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://github.com/alexdunae/css_parser)"
STRIP_CSS_COMMENTS_RX = 
/\/\*.*?\*\//m
STRIP_HTML_COMMENTS_RX = 
/\<\!\-\-|\-\-\>/m
RE_AT_IMPORT_RULE =

Initial parsing

/\@import\s*(?:url\s*)?(?:\()?(?:\s*)["']?([^'"\s\)]*)["']?\)?([\w\s\,^\]\(\))]*)\)?[;\n]?/

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 35

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 33

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 27

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.

Use the :media_types option to set the media type(s) for this block. Takes an array of symbols.

Use the :only_media_types option to selectively follow @import rules. Takes an array of symbols.

Example

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

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



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# File 'lib/css_parser/parser.rb', line 97

def add_block!(block, options = {})
  options = {:base_uri => nil, :base_dir => nil, :charset => nil, :media_types => :all, :only_media_types => :all}.merge(options)
  options[:media_types] = [options[:media_types]].flatten.collect { |mt| CssParser.sanitize_media_query(mt)}
  options[:only_media_types] = [options[:only_media_types]].flatten.collect { |mt| CssParser.sanitize_media_query(mt)}

  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[-1]
      media_string.split(/[,]/).each do |t|
        media_types << CssParser.sanitize_media_query(t) unless t.empty?
      end
    else
      media_types = [:all]
    end
    
    next unless options[:only_media_types].include?(:all) or media_types.length < 1 or (media_types & options[:only_media_types]).length > 0

    import_path = import_rule[0].to_s.gsub(/['"]*/, '').strip
    
    if options[:base_uri]
      import_uri = Addressable::URI.parse(options[:base_uri].to_s) + Addressable::URI.parse(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 140

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 148

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

  media_types = [media_types].flatten.collect { |mt| CssParser.sanitize_media_query(mt)}

  @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 207

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 159

def each_rule_set(media_types = :all) # :yields: rule_set
  media_types = [:all] if media_types.nil?
  media_types = [media_types].flatten.collect { |mt| CssParser.sanitize_media_query(mt)}

  @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 174

def each_selector(media_types = :all, options = {}) # :yields: selectors, declarations, specificity
  each_rule_set(media_types) do |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 67

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 348

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)
  return unless circular_reference_check(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, options = {}, deprecated = nil) ⇒ Object

Load a remote CSS file.

You can also pass in file://test.css

See add_block! for options.

Deprecated: originally accepted three params: ‘uri`, `base_uri` and `media_types`



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# File 'lib/css_parser/parser.rb', line 321

def load_uri!(uri, options = {}, deprecated = nil)
  uri = Addressable::URI.parse(uri) unless uri.respond_to? :scheme
  #base_uri = nil, media_types = :all, options = {}

  opts = {:base_uri => nil, :media_types => :all}

  if options.is_a? Hash
    opts.merge!(options)
  else
    opts[:base_uri] = options if options.is_a? String
    opts[:media_types] = deprecated if deprecated
  end
        
  if uri.scheme == 'file' or uri.scheme.nil?
    uri.path = File.expand_path(uri.path)
    uri.scheme = 'file'
  end

  opts[:base_uri] = uri if opts[:base_uri].nil?

  src, charset = read_remote_file(uri)
  if src
    add_block!(src, opts)
  end
end

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

:nodoc:



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# File 'lib/css_parser/parser.rb', line 213

def parse_block_into_rule_sets!(block, options = {}) # :nodoc:
  current_media_queries = [:all]
  if options[:media_types]
    current_media_queries = options[:media_types].flatten.collect { |mt| CssParser.sanitize_media_query(mt)}
  end

  in_declarations = 0
  block_depth = 0

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

  current_selectors = ''
  current_media_query = ''
  current_declarations = ''

  block.scan(/([\\]?[{}\s"]|(.[^\s"{}\\]*))/).each do |matches|
    token = matches[0]

    if token =~ /\A"/ # found un-escaped double quote
      in_string = !in_string
    end       

    if in_declarations > 0
      # too deep, malformed declaration block
      if in_declarations > 1
        in_declarations -= 1 if token =~ /\}/
        next
      end
      
      if token =~ /\{/
        in_declarations += 1
        next
      end
    
      current_declarations += token

      if token =~ /\}/ and not in_string
        current_declarations.gsub!(/\}[\s]*$/, '')
        
        in_declarations -= 1

        unless current_declarations.strip.empty?
          add_rule!(current_selectors, current_declarations, current_media_queries)
        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
        in_media_block = true
        current_media_queries << CssParser.sanitize_media_query(current_media_query)
        current_media_query = ''
      elsif token =~ /[,]/
        # new media query begins
        token.gsub!(/[,]/, ' ')
        current_media_query += token.strip + ' '
        current_media_queries << CssParser.sanitize_media_query(current_media_query)
        current_media_query = ''
      else
        current_media_query += token.strip + ' '
      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

        # reset the current media query scope
        if in_media_block
          current_media_queries = []
          in_media_block = false
        end
      else
        if token =~ /\{/ and not in_string
          current_selectors.gsub!(/^[\s]*/, '')
          current_selectors.gsub!(/[\s]*$/, '')
          in_declarations += 1
        else
          current_selectors += token
        end
      end
    end
  end

  # check for unclosed braces          
  if in_declarations > 0
    add_rule!(current_selectors, current_declarations, current_media_queries)
  end
end

#rules_by_media_query ⇒ Object

A hash of { :media_query => rule_sets }



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# File 'lib/css_parser/parser.rb', line 192

def rules_by_media_query
  rules_by_media = {}
  @rules.each do |block|
    block[:media_types].each do |mt|
      unless rules_by_media.has_key?(mt)
        rules_by_media[mt] = []
      end
      rules_by_media[mt] << block[:rules]
    end
  end
  
  rules_by_media
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 183

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