Class: CssParser::Parser

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

Overview

Parser class

All CSS is converted to UTF-8.

When calling Parser#new there are some configuaration options:

absolute_paths

Convert relative paths to absolute paths (href, src and url(''). Boolean, default is false.

import

Follow @import rules. Boolean, default is true.

io_exceptions

Throw an exception if a link can not be found. Boolean, default is true.

Constant Summary collapse

USER_AGENT = 
"Ruby CSS Parser/#{CssParser::VERSION} (http://code.dunae.ca/css_parser/)"
STRIP_CSS_COMMENTS_RX = 
/\/\*.*?\*\//m
STRIP_HTML_COMMENTS_RX = 
/\<\!\-\-|\-\-\>/m
RE_AT_IMPORT_RULE =

Initial parsing

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

Class Attribute Summary collapse

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(options = {}) ⇒ Parser

Returns a new instance of Parser.



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# File 'lib/css_parser/parser.rb', line 41

def initialize(options = {})
  @options = {:absolute_paths => false,
              :import => true,
              :io_exceptions => true}.merge(options)

  # array of RuleSets
  @rules = []

  
  @loaded_uris = []

  # unprocessed blocks of CSS
  @blocks = []
  reset!
end

Class Attribute Details

.folded_declaration_cache ⇒ Object (readonly)

Returns the value of attribute folded_declaration_cache.



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# File 'lib/css_parser/parser.rb', line 39

def folded_declaration_cache
  @folded_declaration_cache
end

Instance Attribute Details

#loaded_uris ⇒ Object (readonly)

Array of CSS files that have been loaded.



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# File 'lib/css_parser/parser.rb', line 31

def loaded_uris
  @loaded_uris
end

Instance Method Details

#add_block!(block, options = {}) ⇒ Object

Add a raw block of CSS.

In order to follow @import rules you must supply either a :base_dir or :base_uri option.

Example

css = <<-EOT
  body { font-size: 10pt }
  p { margin: 0px; }
  @media screen, print {
    body { line-height: 1.2 }
  }
EOT

parser = CssParser::Parser.new
parser.load_css!(css)

– TODO: add media_type ++



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# File 'lib/css_parser/parser.rb', line 102

def add_block!(block, options = {})
  options = {:base_uri => nil, :base_dir => nil, :charset => nil, :media_types => :all}.merge(options)
  
  block = cleanup_block(block)

  if options[:base_uri] and @options[:absolute_paths]
    block = CssParser.convert_uris(block, options[:base_uri])
  end

  # Load @imported CSS
  block.scan(RE_AT_IMPORT_RULE).each do |import_rule|        
    media_types = []
    if media_string = import_rule[import_rule.length-1]
      media_string.split(/\s|\,/).each do |t|
        media_types << t.to_sym unless t.empty?
      end
    end

    import_path = import_rule[1].to_s.gsub(/['"]*/, '').strip
    
    if options[:base_uri]
      import_uri = URI.parse(options[:base_uri].to_s).merge(import_path)
      load_uri!(import_uri, options[:base_uri], media_types)
    elsif options[:base_dir]
      load_file!(import_path, options[:base_dir], media_types)
    end     
  end

  # Remove @import declarations
  block.gsub!(RE_AT_IMPORT_RULE, '')


  
  parse_block_into_rule_sets!(block, options)
  
end

#add_rule!(selectors, declarations, media_types = :all) ⇒ Object

Add a CSS rule by setting the selectors, declarations and media_types.

media_types can be a symbol or an array of symbols.



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# File 'lib/css_parser/parser.rb', line 142

def add_rule!(selectors, declarations, media_types = :all)
  rule_set = RuleSet.new(selectors, declarations)
  add_rule_set!(rule_set, media_types)
end

#add_rule_set!(ruleset, media_types = :all) ⇒ Object

Add a CssParser RuleSet object.

media_types can be a symbol or an array of symbols.

Raises:

  • (ArgumentError) 


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# File 'lib/css_parser/parser.rb', line 150

def add_rule_set!(ruleset, media_types = :all)
  raise ArgumentError unless ruleset.kind_of?(CssParser::RuleSet)

  media_types = [media_types] if media_types.kind_of?(Symbol)

  @rules << {:media_types => media_types, :rules => ruleset}
end

#compact! ⇒ Object

Merge declarations with the same selector.



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# File 'lib/css_parser/parser.rb', line 195

def compact! # :nodoc:
  compacted = []

  compacted
end

#each_rule_set(media_types = :all) ⇒ Object

Iterate through RuleSet objects.

media_types can be a symbol or an array of symbols.



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# File 'lib/css_parser/parser.rb', line 161

def each_rule_set(media_types = :all) # :yields: rule_set
  media_types = [:all] if media_types.nil?
  media_types = [media_types] if media_types.kind_of?(Symbol)

  @rules.each do |block|
    if media_types.include?(:all) or block[:media_types].any? { |mt| media_types.include?(mt) }
      yield block[:rules]
    end
  end
end

#each_selector(media_types = :all, options = {}) ⇒ Object

Iterate through CSS selectors.

media_types can be a symbol or an array of symbols. See RuleSet#each_selector for options.



