require 'strscan'
module Haml
class Parser
include Haml::Util
# Designates an XHTML/XML element.
ELEMENT = ?%
# Designates a `<div>` element with the given class.
DIV_CLASS = ?.
# Designates a `<div>` element with the given id.
DIV_ID = ?#
# Designates an XHTML/XML comment.
COMMENT = ?/
# Designates an XHTML doctype or script that is never HTML-escaped.
DOCTYPE = ?!
# Designates script, the result of which is output.
SCRIPT = ?=
# Designates script that is always HTML-escaped.
SANITIZE = ?&
# Designates script, the result of which is flattened and output.
FLAT_SCRIPT = ?~
# Designates script which is run but not output.
SILENT_SCRIPT = ?-
# When following SILENT_SCRIPT, designates a comment that is not output.
SILENT_COMMENT = ?#
# Designates a non-parsed line.
ESCAPE = ?\\
# Designates a block of filtered text.
FILTER = ?:
# Designates a non-parsed line. Not actually a character.
PLAIN_TEXT = -1
# Keeps track of the ASCII values of the characters that begin a
# specially-interpreted line.
SPECIAL_CHARACTERS = [
ELEMENT,
DIV_CLASS,
DIV_ID,
COMMENT,
DOCTYPE,
SCRIPT,
SANITIZE,
FLAT_SCRIPT,
SILENT_SCRIPT,
ESCAPE,
FILTER
]
# The value of the character that designates that a line is part
# of a multiline string.
MULTILINE_CHAR_VALUE = ?|
MID_BLOCK_KEYWORDS = %w[else elsif rescue ensure end when]
START_BLOCK_KEYWORDS = %w[if begin case]
# Try to parse assignments to block starters as best as possible
START_BLOCK_KEYWORD_REGEX = /(?:\w+(?:,\s*\w+)*\s*=\s*)?(#{START_BLOCK_KEYWORDS.join('|')})/
BLOCK_KEYWORD_REGEX = /^-\s*(?:(#{MID_BLOCK_KEYWORDS.join('|')})|#{START_BLOCK_KEYWORD_REGEX.source})\b/
# The Regex that matches a Doctype command.
DOCTYPE_REGEX = /(\d(?:\.\d)?)?[\s]*([a-z]*)\s*([^ ]+)?/i
# The Regex that matches a literal string or symbol value
LITERAL_VALUE_REGEX = /:(\w*)|(["'])((?![\\#]|\2).|\\.)*\2/
def initialize(template, options)
# :eod is a special end-of-document marker
@template = (template.rstrip).split(/\r\n|\r|\n/) + [:eod, :eod]
@options = options
@flat = false
@index = 0
@template_index = 0
@template_tabs = 0
end
def parse
@root = @parent = ParseNode.new(:root)
@haml_comment = false
@indentation = nil
@line = next_line
raise SyntaxError.new("Indenting at the beginning of the document is illegal.", @line.index) if @line.tabs != 0
while next_line
process_indent(@line) unless @line.text.empty?
if flat?
text = @line.full.dup
text = "" unless text.gsub!(/^#{@flat_spaces}/, '')
@filter_buffer << "#{text}\n"
@line = @next_line
next
end
@tab_up = nil
process_line(@line.text, @line.index) unless @line.text.empty? || @haml_comment
if @parent.type != :haml_comment && (block_opened? || @tab_up)
@template_tabs += 1
@parent = @parent.children.last
end
if !@haml_comment && !flat? && @next_line.tabs - @line.tabs > 1
raise SyntaxError.new("The line was indented #{@next_line.tabs - @line.tabs} levels deeper than the previous line.", @next_line.index)
end
@line = @next_line
end
# Close all the open tags
close until @parent.type == :root
@root
rescue Haml::Error => e
e.backtrace.unshift "#{@options[:filename]}:#{(e.line ? e.line + 1 : @index) + @options[:line] - 1}"
raise
end
private
# @private
class Line < Struct.new(:text, :unstripped, :full, :index, :compiler, :eod)
alias_method :eod?, :eod
# @private
def tabs
line = self
@tabs ||= compiler.instance_eval do
break 0 if line.text.empty? || !(whitespace = line.full[/^\s+/])
if @indentation.nil?
