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

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 13

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 8

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 11

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 51

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.



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# File 'lib/css_parser/rule_set.rb', line 301

def create_background_shorthand! # :nodoc:
  new_value = ''
  ['background-color', 'background-image', 'background-repeat', 
   'background-position', 'background-attachment'].each do |property|
    if @declarations.has_key?(property)
      new_value += @declarations[property][:value] + ' '
      @declarations.delete(property)
    end
  end

  unless new_value.strip.empty?
    @declarations['background'] = {:value => new_value.gsub(/[\s]+/, ' ').strip}
  end
end

#create_dimensions_shorthand! ⇒ Object

Looks for long format CSS dimensional properties (i.e. margin and padding) and converts them into shorthand CSS properties.



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# File 'lib/css_parser/rule_set.rb', line 318

def create_dimensions_shorthand! # :nodoc:
  # geometric
  directions = ['top', 'right', 'bottom', 'left']
  ['margin', 'padding'].each do |property|
    values = {}      

    foldable = @declarations.select { |dim, val| dim == "#{property}-top" or dim == "#{property}-right" or dim == "#{property}-bottom" or dim == "#{property}-left" }
    # All four dimensions must be present
    if foldable.length == 4
      values = {}

      directions.each { |d| values[d.to_sym] = @declarations["#{property}-#{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 # done creating 'new_value'

      # Save the new value
      unless new_value.strip.empty?
        @declarations[property] = {:value => new_value.gsub(/[\s]+/, ' ').strip}
      end

      # Delete the shorthand values
      directions.each { |d| @declarations.delete("#{property}-#{d}") }
    end
  end # done iterating through margin and padding
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 360

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_shorthand! ⇒ Object

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



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# File 'lib/css_parser/rule_set.rb', line 120

def create_shorthand!
  create_background_shorthand!
  create_dimensions_shorthand!
  create_font_shorthand!
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 98

def declarations_to_s(options = {})
 options = {:force_important => false}.merge(options)
 str = ''
 importance = options[:force_important] ? ' !important' : ''
 each_declaration { |prop, val| str += "#{prop}: #{val}#{importance}; " }
 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 86

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 76

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 251

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

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

  bg_props = {}


  if m = value.match(Regexp.union(CssParser::URI_RX, /none/i)).to_s
    bg_props['background-image'] = m.strip unless m.empty?
    value.gsub!(Regexp.union(CssParser::URI_RX, /none/i), '')
  end

  if m = value.match(/([\s]*^)?(scroll|fixed)([\s]*$)?/i).to_s
    bg_props['background-attachment'] = m.strip unless m.empty?
  end

  if m = value.match(/([\s]*^)?(repeat(\-x|\-y)*|no\-repeat)([\s]*$)?/i).to_s
    bg_props['background-repeat'] = m.strip unless m.empty?
  end

  if m = value.match(CssParser::RE_COLOUR).to_s
    bg_props['background-color'] = m.strip unless m.empty?
  end

  value.scan(CssParser::RE_BACKGROUND_POSITION).each do |m|
    if bg_props.has_key?('background-position')
      bg_props['background-position'] += ' ' + m[0].to_s.strip unless m.empty?
    else
      bg_props['background-position'] =  m[0].to_s.strip unless m.empty?
    end
  end


  if value =~ /([\s]*^)?inherit([\s]*$)?/i
    ['background-color', 'background-image', 'background-attachment', 'background-repeat', 'background-position'].each do |prop|
        bg_props["#{prop}"] = 'inherit' unless bg_props.has_key?(prop) and not bg_props[prop].empty?
    end
  end

  bg_props.each { |bg_prop, bg_val| @declarations[bg_prop] = {:value => bg_val, :is_important => is_important, :order => order} }

  @declarations.delete('background')
end

#expand_dimensions_shorthand! ⇒ Object

Split shorthand dimensional declarations (e.g. margin: 0px auto;) into their constituent parts.



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

def expand_dimensions_shorthand! # :nodoc:
  ['margin', 'padding'].each do |property|

    next unless @declarations.has_key?(property)
    
    value = @declarations[property][:value]
    is_important = @declarations[property][:is_important]
    order = @declarations[property][:order]
    t, r, b, l = nil

    matches = value.scan(CssParser::BOX_MODEL_UNITS_RX)

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

    values = { :is_important => is_important, :order => order }
    @declarations["#{property}-top"]    = values.merge(:value => t.to_s)
    @declarations["#{property}-right"]  = values.merge(:value => r.to_s)
    @declarations["#{property}-bottom"] = values.merge(:value => b.to_s)
    @declarations["#{property}-left"]   = values.merge(:value => l.to_s)
    @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 193

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_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 113

def expand_shorthand!
  expand_dimensions_shorthand!
  expand_font_shorthand!
  expand_background_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 24

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

#to_s ⇒ Object

Return the CSS rule set as a string.



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# File 'lib/css_parser/rule_set.rb', line 107

def to_s
  decs = declarations_to_s
  "#{@selectors} { #{decs} }"
end