require 'rexml/parseexception'
require 'rexml/source'
module REXML
module Parsers
# = Using the Pull Parser
# <em>This API is experimental, and subject to change.</em>
# parser = PullParser.new( "<a>text<b att='val'/>txet</a>" )
# while parser.has_next?
# res = parser.next
# puts res[1]['att'] if res.start_tag? and res[0] == 'b'
# end
# See the PullEvent class for information on the content of the results.
# The data is identical to the arguments passed for the various events to
# the StreamListener API.
#
# Notice that:
# parser = PullParser.new( "<a>BAD DOCUMENT" )
# while parser.has_next?
# res = parser.next
# raise res[1] if res.error?
# end
#
# Nat Price gave me some good ideas for the API.
class BaseParser
NCNAME_STR= '[\w:][\-\w\d.]*'
NAME_STR= "(?:#{NCNAME_STR}:)?#{NCNAME_STR}"
NAMECHAR = '[\-\w\d\.:]'
NAME = "([\\w:]#{NAMECHAR}*)"
NMTOKEN = "(?:#{NAMECHAR})+"
NMTOKENS = "#{NMTOKEN}(\\s+#{NMTOKEN})*"
REFERENCE = "(?:&#{NAME};|&#\\d+;|&#x[0-9a-fA-F]+;)"
REFERENCE_RE = /#{REFERENCE}/
DOCTYPE_START = /\A\s*<!DOCTYPE\s/um
DOCTYPE_PATTERN = /\s*<!DOCTYPE\s+(.*?)(\[|>)/um
ATTRIBUTE_PATTERN = /\s*(#{NAME_STR})\s*=\s*(["'])(.*?)\2/um
COMMENT_START = /\A<!--/u
COMMENT_PATTERN = /<!--(.*?)-->/um
CDATA_START = /\A<!\[CDATA\[/u
CDATA_END = /^\s*\]\s*>/um
CDATA_PATTERN = /<!\[CDATA\[(.*?)\]\]>/um
XMLDECL_START = /\A<\?xml\s/u;
XMLDECL_PATTERN = /<\?xml\s+(.*?)\?>*/um
INSTRUCTION_START = /\A<\?/u
INSTRUCTION_PATTERN = /<\?(.*?)(\s+.*?)?\?>/um
TAG_MATCH = /^<((?>#{NAME_STR}))\s*((?>\s+#{NAME_STR}\s*=\s*(["']).*?\3)*)\s*(\/)?>/um
CLOSE_MATCH = /^\s*<\/(#{NAME_STR})\s*>/um
VERSION = /\bversion\s*=\s*["'](.*?)['"]/um
ENCODING = /\bencoding=["'](.*?)['"]/um
STANDALONE = /\bstandalone=["'](.*?)['"]/um
ENTITY_START = /^\s*<!ENTITY/
IDENTITY = /^([!\*\w\-]+)(\s+#{NCNAME_STR})?(\s+["'].*?['"])?(\s+['"].*?["'])?/u
ELEMENTDECL_START = /^\s*<!ELEMENT/um
ELEMENTDECL_PATTERN = /^\s*(<!ELEMENT.*?)>/um
SYSTEMENTITY = /^\s*(%.*?;)\s*$/um
ENUMERATION = "\\(\\s*#{NMTOKEN}(?:\\s*\\|\\s*#{NMTOKEN})*\\s*\\)"
NOTATIONTYPE = "NOTATION\\s+\\(\\s*#{NAME}(?:\\s*\\|\\s*#{NAME})*\\s*\\)"
ENUMERATEDTYPE = "(?:(?:#{NOTATIONTYPE})|(?:#{ENUMERATION}))"
ATTTYPE = "(CDATA|ID|IDREF|IDREFS|ENTITY|ENTITIES|NMTOKEN|NMTOKENS|#{ENUMERATEDTYPE})"
ATTVALUE = "(?:\"((?:[^<&\"]|#{REFERENCE})*)\")|(?:'((?:[^<&']|#{REFERENCE})*)')"
DEFAULTDECL = "(#REQUIRED|#IMPLIED|(?:(#FIXED\\s+)?#{ATTVALUE}))"
ATTDEF = "\\s+#{NAME}\\s+#{ATTTYPE}\\s+#{DEFAULTDECL}"
ATTDEF_RE = /#{ATTDEF}/
ATTLISTDECL_START = /^\s*<!ATTLIST/um
ATTLISTDECL_PATTERN = /^\s*<!ATTLIST\s+#{NAME}(?:#{ATTDEF})*\s*>/um
NOTATIONDECL_START = /^\s*<!NOTATION/um
PUBLIC = /^\s*<!NOTATION\s+(\w[\-\w]*)\s+(PUBLIC)\s+((["']).*?\4)\s*>/um
SYSTEM = /^\s*<!NOTATION\s+(\w[\-\w]*)\s+(SYSTEM)\s+((["']).*?\4)\s*>/um
TEXT_PATTERN = /\A([^<]*)/um
# Entity constants
PUBIDCHAR = "\x20\x0D\x0Aa-zA-Z0-9\\-()+,./:=?;!*@$_%#"
