instiki/vendor/plugins/HTML5lib/lib/html5lib/serializer.rb
2007-06-06 08:44:57 -05:00

418 lines
16 KiB
Ruby

require 'html5lib/constants'
module HTML5lib
class Filter
include Enumerable
def initialize(source)
@source = source
end
end
class OptionalTagFilter < Filter
def slider
previous1 = previous2 = nil
@source.each do |token|
yield previous2, previous1, token if previous1 != nil
previous2 = previous1
previous1 = token
end
yield previous2, previous1, nil
end
def each
slider do |previous, token, nexttok|
type = token[:type]
if type == :StartTag
yield token unless token[:data].empty? and is_optional_start(token[:name], previous, nexttok)
elsif type == :EndTag
yield token unless is_optional_end(token[:name], nexttok)
else
yield token
end
end
end
def is_optional_start(tagname, previous, nexttok)
type = nexttok ? nexttok[:type] : nil
if tagname == 'html'
# An html element's start tag may be omitted if the first thing
# inside the html element is not a space character or a comment.
return ![:Comment, :SpaceCharacters].include?(type)
elsif tagname == 'head'
# A head element's start tag may be omitted if the first thing
# inside the head element is an element.
return type == :StartTag
elsif tagname == 'body'
# A body element's start tag may be omitted if the first thing
# inside the body element is not a space character or a comment,
# except if the first thing inside the body element is a script
# or style element and the node immediately preceding the body
# element is a head element whose end tag has been omitted.
if [:Comment, :SpaceCharacters].include?(type)
return false
elsif type == :StartTag
# XXX: we do not look at the preceding event, so we never omit
# the body element's start tag if it's followed by a script or
# a style element.
return !%w[script style].include?(nexttok[:name])
else
return true
end
elsif tagname == 'colgroup'
# A colgroup element's start tag may be omitted if the first thing
# inside the colgroup element is a col element, and if the element
# is not immediately preceeded by another colgroup element whose
# end tag has been omitted.
if type == :StartTag
# XXX: we do not look at the preceding event, so instead we never
# omit the colgroup element's end tag when it is immediately
# followed by another colgroup element. See is_optional_end.
return nexttok[:name] == "col"
else
return false
end
elsif tagname == 'tbody'
# A tbody element's start tag may be omitted if the first thing
# inside the tbody element is a tr element, and if the element is
# not immediately preceeded by a tbody, thead, or tfoot element
# whose end tag has been omitted.
if type == :StartTag
# omit the thead and tfoot elements' end tag when they are
# immediately followed by a tbody element. See is_optional_end.
if previous and previous[:type] == :EndTag and \
%w(tbody thead tfoot).include?(previous[:name])
return false
end
return nexttok[:name] == 'tr'
else
return false
end
end
return false
end
def is_optional_end(tagname, nexttok)
type = nexttok ? nexttok[:type] : nil
if %w[html head body].include?(tagname)
# An html element's end tag may be omitted if the html element
# is not immediately followed by a space character or a comment.
return ![:Comment, :SpaceCharacters].include?(type)
elsif %w[li optgroup option tr].include?(tagname)
# A li element's end tag may be omitted if the li element is
# immediately followed by another li element or if there is
# no more content in the parent element.
# An optgroup element's end tag may be omitted if the optgroup
# element is immediately followed by another optgroup element,
# or if there is no more content in the parent element.
# An option element's end tag may be omitted if the option
# element is immediately followed by another option element,
# or if there is no more content in the parent element.
# A tr element's end tag may be omitted if the tr element is
# immediately followed by another tr element, or if there is
# no more content in the parent element.
if type == :StartTag
return nexttok[:name] == tagname
else
return type == :EndTag || type == nil
end
elsif %w(dt dd).include?(tagname)