@indentation = whitespace
if @indentation.include?(?\s) && @indentation.include?(?\t)
raise SyntaxError.new("Indentation can't use both tabs and spaces.", line.index)
end
@flat_spaces = @indentation * (@template_tabs+1) if flat?
break 1
end
tabs = whitespace.length / @indentation.length
break tabs if whitespace == @indentation * tabs
break @template_tabs + 1 if flat? && whitespace =~ /^#{@flat_spaces}/
raise SyntaxError.new(<<END.strip.gsub("\n", ' '), line.index)
Inconsistent indentation: #{Haml::Util.human_indentation whitespace, true} used for indentation,
but the rest of the document was indented using #{Haml::Util.human_indentation @indentation}.
END
end
end
end
# @private
class ParseNode < Struct.new(:type, :line, :value, :parent, :children)
def initialize(*args)
super
self.children ||= []
end
def inspect
text = "(#{type} #{value.inspect}"
children.each {|c| text << "\n" << c.inspect.gsub(/^/, " ")}
text + ")"
end
end
# Processes and deals with lowering indentation.
def process_indent(line)
return unless line.tabs <= @template_tabs && @template_tabs > 0
to_close = @template_tabs - line.tabs
to_close.times {|i| close unless to_close - 1 - i == 0 && mid_block_keyword?(line.text)}
end
# Processes a single line of Haml.
#
# This method doesn't return anything; it simply processes the line and
# adds the appropriate code to `@precompiled`.
def process_line(text, index)
@index = index + 1
case text[0]
when DIV_CLASS; push div(text)
when DIV_ID
return push plain(text) if text[1] == ?{
push div(text)
when ELEMENT; push tag(text)
when COMMENT; push comment(text[1..-1].strip)
when SANITIZE
return push plain(text[3..-1].strip, :escape_html) if text[1..2] == "=="
return push script(text[2..-1].strip, :escape_html) if text[1] == SCRIPT
return push flat_script(text[2..-1].strip, :escape_html) if text[1] == FLAT_SCRIPT
return push plain(text[1..-1].strip, :escape_html) if text[1] == ?\s
push plain(text)
when SCRIPT
return push plain(text[2..-1].strip) if text[1] == SCRIPT
push script(text[1..-1])
when FLAT_SCRIPT; push flat_script(text[1..-1])
when SILENT_SCRIPT; push silent_script(text)
when FILTER; push filter(text[1..-1].downcase)
when DOCTYPE
return push doctype(text) if text[0...3] == '!!!'
return push plain(text[3..-1].strip, false) if text[1..2] == "=="
return push script(text[2..-1].strip, false) if text[1] == SCRIPT
return push flat_script(text[2..-1].strip, false) if text[1] == FLAT_SCRIPT
return push plain(text[1..-1].strip, false) if text[1] == ?\s
push plain(text)
when ESCAPE; push plain(text[1..-1])
else; push plain(text)
end
end
def block_keyword(text)
return unless keyword = text.scan(BLOCK_KEYWORD_REGEX)[0]
keyword[0] || keyword[1]
end
def mid_block_keyword?(text)
MID_BLOCK_KEYWORDS.include?(block_keyword(text))
end
def push(node)
@parent.children << node
node.parent = @parent
end
def plain(text, escape_html = nil)
if block_opened?
raise SyntaxError.new("Illegal nesting: nesting within plain text is illegal.", @next_line.index)
end
unless contains_interpolation?(text)
return ParseNode.new(:plain, @index, :text => text)
end
escape_html = @options[:escape_html] if escape_html.nil?
script(unescape_interpolation(text, escape_html), false)
end
def script(text, escape_html = nil, preserve = false)
raise SyntaxError.new("There's no Ruby code for = to evaluate.") if text.empty?
text = handle_ruby_multiline(text)
escape_html = @options[:escape_html] if escape_html.nil?
ParseNode.new(:script, @index, :text => text, :escape_html => escape_html,
:preserve => preserve)
end
def flat_script(text, escape_html = nil)
raise SyntaxError.new("There's no Ruby code for ~ to evaluate.") if text.empty?
script(text, escape_html, :preserve)
end
def silent_script(text)
return haml_comment(text[2..-1]) if text[1] == SILENT_COMMENT
raise SyntaxError.new(<<END.rstrip, @index - 1) if text[1..-1].strip == "end"
You don't need to use "- end" in Haml. Un-indent to close a block:
- if foo?
%strong Foo!
- else
Not foo.