SYSTEMLITERAL = %Q{((?:"[^"]*")|(?:'[^']*'))}
PUBIDLITERAL = %Q{("[#{PUBIDCHAR}']*"|'[#{PUBIDCHAR}]*')}
EXTERNALID = "(?:(?:(SYSTEM)\\s+#{SYSTEMLITERAL})|(?:(PUBLIC)\\s+#{PUBIDLITERAL}\\s+#{SYSTEMLITERAL}))"
NDATADECL = "\\s+NDATA\\s+#{NAME}"
PEREFERENCE = "%#{NAME};"
ENTITYVALUE = %Q{((?:"(?:[^%&"]|#{PEREFERENCE}|#{REFERENCE})*")|(?:'([^%&']|#{PEREFERENCE}|#{REFERENCE})*'))}
PEDEF = "(?:#{ENTITYVALUE}|#{EXTERNALID})"
ENTITYDEF = "(?:#{ENTITYVALUE}|(?:#{EXTERNALID}(#{NDATADECL})?))"
PEDECL = "<!ENTITY\\s+(%)\\s+#{NAME}\\s+#{PEDEF}\\s*>"
GEDECL = "<!ENTITY\\s+#{NAME}\\s+#{ENTITYDEF}\\s*>"
ENTITYDECL = /\s*(?:#{GEDECL})|(?:#{PEDECL})/um
EREFERENCE = /&(?!#{NAME};)/
DEFAULT_ENTITIES = {
'gt' => [/>/, '>', '>', />/],
'lt' => [/</, '<', '<', /</],
'quot' => [/"/, '"', '"', /"/],
"apos" => [/'/, "'", "'", /'/]
}
def initialize( source )
self.stream = source
end
def add_listener( listener )
if !defined?(@listeners) or !@listeners
@listeners = []
instance_eval <<-EOL
alias :_old_pull :pull
def pull
event = _old_pull
@listeners.each do |listener|
listener.receive event
end
event
end
EOL
end
@listeners << listener
end
attr_reader :source
def stream=( source )
if source.kind_of? String
@source = Source.new(source)
elsif source.kind_of? IO
@source = IOSource.new(source)
elsif source.kind_of? Source
@source = source
elsif defined? StringIO and source.kind_of? StringIO
@source = IOSource.new(source)
else
raise "#{source.class} is not a valid input stream. It must be \n"+
"either a String, IO, StringIO or Source."
end
@closed = nil
@document_status = nil
@tags = []
@stack = []
@entities = []
end
# Returns true if there are no more events
def empty?
#puts "@source.empty? = #{@source.empty?}"
#puts "@stack.empty? = #{@stack.empty?}"
return (@source.empty? and @stack.empty?)
end
# Returns true if there are more events. Synonymous with !empty?
def has_next?
return !(@source.empty? and @stack.empty?)
end
# Push an event back on the head of the stream. This method
# has (theoretically) infinite depth.
def unshift token
@stack.unshift(token)
end
# Peek at the +depth+ event in the stack. The first element on the stack
# is at depth 0. If +depth+ is -1, will parse to the end of the input
# stream and return the last event, which is always :end_document.
# Be aware that this causes the stream to be parsed up to the +depth+
# event, so you can effectively pre-parse the entire document (pull the
# entire thing into memory) using this method.
def peek depth=0
raise %Q[Illegal argument "#{depth}"] if depth < -1
temp = []
if depth == -1
temp.push(pull()) until empty?
else
while @stack.size+temp.size < depth+1
temp.push(pull())
end
end
@stack += temp if temp.size > 0
@stack[depth]
end
# Returns the next event. This is a +PullEvent+ object.
def pull
if @closed
x, @closed = @closed, nil
return [ :end_element, x ]
end
return [ :end_document ] if empty?
