Class: CssDryer::Processor::StateMachine

Inherits:

Object

• Object
• CssDryer::Processor::StateMachine

Defined in:

lib/css_dryer/processor.rb

Overview

:nodoc:

Instance Method Summary

• #act_on(input) ⇒ Object
• #initialize(indent = 2) ⇒ StateMachine constructor

  A new instance of StateMachine.

• #result ⇒ Object

Constructor Details

#initialize(indent = 2) ⇒ StateMachine

# File 'lib/css_dryer/processor.rb', line 215

def initialize(indent = 2)
  @state = 'flow'
  @depth = 0
  @output = []
  @indent = ' ' * indent
end

Instance Method Details

#act_on(input) ⇒ Object

# File 'lib/css_dryer/processor.rb', line 224

def act_on(input)
  # Implementation notes:
  # - the correct way to do this would be to use a lexer and parser
  if @state.eql? 'flow'
    case input
    when %r{/[*]}  # open comment
      @state = 'reading_comments'
      act_on input
    when /^[^,]*$/    # no commas
      @output << input
    when /,.*;\s*$/   # comma separated style values
      @output << input
    when /@media/     # @media block
      @output << input
    when /,/          # commas
      @state = 'reading_selectors'
      @selectors = []
      @styles = []
      act_on input
    end
    return

  elsif @state.eql? 'reading_comments'
    # Dodgy hack: remove commas from comments so that the
    # factor_out_comma_separated_selectors method doesn't
    # go into an infinite loop.
    @output << input.gsub(',', ' ')
    if input =~ %r{[*]/}   # close comment
      @state = 'flow'
    end
    return

  elsif @state.eql? 'reading_selectors'
    if input !~ /[{]/
      @selectors << extract_selectors(input)
    else
      @selectors << extract_selectors($`)
      @state = 'reading_styles'
      act_on input
    end
    return

  elsif @state.eql? 'reading_styles'
    case input
    when /\A[^{}]*\Z/           # no braces
      @styles << input
    when /\A[^,]*[{](.*)[}]/    # inline styles (no commas)
      @styles << (@depth == 0 ? $1 : input)
    when /[{](.*)[}]/           # inline styles (commas)
      @styles << $1
    when /[{][^}]*\Z/           # open multiline block
      @styles << input unless @depth == 0
      @depth += 1
    when /[^{]*[}]/             # close multiline block
      @depth -= 1
      @styles << input unless @depth == 0
    end
    if @depth == 0 && input =~ /[}]/
      @selectors.flatten.each { |selector|
        # Force each style declaration onto a new line.
        @output << "#{selector} {\n"
        @styles.each { |style| @output << "#{@indent}#{style.chomp.strip}\n" }
        @output << "}\n"
      }
      @state = 'flow'
    end
    return

  end
end

#result ⇒ Object

# File 'lib/css_dryer/processor.rb', line 221

def result
  @output.join
end