%p This line is un-indented, so it isn't part of the "if" block
END
text = handle_ruby_multiline(text)
keyword = block_keyword(text)
@tab_up = ["if", "case"].include?(keyword)
ParseNode.new(:silent_script, @index,
:text => text[1..-1], :keyword => keyword)
end
def haml_comment(text)
@haml_comment = block_opened?
ParseNode.new(:haml_comment, @index, :text => text)
end
def tag(line)
tag_name, attributes, attributes_hashes, object_ref, nuke_outer_whitespace,
nuke_inner_whitespace, action, value, last_line = parse_tag(line)
preserve_tag = @options[:preserve].include?(tag_name)
nuke_inner_whitespace ||= preserve_tag
preserve_tag = false if @options[:ugly]
escape_html = (action == '&' || (action != '!' && @options[:escape_html]))
case action
when '/'; self_closing = true
when '~'; parse = preserve_script = true
when '='
parse = true
if value[0] == ?=
value = unescape_interpolation(value[1..-1].strip, escape_html)
escape_html = false
end
when '&', '!'
if value[0] == ?= || value[0] == ?~
parse = true
preserve_script = (value[0] == ?~)
if value[1] == ?=
value = unescape_interpolation(value[2..-1].strip, escape_html)
escape_html = false
else
value = value[1..-1].strip
end
elsif contains_interpolation?(value)
value = unescape_interpolation(value, escape_html)
parse = true
escape_html = false
end
else
if contains_interpolation?(value)
value = unescape_interpolation(value, escape_html)
parse = true
escape_html = false
end
end
attributes = Parser.parse_class_and_id(attributes)
attributes_list = []
if attributes_hashes[:new]
static_attributes, attributes_hash = attributes_hashes[:new]
Buffer.merge_attrs(attributes, static_attributes) if static_attributes
attributes_list << attributes_hash
end
if attributes_hashes[:old]
static_attributes = parse_static_hash(attributes_hashes[:old])
Buffer.merge_attrs(attributes, static_attributes) if static_attributes
attributes_list << attributes_hashes[:old] unless static_attributes || @options[:suppress_eval]
end
attributes_list.compact!
raise SyntaxError.new("Illegal nesting: nesting within a self-closing tag is illegal.", @next_line.index) if block_opened? && self_closing
raise SyntaxError.new("There's no Ruby code for #{action} to evaluate.", last_line - 1) if parse && value.empty?
raise SyntaxError.new("Self-closing tags can't have content.", last_line - 1) if self_closing && !value.empty?
if block_opened? && !value.empty? && !is_ruby_multiline?(value)
raise SyntaxError.new("Illegal nesting: content can't be both given on the same line as %#{tag_name} and nested within it.", @next_line.index)
end
self_closing ||= !!(!block_opened? && value.empty? && @options[:autoclose].any? {|t| t === tag_name})
value = nil if value.empty? && (block_opened? || self_closing)
value = handle_ruby_multiline(value) if parse
ParseNode.new(:tag, @index, :name => tag_name, :attributes => attributes,
:attributes_hashes => attributes_list, :self_closing => self_closing,
:nuke_inner_whitespace => nuke_inner_whitespace,
:nuke_outer_whitespace => nuke_outer_whitespace, :object_ref => object_ref,
:escape_html => escape_html, :preserve_tag => preserve_tag,
:preserve_script => preserve_script, :parse => parse, :value => value)
end
# Renders a line that creates an XHTML tag and has an implicit div because of
# `.` or `#`.
def div(line)
tag('%div' + line)
end
# Renders an XHTML comment.
def comment(line)
conditional, line = balance(line, ?[, ?]) if line[0] == ?[
line.strip!
conditional << ">" if conditional
if block_opened? && !line.empty?
raise SyntaxError.new('Illegal nesting: nesting within a tag that already has content is illegal.', @next_line.index)
end
ParseNode.new(:comment, @index, :conditional => conditional, :text => line)
end
# Renders an XHTML doctype or XML shebang.
def doctype(line)
raise SyntaxError.new("Illegal nesting: nesting within a header command is illegal.", @next_line.index) if block_opened?
version, type, encoding = line[3..-1].strip.downcase.scan(DOCTYPE_REGEX)[0]
ParseNode.new(:doctype, @index, :version => version, :type => type, :encoding => encoding)
end
def filter(name)
raise Error.new("Invalid filter name \":#{name}\".") unless name =~ /^\w+$/
@filter_buffer = String.new
if filter_opened?
