Class: Sass::Tree::Visitors::ToCss

Inherits:
Base
  • Object
show all
Defined in:
lib/sass/tree/visitors/to_css.rb

Overview

A visitor for converting a Sass tree into CSS.

Constant Summary collapse

NEWLINE =

Avoid allocating lots of new strings for #output. This is important because #output is called all the time.

"\n"

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods inherited from Base

node_name, visit, #visit_children, #visit_if

Constructor Details

#initialize(build_source_mapping = false) ⇒ ToCss

Returns a new instance of ToCss

Parameters:

  • build_source_mapping (Boolean) (defaults to: false)

    Whether to build a Source::Map while creating the CSS output. The mapping will be available from #source_mapping after the visitor has completed.


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# File 'lib/sass/tree/visitors/to_css.rb', line 11

def initialize(build_source_mapping = false)
  @tabs = 0
  @line = 1
  @offset = 1
  @result = String.new("")
  @source_mapping = build_source_mapping ? Sass::Source::Map.new : nil
  @lstrip = nil
  @in_directive = false
end

Instance Attribute Details

#source_mapping (readonly)

The source mapping for the generated CSS file. This is only set if build_source_mapping is passed to the constructor and Engine#render has been run.


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# File 'lib/sass/tree/visitors/to_css.rb', line 6

def source_mapping
  @source_mapping
end

Instance Method Details

#erase!(chars) (protected)

Move the output cursor back chars characters.


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# File 'lib/sass/tree/visitors/to_css.rb', line 61

def erase!(chars)
  return if chars == 0
  str = @result.slice!(-chars..-1)
  newlines = str.count("\n")
  if newlines > 0
    @line -= newlines
    @offset = @result[@result.rindex("\n") || 0..-1].size
  else
    @offset -= chars
  end
end

#for_node(node, attr_prefix = nil) (protected)

Associate all output produced in a block with a given node. Used for source mapping.


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# File 'lib/sass/tree/visitors/to_css.rb', line 43

def for_node(node, attr_prefix = nil)
  return yield unless @source_mapping
  start_pos = Sass::Source::Position.new(@line, @offset)
  yield

  range_attr = attr_prefix ? :"#{attr_prefix}_source_range" : :source_range
  return if node.invisible? || !node.send(range_attr)
  source_range = node.send(range_attr)
  target_end_pos = Sass::Source::Position.new(@line, @offset)
  target_range = Sass::Source::Range.new(start_pos, target_end_pos, nil)
  @source_mapping.add(source_range, target_range)
end

#lstrip (protected)

lstrip the first output in the given block.


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# File 'lib/sass/tree/visitors/to_css.rb', line 102

def lstrip
  old_lstrip = @lstrip
  @lstrip = true
  yield
ensure
  @lstrip &&= old_lstrip
end

#output(s) (protected)

Add s to the output string and update the line and offset information accordingly.


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# File 'lib/sass/tree/visitors/to_css.rb', line 79

def output(s)
  if @lstrip
    s = s.gsub(/\A\s+/, "")
    @lstrip = false
  end

  newlines = s.count(NEWLINE)
  if newlines > 0
    @line += newlines
    @offset = s[s.rindex(NEWLINE)..-1].size
  else
    @offset += s.size
  end

  @result << s
end

#prepend!(prefix) (protected)

Prepend prefix to the output string.


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# File 'lib/sass/tree/visitors/to_css.rb', line 111

def prepend!(prefix)
  @result.insert 0, prefix
  return unless @source_mapping

  line_delta = prefix.count("\n")
  offset_delta = prefix.gsub(/.*\n/, '').size
  @source_mapping.shift_output_offsets(offset_delta)
  @source_mapping.shift_output_lines(line_delta)
end

#rstrip! (protected)

Strip all trailing whitespace from the output string.


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# File 'lib/sass/tree/visitors/to_css.rb', line 97

def rstrip!
  erase! @result.length - 1 - (@result.rindex(/[^\s]/) || -1)
end

#trailing_semicolon?Boolean (protected)

Returns:

  • (Boolean)

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# File 'lib/sass/tree/visitors/to_css.rb', line 56

def trailing_semicolon?
 @result.end_with?(";") && [email protected]_with?('\;')
end

#visit(node) ⇒ String

Runs the visitor on node.

Parameters:

Returns:

  • (String)

    The CSS output.


