Class: CssParser::RuleSet

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

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-attachment']
LIST_STYLE_PROPERTIES = 
['list-style-type', 'list-style-position', 'list-style-image']

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 16

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 11

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 14

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 54

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.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 330

def create_background_shorthand! # :nodoc:
  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 338

def create_border_shorthand! # :nodoc:
  values = []
  
  ['border-width', 'border-style', 'border-color'].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

  @declarations.delete('border-width')
  @declarations.delete('border-style')
  @declarations.delete('border-color')

  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 361

def create_dimensions_shorthand! # :nodoc:
  directions = ['top', 'right', 'bottom', 'left']

  {'margin'       => 'margin-%s',
   'padding'      => 'padding-%s',
   'border-color' => 'border-%s-color', 
   'border-style' => 'border-%s-style', 
   'border-width' => 'border-%s-width'}.each do |property, expanded|

    foldable = @declarations.select do |dim, val| 
      dim == expanded % 'top' or dim == expanded % 'right' or dim == expanded % 'bottom' or dim == expanded % 'left'
    end
    # All four dimensions must be present
    if foldable.length == 4
      values = {}

      directions.each { |d| values[d.to_sym] = @declarations[expanded % d][: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
      directions.each { |d| @declarations.delete(expanded % 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 406

def create_font_shorthand! # :nodoc:
  ['font-style', 'font-variant', 'font-weight', 'font-size',
   'line-height', 'font-family'].each do |prop|
    return unless @declarations.has_key?(prop)
  end

  new_value = ''
  ['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', 'font-variant', 'font-weight', 'font-size',
   'line-height', 'font-family'].each do |prop|
   @declarations.delete(prop)
  end

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 440

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 302

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 312

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

  unless values.empty?
    @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 108

def declarations_to_s(options = {})
 options = {:force_important => false}.merge(options)
 str = ''
 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, '').strip
end

#each_declaration ⇒ Object

Iterate through declarations.



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# File 'lib/css_parser/rule_set.rb', line 96

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 86

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 138

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, /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-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 160

def expand_border_shorthand! # :nodoc:
  ['border', 'border-left', 'border-right', 'border-top', 'border-bottom'].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 176

def expand_dimensions_shorthand! # :nodoc:
  {'margin'       => 'margin-%s',
   'padding'      => 'padding-%s',
   'border-color' => 'border-%s-color', 
   'border-style' => 'border-%s-style', 
   'border-width' => 'border-%s-width'}.each do |property, expanded|

    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]+/, '') }

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

    t, r, b, l = nil

    case matches.length
      when 1
        t, r, b, l = matches[0], matches[0], matches[0], matches[0]
      when 2
        t, b = matches[0], matches[0]
        r, l = matches[1], matches[1]
      when 3
        t =  matches[0]
        r, l = matches[1], matches[1]
        b =  matches[2]
      when 4
        t =  matches[0]
        r = matches[1]
        b =  matches[2]
        l = matches[3]
    end

    split_declaration(property, expanded % 'top', t)
    split_declaration(property, expanded % 'right', r)
    split_declaration(property, expanded % 'bottom', b)
    split_declaration(property, expanded % '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 226

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]
  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 283

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 125

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

#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 27

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

  property = property.downcase.strip
  properties = @declarations.inject('') 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 73

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 119

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