# A dt element's end tag may be omitted if the dt element is
# immediately followed by another dt element or a dd element.
# A dd element's end tag may be omitted if the dd element is
# immediately followed by another dd element or a dt element,
# or if there is no more content in the parent element.
if type == :StartTag
return %w(dt dd).include?(nexttok[:name])
elsif tagname == 'dd'
return type == :EndTag || type == nil
else
return false
end
elsif tagname == 'p'
# A p element's end tag may be omitted if the p element is
# immediately followed by an address, blockquote, dl, fieldset,
# form, h1, h2, h3, h4, h5, h6, hr, menu, ol, p, pre, table,
# or ul element, or if there is no more content in the parent
# element.
if type == :StartTag
return %w(address blockquote dl fieldset form h1 h2 h3 h4 h5
h6 hr menu ol p pre table ul).include?(nexttok[:name])
else
return type == :EndTag || type == nil
end
elsif tagname == 'colgroup'
# A colgroup element's end tag may be omitted if the colgroup
# element is not immediately followed by a space character or
# a comment.
if [:Comment, :SpaceCharacters].include?(type)
return false
elsif type == :StartTag
# XXX: we also look for an immediately following colgroup
# element. See is_optional_start.
return nexttok[:name] != 'colgroup'
else
return true
end
elsif %w(thead tbody).include? tagname
# A thead element's end tag may be omitted if the thead element
# is immediately followed by a tbody or tfoot element.
# A tbody element's end tag may be omitted if the tbody element
# is immediately followed by a tbody or tfoot element, or if
# there is no more content in the parent element.
# A tfoot element's end tag may be omitted if the tfoot element
# is immediately followed by a tbody element, or if there is no
# more content in the parent element.
# XXX: we never omit the end tag when the following element is
# a tbody. See is_optional_start.
if type == :StartTag
return %w(tbody tfoot).include?(nexttok[:name])
elsif tagname == 'tbody'
return (type == :EndTag or type == nil)
else
return false
end
elsif tagname == 'tfoot'
# A tfoot element's end tag may be omitted if the tfoot element
# is immediately followed by a tbody element, or if there is no
# more content in the parent element.
# XXX: we never omit the end tag when the following element is
# a tbody. See is_optional_start.
if type == :StartTag
return nexttok[:name] == 'tbody'
else
return type == :EndTag || type == nil
end
elsif %w(td th).include? tagname
# A td element's end tag may be omitted if the td element is
# immediately followed by a td or th element, or if there is
# no more content in the parent element.
# A th element's end tag may be omitted if the th element is
# immediately followed by a td or th element, or if there is
# no more content in the parent element.
if type == :StartTag
return %w(td th).include?(nexttok[:name])
else
return type == :EndTag || type == nil
end
end
return false
end
end
class HTMLSerializer
CDATA_ELEMENTS = %w[style script xmp iframe noembed noframes noscript]
def self.serialize(stream, options = {})
new(options).serialize(stream)
end
def initialize(options={})
@quote_attr_values = false
@quote_char = '"'
@use_best_quote_char = true
@minimize_boolean_attributes = true
@use_trailing_solidus = false
@space_before_trailing_solidus = true
@omit_optional_tags = true
@sanitize = false
@strip_whitespace = false
@inject_meta_charset = true
options.each do |name, value|
next unless %w(quote_attr_values quote_char use_best_quote_char
minimize_boolean_attributes use_trailing_solidus
space_before_trailing_solidus omit_optional_tags sanitize
strip_whitespace inject_meta_charset).include? name.to_s
@use_best_quote_char = false if name.to_s == 'quote_char'