return @stack.shift if @stack.size > 0
@source.read if @source.buffer.size<2
if @document_status == nil
@source.consume( /^\s*/um )
word = @source.match( /(<[^>]*)>/um )
word = word[1] unless word.nil?
case word
when COMMENT_START
return [ :comment, @source.match( COMMENT_PATTERN, true )[1] ]
when XMLDECL_START
results = @source.match( XMLDECL_PATTERN, true )[1]
version = VERSION.match( results )
version = version[1] unless version.nil?
encoding = ENCODING.match(results)
encoding = encoding[1] unless encoding.nil?
@source.encoding = encoding
standalone = STANDALONE.match(results)
standalone = standalone[1] unless standalone.nil?
return [ :xmldecl, version, encoding, standalone]
when INSTRUCTION_START
return [ :processing_instruction, *@source.match(INSTRUCTION_PATTERN, true)[1,2] ]
when DOCTYPE_START
md = @source.match( DOCTYPE_PATTERN, true )
identity = md[1]
close = md[2]
identity =~ IDENTITY
name = $1
raise REXML::ParseException("DOCTYPE is missing a name") if name.nil?
pub_sys = $2.nil? ? nil : $2.strip
long_name = $3.nil? ? nil : $3.strip
uri = $4.nil? ? nil : $4.strip
args = [ :start_doctype, name, pub_sys, long_name, uri ]
if close == ">"
@document_status = :after_doctype
@source.read if @source.buffer.size<2
md = @source.match(/^\s*/um, true)
@stack << [ :end_doctype ]
else
@document_status = :in_doctype
end
return args
else
@document_status = :after_doctype
@source.read if @source.buffer.size<2
md = @source.match(/\s*/um, true)
end
end
if @document_status == :in_doctype
md = @source.match(/\s*(.*?>)/um)
case md[1]
when SYSTEMENTITY
match = @source.match( SYSTEMENTITY, true )[1]
return [ :externalentity, match ]
when ELEMENTDECL_START
return [ :elementdecl, @source.match( ELEMENTDECL_PATTERN, true )[1] ]
when ENTITY_START
match = @source.match( ENTITYDECL, true ).to_a.compact
match[0] = :entitydecl
ref = false
if match[1] == '%'
ref = true
match.delete_at 1
end
# Now we have to sort out what kind of entity reference this is
if match[2] == 'SYSTEM'
# External reference
match[3] = match[3][1..-2] # PUBID
match.delete_at(4) if match.size > 4 # Chop out NDATA decl
# match is [ :entity, name, SYSTEM, pubid(, ndata)? ]
elsif match[2] == 'PUBLIC'
# External reference
match[3] = match[3][1..-2] # PUBID
match[4] = match[4][1..-2] # HREF
# match is [ :entity, name, PUBLIC, pubid, href ]
else
match[2] = match[2][1..-2]
match.pop if match.size == 4
# match is [ :entity, name, value ]
end
match << '%' if ref
return match
when ATTLISTDECL_START
md = @source.match( ATTLISTDECL_PATTERN, true )
raise REXML::ParseException.new( "Bad ATTLIST declaration!", @source ) if md.nil?
element = md[1]
contents = md[0]
pairs = {}
values = md[0].scan( ATTDEF_RE )
values.each do |attdef|
unless attdef[3] == "#IMPLIED"
attdef.compact!
val = attdef[3]
val = attdef[4] if val == "#FIXED "
pairs[attdef[0]] = val
end
end
return [ :attlistdecl, element, pairs, contents ]
when NOTATIONDECL_START
md = nil
if @source.match( PUBLIC )
md = @source.match( PUBLIC, true )
elsif @source.match( SYSTEM )
md = @source.match( SYSTEM, true )
else
raise REXML::ParseException.new( "error parsing notation: no matching pattern", @source )
end
return [ :notationdecl, md[1], md[2], md[3] ]
when CDATA_END
@document_status = :after_doctype
@source.match( CDATA_END, true )
return [ :end_doctype ]
end
end
begin
if @source.buffer[0] == ?<
if @source.buffer[1] == ?/
last_tag = @tags.pop
#md = @source.match_to_consume( '>', CLOSE_MATCH)
md = @source.match( CLOSE_MATCH, true )
raise REXML::ParseException.new( "Missing end tag for "+
"'#{last_tag}' (got \"#{md[1]}\")",
@source) unless last_tag == md[1]
return [ :end_element, last_tag ]
elsif @source.buffer[1] == ?!