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# File 'lib/sass/tree/visitors/to_css.rb', line 25

def visit(node)
  super
rescue Sass::SyntaxError => e
  e.modify_backtrace(:filename => node.filename, :line => node.line)
  raise e
end

#visit_charset(node) (protected)


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# File 'lib/sass/tree/visitors/to_css.rb', line 155

def visit_charset(node)
  for_node(node) {output("@charset \"#{node.name}\";")}
end

#visit_comment(node) (protected)


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# File 'lib/sass/tree/visitors/to_css.rb', line 159

def visit_comment(node)
  return if node.invisible?
  spaces = ('  ' * [@tabs - node.resolved_value[/^ */].size, 0].max)
  output(spaces)

  content = node.resolved_value.split("\n").join("\n" + spaces)
  if node.type == :silent
    content.gsub!(%r{^(\s*)//(.*)$}) {"#{$1}/*#{$2} */"}
  end
  if (node.style == :compact || node.style == :compressed) && node.type != :loud
    content.gsub!(%r{\n +(\* *(?!/))?}, ' ')
  end
  for_node(node) {output(content)}
end

#visit_cssimport(node) (protected)


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# File 'lib/sass/tree/visitors/to_css.rb', line 255

def visit_cssimport(node)
  visit_directive(node)
end

#visit_directive(node) (protected)


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# File 'lib/sass/tree/visitors/to_css.rb', line 174

def visit_directive(node)
  was_in_directive = @in_directive
  tab_str = '  ' * @tabs
  if !node.has_children || node.children.empty?
    output(tab_str)
    for_node(node) {output(node.resolved_value)}
    if node.has_children
      output("#{' ' unless node.style == :compressed}{}")
    elsif node.children.empty?
      output(";")
    end
    return
  end

  @in_directive ||= !node.is_a?(Sass::Tree::MediaNode)
  output(tab_str) if node.style != :compressed
  for_node(node) {output(node.resolved_value)}
  output(node.style == :compressed ? "{" : " {")
  output(node.style == :compact ? ' ' : "\n") if node.style != :compressed

  had_children = true
  first = true
  node.children.each do |child|
    next if child.invisible?
    if node.style == :compact
      if child.is_a?(Sass::Tree::PropNode)
        with_tabs(first || !had_children ? 0 : @tabs + 1) do
          visit(child)
          output(' ')
        end
      else
        unless had_children
          erase! 1
          output "\n"
        end

        if first
          lstrip {with_tabs(@tabs + 1) {visit(child)}}
        else
          with_tabs(@tabs + 1) {visit(child)}
        end

        rstrip!
        output "\n"
      end
      had_children = child.has_children
      first = false
    elsif node.style == :compressed
      unless had_children
        output(";") unless trailing_semicolon?
      end
      with_tabs(0) {visit(child)}
      had_children = child.has_children
    else
      with_tabs(@tabs + 1) {visit(child)}
      output "\n"
    end
  end
  rstrip!
  if node.style == :compressed && trailing_semicolon?
    erase! 1
  end
  if node.style == :expanded
    output("\n#{tab_str}")
  elsif node.style != :compressed
    output(" ")
  end
  output("}")
ensure
  @in_directive = was_in_directive
end

#visit_keyframerule(node) (protected)


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# File 'lib/sass/tree/visitors/to_css.rb', line 375

def visit_keyframerule(node)
  visit_directive(node)
end

#visit_media(node) (protected)


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# File 'lib/sass/tree/visitors/to_css.rb', line 246

def visit_media(node)
  with_tabs(@tabs + node.tabs) {visit_directive(node)}
  output("\n") if node.style != :compressed && node.group_end
end

#visit_prop(node) (protected)


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# File 'lib/sass/tree/visitors/to_css.rb', line 259

def visit_prop(node)
  return if node.resolved_value.empty? && !node.custom_property?
  tab_str = '  ' * (@tabs + node.tabs)
  output(tab_str)
  for_node(node, :name) {output(node.resolved_name)}
  output(":")
  output(" ") unless node.style == :compressed || node.custom_property?
  for_node(node, :value) do
    output(if node.custom_property?
             format_custom_property_value(node)
           else
             node.resolved_value
           end)
  end
  output(";") unless node.style == :compressed
end

#visit_root(node) (protected)