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# File 'lib/css_parser/parser.rb', line 176

def each_selector(media_types = :all, options = {}) # :yields: selectors, declarations, specificity
  each_rule_set(media_types) do |rule_set|
    #puts rule_set
    rule_set.each_selector(options) do |selectors, declarations, specificity|
      yield selectors, declarations, specificity
    end
  end
end

#find_by_selector(selector, media_types = :all) ⇒ Object Also known as: []

Get declarations by selector.

media_types are optional, and can be a symbol or an array of symbols. The default value is :all.

Examples

find_by_selector('#content')
=> 'font-size: 13px; line-height: 1.2;'

find_by_selector('#content', [:screen, :handheld])
=> 'font-size: 13px; line-height: 1.2;'

find_by_selector('#content', :print)
=> 'font-size: 11pt; line-height: 1.2;'

Returns an array of declarations.



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# File 'lib/css_parser/parser.rb', line 73

def find_by_selector(selector, media_types = :all)
  out = []
  each_selector(media_types) do |sel, dec, spec|
    out << dec if sel.strip == selector.strip
  end
  out
end

#load_file!(file_name, base_dir = nil, media_types = :all) ⇒ Object

Load a local CSS file.



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# File 'lib/css_parser/parser.rb', line 281

def load_file!(file_name, base_dir = nil, media_types = :all)
  file_name = File.expand_path(file_name, base_dir)
  return unless File.readable?(file_name)

  src = IO.read(file_name)
  base_dir = File.dirname(file_name)

  add_block!(src, {:media_types => media_types, :base_dir => base_dir})
end

#load_uri!(uri, base_uri = nil, media_types = :all) ⇒ Object

Load a remote CSS file.



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# File 'lib/css_parser/parser.rb', line 273

def load_uri!(uri, base_uri = nil, media_types = :all)
  base_uri = uri if base_uri.nil?
  src, charset = read_remote_file(uri)

  add_block!(src, {:media_types => media_types, :base_uri => base_uri})
end

#parse_block_into_rule_sets!(block, options = {}) ⇒ Object

:nodoc:



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# File 'lib/css_parser/parser.rb', line 201

def parse_block_into_rule_sets!(block, options = {}) # :nodoc:
  options = {:media_types => :all}.merge(options)
  media_types = options[:media_types]

  in_declarations = false

  block_depth = 0

  # @charset is ignored for now
  in_charset = false
  in_string = false
  in_at_media_rule = false

  current_selectors = ''
  current_declarations = ''

  block.scan(/([\\]?[{}\s"]|(.[^\s"{}\\]*))/).each do |matches|
  #block.scan(/((.[^{}"\n\r\f\s]*)[\s]|(.[^{}"\n\r\f]*)\{|(.[^{}"\n\r\f]*)\}|(.[^{}"\n\r\f]*)\"|(.*)[\s]+)/).each do |matches|
    token = matches[0]
    #puts "TOKEN: #{token}" unless token =~ /^[\s]*$/
    if token =~ /\A"/ # found un-escaped double quote
      in_string = !in_string
    end       

    if in_declarations
      current_declarations += token

      if token =~ /\}/ and not in_string
        current_declarations.gsub!(/\}[\s]*$/, '')
        
        in_declarations = false

        unless current_declarations.strip.empty?
          #puts "SAVING #{current_selectors} -> #{current_declarations}"
          add_rule!(current_selectors, current_declarations, media_types)
        end

        current_selectors = ''
        current_declarations = ''
      end
    elsif token =~ /@media/i
      # found '@media', reset current media_types
      in_at_media_rule = true
      media_types = []
    elsif in_at_media_rule
      if token =~ /\{/
        block_depth = block_depth + 1
        in_at_media_rule = false
      else
        token.gsub!(/[,\s]*/, '')
        media_types << token.strip.downcase.to_sym unless token.empty?
      end
    elsif in_charset or token =~ /@charset/i
      # iterate until we are out of the charset declaration
      in_charset = (token =~ /;/ ? false : true)
    else
      if token =~ /\}/ and not in_string
        block_depth = block_depth - 1
      else
        if token =~ /\{/ and not in_string
          current_selectors.gsub!(/^[\s]*/, '')
          current_selectors.gsub!(/[\s]*$/, '')
          in_declarations = true
        else
          current_selectors += token
        end
      end
    end
  end
end

#to_s(media_types = :all) ⇒ Object

Output all CSS rules as a single stylesheet.



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# File 'lib/css_parser/parser.rb', line 186

def to_s(media_types = :all)
  out = ''
  each_selector(media_types) do |selectors, declarations, specificity|
    out << "#{selectors} {\n#{declarations}\n}\n"
  end
  out
end