CssParser::RE_BACKGROUND_SIZE)

  size.sub(/^\s*\/\s*/, '') if size
end

#get_value(property) ⇒ Object Also known as: []

Get the value of a property



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# File 'lib/css_parser/rule_set.rb', line 40

def get_value(property)
  return '' unless property and not property.empty?

  property = property.downcase.strip
  properties = @declarations.inject(String.new) do |val, (key, data)|
    #puts "COMPARING #{key} #{key.inspect} against #{property} #{property.inspect}"
    importance = data[:is_important] ? ' !important' : ''
    val << "#{data[:value]}#{importance}; " if key.downcase.strip == property
    val
  end
  return properties ? properties.strip : ''
end

#remove_declaration!(property) ⇒ Object

Remove CSS declaration from the current RuleSet.

rule_set.remove_declaration!('color')



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# File 'lib/css_parser/rule_set.rb', line 87

def remove_declaration!(property)
  @declarations.delete(property)
end

#to_s ⇒ Object

Return the CSS rule set as a string.



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# File 'lib/css_parser/rule_set.rb', line 134

def to_s
  decs = declarations_to_s
  "#{@selectors.join(',')} { #{decs} }"
end