instance_variable_set("@#{name}", value)
end
@errors = []
end
def serialize(treewalker, encoding=nil)
in_cdata = false
@errors = []
if encoding and @inject_meta_charset
treewalker = filter_inject_meta_charset(treewalker, encoding)
end
if @strip_whitespace
treewalker = filter_whitespace(treewalker)
end
if @sanitize
require 'html5lib/sanitizer'
treewalker = HTMLSanitizeFilter.new(treewalker)
end
if @omit_optional_tags
treewalker = OptionalTagFilter.new(treewalker)
end
result = []
treewalker.each do |token|
type = token[:type]
if type == :Doctype
doctype = "<!DOCTYPE %s>" % token[:name]
if encoding
result << doctype.encode(encoding)
else
result << doctype
end
elsif [:Characters, :SpaceCharacters].include? type
if type == :SpaceCharacters or in_cdata
if in_cdata and token[:data].include?("</")
serializeError(_("Unexpected </ in CDATA"))
end
if encoding
result << token[:data].encode(encoding, errors || "strict")
else
result << token[:data]
end
elsif encoding
result << token[:data].replace("&", "&amp;") \
.encode(encoding, unicode_encode_errors)
else
result << token[:data] \
.gsub("&", "&amp;") \
.gsub("<", "&lt;") \
.gsub(">", "&gt;")
end
elsif [:StartTag, :EmptyTag].include? type
name = token[:name]
if CDATA_ELEMENTS.include?(name)
in_cdata = true
elsif in_cdata
serializeError(_("Unexpected child element of a CDATA element"))
end
attrs = token[:data].to_a
attrs.sort()
attributes = []
for k,v in attrs
if encoding
k = k.encode(encoding)
end
attributes << ' '
attributes << k
if not @minimize_boolean_attributes or \
(!(BOOLEAN_ATTRIBUTES[name]||[]).include?(k) \
and !BOOLEAN_ATTRIBUTES[:global].include?(k))
attributes << "="
if @quote_attr_values or v.empty?
quote_attr = true
else
quote_attr = (SPACE_CHARACTERS + %w(< > " ')).any? {|c| v.include?(c)}
end
v = v.gsub("&", "&amp;")
if encoding
v = v.encode(encoding, unicode_encode_errors)
end
if quote_attr
quote_char = @quote_char
if @use_best_quote_char
if v.index("'") and !v.index('"')
quote_char = '"'
elsif v.index('"') and !v.index("'")
quote_char = "'"
end
end
if quote_char == "'"
v = v.gsub("'", "&#39;")
else
v = v.gsub('"', "&quot;")
end
attributes << quote_char << v << quote_char
else
attributes << v
end
end
end
if VOID_ELEMENTS.include?(name) and @use_trailing_solidus
if @space_before_trailing_solidus
attributes << " /"
else
attributes << "/"
end
end
if encoding
result << "<%s%s>" % [name.encode(encoding), attributes.join('')]
else
result << "<%s%s>" % [name, attributes.join('')]
end
elsif type == :EndTag
name = token[:name]
if CDATA_ELEMENTS.include?(name)
in_cdata = false
elsif in_cdata
serializeError(_("Unexpected child element of a CDATA element"))
end
end_tag = "</%s>" % name
if encoding
end_tag = end_tag.encode(encoding)
end
result << end_tag
elsif type == :Comment
data = token[:data]
if data.index("--")
serializeError(_("Comment contains --"))
end
comment = "<!--%s-->" % token[:data]
if encoding
comment = comment.encode(encoding, unicode_encode_errors)
end
result << comment
else
serializeError(token[:data])
end
end
result.join('')
end
def render(treewalker, encoding=nil)
if encoding
return "".join(list(serialize(treewalker, encoding)))
else
return "".join(list(serialize(treewalker)))
end
end
def serializeError(data="XXX ERROR MESSAGE NEEDED")
# XXX The idea is to make data mandatory.
@errors.push(data)
if @strict
raise SerializeError
end
end
def filter_inject_meta_charset(treewalker, encoding)
done = false
for token in treewalker
if not done and token[:type] == :StartTag \
and token[:name].lower() == "head"
yield({:type => :EmptyTag, :name => "meta", \
:data => {"charset" => encoding}})
end
yield token
end
end
def filter_whitespace(treewalker)
raise NotImplementedError
end
end
# Error in serialized tree
class SerializeError < Exception
end
end