@flat = true
# If we don't know the indentation by now, it'll be set in Line#tabs
@flat_spaces = @indentation * (@template_tabs+1) if @indentation
end
ParseNode.new(:filter, @index, :name => name, :text => @filter_buffer)
end
def close
node, @parent = @parent, @parent.parent
@template_tabs -= 1
send("close_#{node.type}", node) if respond_to?("close_#{node.type}", :include_private)
end
def close_filter(_)
@flat = false
@flat_spaces = nil
@filter_buffer = nil
end
def close_haml_comment(_)
@haml_comment = false
end
def close_silent_script(node)
# Post-process case statements to normalize the nesting of "when" clauses
return unless node.value[:keyword] == "case"
return unless first = node.children.first
return unless first.type == :silent_script && first.value[:keyword] == "when"
return if first.children.empty?
# If the case node has a "when" child with children, it's the
# only child. Then we want to put everything nested beneath it
# beneath the case itself (just like "if").
node.children = [first, *first.children]
first.children = []
end
# This is a class method so it can be accessed from {Haml::Helpers}.
#
# Iterates through the classes and ids supplied through `.`
# and `#` syntax, and returns a hash with them as attributes,
# that can then be merged with another attributes hash.
def self.parse_class_and_id(list)
attributes = {}
list.scan(/([#.])([-:_a-zA-Z0-9]+)/) do |type, property|
case type
when '.'
if attributes['class']
attributes['class'] += " "
else
attributes['class'] = ""
end
attributes['class'] += property
when '#'; attributes['id'] = property
end
end
attributes
end
def parse_static_hash(text)
attributes = {}
scanner = StringScanner.new(text)
scanner.scan(/\s+/)
until scanner.eos?
return unless key = scanner.scan(LITERAL_VALUE_REGEX)
return unless scanner.scan(/\s*=>\s*/)
return unless value = scanner.scan(LITERAL_VALUE_REGEX)
return unless scanner.scan(/\s*(?:,|$)\s*/)
attributes[eval(key).to_s] = eval(value).to_s
end
attributes
end
# Parses a line into tag_name, attributes, attributes_hash, object_ref, action, value
def parse_tag(line)
raise SyntaxError.new("Invalid tag: \"#{line}\".") unless match = line.scan(/%([-:\w]+)([-:\w\.\#]*)(.*)/)[0]
tag_name, attributes, rest = match
raise SyntaxError.new("Illegal element: classes and ids must have values.") if attributes =~ /[\.#](\.|#|\z)/
new_attributes_hash = old_attributes_hash = last_line = nil
object_ref = "nil"
attributes_hashes = {}
while rest
case rest[0]
when ?{
break if old_attributes_hash
old_attributes_hash, rest, last_line = parse_old_attributes(rest)
attributes_hashes[:old] = old_attributes_hash
when ?(
break if new_attributes_hash
new_attributes_hash, rest, last_line = parse_new_attributes(rest)
attributes_hashes[:new] = new_attributes_hash
when ?[
break unless object_ref == "nil"
object_ref, rest = balance(rest, ?[, ?])
else; break
end
end
if rest
nuke_whitespace, action, value = rest.scan(/(<>|><|[><])?([=\/\~&!])?(.*)?/)[0]
nuke_whitespace ||= ''
nuke_outer_whitespace = nuke_whitespace.include? '>'
nuke_inner_whitespace = nuke_whitespace.include? '<'
end
if @options[:remove_whitespace]
nuke_outer_whitespace = true
nuke_inner_whitespace = true
end
value = value.to_s.strip
[tag_name, attributes, attributes_hashes, object_ref, nuke_outer_whitespace,
nuke_inner_whitespace, action, value, last_line || @index]
end
def parse_old_attributes(line)
line = line.dup
last_line = @index
begin
attributes_hash, rest = balance(line, ?{, ?})
rescue SyntaxError => e
if line.strip[-1] == ?, && e.message == "Unbalanced brackets."
line << "\n" << @next_line.text
last_line += 1
next_line
retry
end
raise e
end
attributes_hash = attributes_hash[1...-1] if attributes_hash
return attributes_hash, rest, last_line
end
def parse_new_attributes(line)
line = line.dup
scanner = StringScanner.new(line)
last_line = @index
attributes = {}
scanner.scan(/\(\s*/)
loop do
name, value = parse_new_attribute(scanner)
break if name.nil?