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# File 'lib/sass/tree/visitors/to_css.rb', line 121

def visit_root(node)
  node.children.each do |child|
    next if child.invisible?
    visit(child)
    next if node.style == :compressed
    output "\n"
    next unless child.is_a?(Sass::Tree::DirectiveNode) && child.has_children && !child.bubbles?
    output "\n"
  end
  rstrip!
  if node.style == :compressed && trailing_semicolon?
    erase! 1
  end
  return "" if @result.empty?

  output "\n"

  unless @result.ascii_only?
    if node.style == :compressed
      # A byte order mark is sufficient to tell browsers that this
      # file is UTF-8 encoded, and will override any other detection
      # methods as per http://encoding.spec.whatwg.org/#decode-and-encode.
      prepend! "\uFEFF"
    else
      prepend! "@charset \"UTF-8\";\n"
    end
  end

  @result
rescue Sass::SyntaxError => e
  e.sass_template ||= node.template
  raise e
end

#visit_rule(node) (protected)


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# File 'lib/sass/tree/visitors/to_css.rb', line 276

def visit_rule(node)
  with_tabs(@tabs + node.tabs) do
    rule_separator = node.style == :compressed ? ',' : ', '
    line_separator =
      case node.style
      when :nested, :expanded; "\n"
      when :compressed; ""
      else; " "
      end
    rule_indent = '  ' * @tabs
    per_rule_indent, total_indent = if [:nested, :expanded].include?(node.style)
                                      [rule_indent, '']
                                    else
                                      ['', rule_indent]
                                    end

    joined_rules = node.resolved_rules.members.map do |seq|
      next if seq.invisible?
      rule_part = seq.to_s(style: node.style, placeholder: false)
      if node.style == :compressed
        rule_part.gsub!(/([^,])\s*\n\s*/m, '\1 ')
        rule_part.gsub!(/\s*([+>])\s*/m, '\1')
        rule_part.gsub!(/nth([^( ]*)\(([^)]*)\)/m) do |match|
          match.tr(" \t\n", "")
        end
        rule_part = Sass::Util.strip_except_escapes(rule_part)
      end
      rule_part
    end.compact.join(rule_separator)

    joined_rules.lstrip!
    joined_rules.gsub!(/\s*\n\s*/, "#{line_separator}#{per_rule_indent}")

    old_spaces = '  ' * @tabs
    if node.style != :compressed
      if node.options[:debug_info] && [email protected]_directive
        visit(debug_info_rule(node.debug_info, node.options))
        output "\n"
      elsif node.options[:trace_selectors]
        output("#{old_spaces}/* ")
        output(node.stack_trace.gsub("\n", "\n   #{old_spaces}"))
        output(" */\n")
      elsif node.options[:line_comments]
        output("#{old_spaces}/* line #{node.line}")

        if node.filename
          relative_filename =
            if node.options[:css_filename]
              begin
                Sass::Util.relative_path_from(
                  node.filename, File.dirname(node.options[:css_filename])).to_s
              rescue ArgumentError
                nil
              end
            end
          relative_filename ||= node.filename
          output(", #{relative_filename}")
        end

        output(" */\n")
      end
    end

    end_props, trailer, tabs = '', '', 0
    if node.style == :compact
      separator, end_props, bracket = ' ', ' ', ' { '
      trailer = "\n" if node.group_end
    elsif node.style == :compressed
      separator, bracket = ';', '{'
    else
      tabs = @tabs + 1
      separator, bracket = "\n", " {\n"
      trailer = "\n" if node.group_end
      end_props = (node.style == :expanded ? "\n" + old_spaces : ' ')
    end
    output(total_indent + per_rule_indent)
    for_node(node, :selector) {output(joined_rules)}
    output(bracket)

    with_tabs(tabs) do
      node.children.each_with_index do |child, i|
        if i > 0
          if separator.start_with?(";") && trailing_semicolon?
            erase! 1
          end
          output(separator)
        end
        visit(child)
      end
    end
    if node.style == :compressed && trailing_semicolon?
      erase! 1
    end

    output(end_props)
    output("}" + trailer)
  end
end

#visit_supports(node) (protected)


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# File 'lib/sass/tree/visitors/to_css.rb', line 251

def visit_supports(node)
  visit_media(node)
end

#with_tabs(tabs) (protected)


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# File 'lib/sass/tree/visitors/to_css.rb', line 34

def with_tabs(tabs)
  old_tabs, @tabs = @tabs, tabs
  yield
ensure
  @tabs = old_tabs
end