instiki/vendor/plugins/HTML5lib/lib/html5/html5parser.rb
2007-10-06 11:55:58 -05:00

249 lines
7.9 KiB
Ruby

require 'html5/constants'
require 'html5/tokenizer'
require 'html5/treebuilders/rexml'
Dir.glob(File.join(File.dirname(__FILE__), 'html5parser', '*_phase.rb')).each do |path|
require 'html5/html5parser/' + File.basename(path)
end
module HTML5
# Error in parsed document
class ParseError < Exception; end
class AssertionError < Exception; end
# HTML parser. Generates a tree structure from a stream of (possibly malformed) HTML
#
class HTMLParser
attr_accessor :phase, :first_start_tag, :inner_html, :last_phase, :insert_from_table
attr_reader :phases, :tokenizer, :tree, :errors
def self.parse(stream, options = {})
encoding = options.delete(:encoding)
new(options).parse(stream,encoding)
end
def self.parse_fragment(stream, options = {})
container = options.delete(:container) || 'div'
encoding = options.delete(:encoding)
new(options).parse_fragment(stream, container, encoding)
end
@@phases = %w( initial rootElement beforeHead inHead afterHead inBody inTable inCaption
inColumnGroup inTableBody inRow inCell inSelect afterBody inFrameset afterFrameset trailingEnd )
# :strict - raise an exception when a parse error is encountered
# :tree - a treebuilder class controlling the type of tree that will be
# returned. Built in treebuilders can be accessed through
# HTML5::TreeBuilders[treeType]
def initialize(options = {})
@strict = false
@errors = []
@tokenizer = HTMLTokenizer
@tree = TreeBuilders::REXML::TreeBuilder
options.each {|name, value| instance_variable_set("@#{name}", value) }
@lowercase_attr_name = nil unless instance_variables.include?("@lowercase_attr_name")
@lowercase_element_name = nil unless instance_variables.include?("@lowercase_element_name")
@tree = @tree.new
@phases = @@phases.inject({}) do |phases, phase_name|
phase_class_name = phase_name.sub(/(.)/) { $1.upcase } + 'Phase'
phases[phase_name.to_sym] = HTML5.const_get(phase_class_name).new(self, @tree)
phases
end
end
def _parse(stream, inner_html, encoding, container = 'div')
@tree.reset
@first_start_tag = false
@errors = []
@tokenizer = @tokenizer.class unless Class === @tokenizer
@tokenizer = @tokenizer.new(stream, :encoding => encoding,
:parseMeta => !inner_html, :lowercase_attr_name => @lowercase_attr_name, :lowercase_element_name => @lowercase_element_name)
if inner_html
case @inner_html = container.downcase
when 'title', 'textarea'
@tokenizer.content_model_flag = :RCDATA
when 'style', 'script', 'xmp', 'iframe', 'noembed', 'noframes', 'noscript'
@tokenizer.content_model_flag = :CDATA
when 'plaintext'
@tokenizer.content_model_flag = :PLAINTEXT
else
# content_model_flag already is PCDATA
@tokenizer.content_model_flag = :PCDATA
end
@phase = @phases[:rootElement]
@phase.insert_html_element
reset_insertion_mode
else
@inner_html = false
@phase = @phases[:initial]
end
# We only seem to have InBodyPhase testcases where the following is
# relevant ... need others too
@last_phase = nil
# XXX This is temporary for the moment so there isn't any other
# changes needed for the parser to work with the iterable tokenizer
@tokenizer.each do |token|
token = normalize_token(token)
method = 'process%s' % token[:type]
case token[:type]
when :Characters, :SpaceCharacters, :Comment
@phase.send method, token[:data]
when :StartTag
@phase.send method, token[:name], token[:data]
when :EndTag
@phase.send method, token[:name]
when :Doctype
@phase.send method, token[:name], token[:publicId],
token[:systemId], token[:correct]
else
parse_error(token[:data], token[:datavars])
end
end
# When the loop finishes it's EOF
@phase.process_eof
end
# Parse a HTML document into a well-formed tree
#
# stream - a filelike object or string containing the HTML to be parsed
#
# The optional encoding parameter must be a string that indicates
# the encoding. If specified, that encoding will be used,
# regardless of any BOM or later declaration (such as in a meta
# element)
def parse(stream, encoding=nil)
_parse(stream, false, encoding)
@tree.get_document
end
# Parse a HTML fragment into a well-formed tree fragment
# container - name of the element we're setting the inner_html property
# if set to nil, default to 'div'
#
# stream - a filelike object or string containing the HTML to be parsed
#
# The optional encoding parameter must be a string that indicates
# the encoding. If specified, that encoding will be used,
# regardless of any BOM or later declaration (such as in a meta
# element)
def parse_fragment(stream, container='div', encoding=nil)
_parse(stream, true, encoding, container)
@tree.get_fragment
end
def parse_error(code = 'XXX-undefined-error', data = {})
# XXX The idea is to make data mandatory.
@errors.push([@tokenizer.stream.position, code, data])
raise ParseError if @strict
end
# HTML5 specific normalizations to the token stream
def normalize_token(token)
if token[:type] == :EmptyTag
# When a solidus (/) is encountered within a tag name what happens
# depends on whether the current tag name matches that of a void
# element. If it matches a void element atheists did the wrong
# thing and if it doesn't it's wrong for everyone.
unless VOID_ELEMENTS.include?(token[:name])
parse_error("incorrectly-placed-solidus")
end
token[:type] = :StartTag
end
if token[:type] == :StartTag
token[:name] = token[:name].downcase
# We need to remove the duplicate attributes and convert attributes
# to a dict so that [["x", "y"], ["x", "z"]] becomes {"x": "y"}
unless token[:data].empty?
data = token[:data].reverse.map {|attr, value| [attr.downcase, value] }
token[:data] = Hash[*data.flatten]
end
elsif token[:type] == :EndTag
parse_error("attributes-in-end-tag") unless token[:data].empty?
token[:name] = token[:name].downcase
end
token
end
@@new_modes = {
'select' => :inSelect,
'td' => :inCell,
'th' => :inCell,
'tr' => :inRow,
'tbody' => :inTableBody,
'thead' => :inTableBody,
'tfoot' => :inTableBody,
'caption' => :inCaption,
'colgroup' => :inColumnGroup,
'table' => :inTable,
'head' => :inBody,
'body' => :inBody,
'frameset' => :inFrameset
}
def reset_insertion_mode
# The name of this method is mostly historical. (It's also used in the
# specification.)
last = false
@tree.open_elements.reverse.each do |node|
node_name = node.name
if node == @tree.open_elements.first
last = true
unless ['td', 'th'].include?(node_name)
# XXX
# assert @inner_html
node_name = @inner_html
end
end
# Check for conditions that should only happen in the inner_html
# case
if ['select', 'colgroup', 'head', 'frameset'].include?(node_name)
# XXX
# assert @inner_html
end
if @@new_modes.has_key?(node_name)
@phase = @phases[@@new_modes[node_name]]
elsif node_name == 'html'
@phase = @phases[@tree.head_pointer.nil?? :beforeHead : :afterHead]
elsif last
@phase = @phases[:inBody]
else
next
end
break
end
end
def _(string); string; end
end
end