md = @source.match(/\A(\s*[^>]*>)/um)
#puts "SOURCE BUFFER = #{source.buffer}, #{source.buffer.size}"
raise REXML::ParseException.new("Malformed node", @source) unless md
if md[0][2] == ?-
md = @source.match( COMMENT_PATTERN, true )
return [ :comment, md[1] ] if md
else
md = @source.match( CDATA_PATTERN, true )
return [ :cdata, md[1] ] if md
end
raise REXML::ParseException.new( "Declarations can only occur "+
"in the doctype declaration.", @source)
elsif @source.buffer[1] == ??
md = @source.match( INSTRUCTION_PATTERN, true )
return [ :processing_instruction, md[1], md[2] ] if md
raise REXML::ParseException.new( "Bad instruction declaration",
@source)
else
# Get the next tag
md = @source.match(TAG_MATCH, true)
raise REXML::ParseException.new("malformed XML: missing tag start", @source) unless md
attrs = []
if md[2].size > 0
attrs = md[2].scan( ATTRIBUTE_PATTERN )
raise REXML::ParseException.new( "error parsing attributes: [#{attrs.join ', '}], excess = \"#$'\"", @source) if $' and $'.strip.size > 0
end
if md[4]
@closed = md[1]
else
@tags.push( md[1] )
end
attributes = {}
attrs.each { |a,b,c| attributes[a] = c }
return [ :start_element, md[1], attributes ]
end
else
md = @source.match( TEXT_PATTERN, true )
if md[0].length == 0
#puts "EMPTY = #{empty?}"
#puts "BUFFER = \"#{@source.buffer}\""
@source.match( /(\s+)/, true )
end
#return [ :text, "" ] if md[0].length == 0
# unnormalized = Text::unnormalize( md[1], self )
# return PullEvent.new( :text, md[1], unnormalized )
return [ :text, md[1] ]
end
rescue REXML::ParseException
raise
rescue Exception, NameError => error
raise REXML::ParseException.new( "Exception parsing",
@source, self, (error ? error : $!) )
end
return [ :dummy ]
end
def entity( reference, entities )
value = nil
value = entities[ reference ] if entities
if not value
value = DEFAULT_ENTITIES[ reference ]
value = value[2] if value
end
unnormalize( value, entities ) if value
end
# Escapes all possible entities
def normalize( input, entities=nil, entity_filter=nil )
copy = input.clone
# Doing it like this rather than in a loop improves the speed
copy.gsub!( EREFERENCE, '&' )
entities.each do |key, value|
copy.gsub!( value, "&#{key};" ) unless entity_filter and
entity_filter.include?(entity)
end if entities
copy.gsub!( EREFERENCE, '&' )
DEFAULT_ENTITIES.each do |key, value|
copy.gsub!( value[3], value[1] )
end
copy
end
# Unescapes all possible entities
def unnormalize( string, entities=nil, filter=nil )
rv = string.clone
rv.gsub!( /\r\n?/, "\n" )
matches = rv.scan( REFERENCE_RE )
return rv if matches.size == 0
rv.gsub!( /�*((?:\d+)|(?:x[a-fA-F0-9]+));/ ) {|m|
m=$1
m = "0#{m}" if m[0] == ?x
[Integer(m)].pack('U*')
}
matches.collect!{|x|x[0]}.compact!
if matches.size > 0
matches.each do |entity_reference|
unless filter and filter.include?(entity_reference)
entity_value = entity( entity_reference, entities )
if entity_value
re = /&#{entity_reference};/
rv.gsub!( re, entity_value )
end
end
end
matches.each do |entity_reference|
unless filter and filter.include?(entity_reference)
er = DEFAULT_ENTITIES[entity_reference]
rv.gsub!( er[0], er[2] ) if er
end
end
rv.gsub!( /&/, '&' )
end
rv
end
end
end
end
=begin
case event[0]
when :start_element
when :text
when :end_element
when :processing_instruction
when :cdata
when :comment
when :xmldecl
when :start_doctype
when :end_doctype
when :externalentity
when :elementdecl
when :entity
when :attlistdecl
when :notationdecl
when :end_doctype
end
=end