if name == false
text = (Haml::Util.balance(line, ?(, ?)) || [line]).first
raise Haml::SyntaxError.new("Invalid attribute list: #{text.inspect}.", last_line - 1)
end
attributes[name] = value
scanner.scan(/\s*/)
if scanner.eos?
line << " " << @next_line.text
last_line += 1
next_line
scanner.scan(/\s*/)
end
end
static_attributes = {}
dynamic_attributes = "{"
attributes.each do |name, (type, val)|
if type == :static
static_attributes[name] = val
else
dynamic_attributes << inspect_obj(name) << " => " << val << ","
end
end
dynamic_attributes << "}"
dynamic_attributes = nil if dynamic_attributes == "{}"
return [static_attributes, dynamic_attributes], scanner.rest, last_line
end
def parse_new_attribute(scanner)
unless name = scanner.scan(/[-:\w]+/)
return if scanner.scan(/\)/)
return false
end
scanner.scan(/\s*/)
return name, [:static, true] unless scanner.scan(/=/) #/end
scanner.scan(/\s*/)
unless quote = scanner.scan(/["']/)
return false unless var = scanner.scan(/(@@?|\$)?\w+/)
return name, [:dynamic, var]
end
re = /((?:\\.|\#(?!\{)|[^#{quote}\\#])*)(#{quote}|#\{)/
content = []
loop do
return false unless scanner.scan(re)
content << [:str, scanner[1].gsub(/\\(.)/, '\1')]
break if scanner[2] == quote
content << [:ruby, balance(scanner, ?{, ?}, 1).first[0...-1]]
end
return name, [:static, content.first[1]] if content.size == 1
return name, [:dynamic,
'"' + content.map {|(t, v)| t == :str ? inspect_obj(v)[1...-1] : "\#{#{v}}"}.join + '"']
end
def raw_next_line
text = @template.shift
return unless text
index = @template_index
@template_index += 1
return text, index
end
def next_line
text, index = raw_next_line
return unless text
# :eod is a special end-of-document marker
line =
if text == :eod
Line.new '-#', '-#', '-#', index, self, true
else
Line.new text.strip, text.lstrip.chomp, text, index, self, false
end
# `flat?' here is a little outdated,
# so we have to manually check if either the previous or current line
# closes the flat block, as well as whether a new block is opened.
line_defined = instance_variable_defined?('@line')
@line.tabs if line_defined
unless (flat? && !closes_flat?(line) && !closes_flat?(@line)) ||
(line_defined && @line.text[0] == ?: && line.full =~ %r[^#{@line.full[/^\s+/]}\s])
return next_line if line.text.empty?
handle_multiline(line)
end
@next_line = line
end
def closes_flat?(line)
line && !line.text.empty? && line.full !~ /^#{@flat_spaces}/
end
def un_next_line(line)
@template.unshift line
@template_index -= 1
end
def handle_multiline(line)
return unless is_multiline?(line.text)
line.text.slice!(-1)
while new_line = raw_next_line.first
break if new_line == :eod
next if new_line.strip.empty?
break unless is_multiline?(new_line.strip)
line.text << new_line.strip[0...-1]
end
un_next_line new_line
end
# Checks whether or not `line` is in a multiline sequence.
def is_multiline?(text)
text && text.length > 1 && text[-1] == MULTILINE_CHAR_VALUE && text[-2] == ?\s
end
def handle_ruby_multiline(text)
text = text.rstrip
return text unless is_ruby_multiline?(text)
un_next_line @next_line.full
begin
new_line = raw_next_line.first
break if new_line == :eod
next if new_line.strip.empty?
text << " " << new_line.strip
end while is_ruby_multiline?(new_line.strip)
next_line
text
end
# `text' is a Ruby multiline block if it:
# - ends with a comma
# - but not "?," which is a character literal
# (however, "x?," is a method call and not a literal)
# - and not "?\," which is a character literal
#
def is_ruby_multiline?(text)
text && text.length > 1 && text[-1] == ?, &&
!((text[-3..-2] =~ /\W\?/) || text[-3..-2] == "?\\")
end
def balance(*args)
res = Haml::Util.balance(*args)
return res if res
raise SyntaxError.new("Unbalanced brackets.")
end
def block_opened?
@next_line.tabs > @line.tabs
end
# Same semantics as block_opened?, except that block_opened? uses Line#tabs,
# which doesn't interact well with filter lines
def filter_opened?
@next_line.full =~ (@indentation ? /^#{@indentation * @template_tabs}/ : /^\s/)
end
def flat?
@flat
end
end
end