JezK
Edit File: baseparser.rb
require 'rexml/parseexception' require 'rexml/undefinednamespaceexception' require 'rexml/source' require 'set' 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 LETTER = '[:alpha:]' DIGIT = '[:digit:]' COMBININGCHAR = '' # TODO EXTENDER = '' # TODO NCNAME_STR= "[#{LETTER}_:][-[:alnum:]._:#{COMBININGCHAR}#{EXTENDER}]*" NAME_STR= "(?:(#{NCNAME_STR}):)?(#{NCNAME_STR})" UNAME_STR= "(?:#{NCNAME_STR}:)?#{NCNAME_STR}" NAMECHAR = '[\-\w\.:]' 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*(["'])(.*?)\4/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+#{UNAME_STR}\s*=\s*(["']).*?\5)*)\s*(\/)?>/um CLOSE_MATCH = /^\s*<\/(#{NAME_STR})\s*>/um VERSION = /\bversion\s*=\s*["'](.*?)['"]/um ENCODING = /\bencoding\s*=\s*["'](.*?)['"]/um STANDALONE = /\bstandalone\s*=\s*["'](.*?)['"]/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*$/um ENUMERATION = "\\(\\s*#{NMTOKEN}(?:\\s*\\|\\s*#{NMTOKEN})*\\s*\\)" NOTATIONTYPE = "NOTATION\\s+\\(\\s*#{NAME}(?:\\s*\\|\\s*#{NAME})*\\s*\\)" ENUMERATEDTYPE = "(?:(?:#{NOTATIONTYPE})|(?:#{ENUMERATION}))" ATTTYPE = "(CDATA|ID|IDREF|IDREFS|ENTITY|ENTITIES|NMTOKEN|NMTOKENS|#{ENUMERATEDTYPE})" ATTVALUE = "(?:\"((?:[^<&\"]|#{REFERENCE})*)\")|(?:'((?:[^<&']|#{REFERENCE})*)')" DEFAULTDECL = "(#REQUIRED|#IMPLIED|(?:(#FIXED\\s+)?#{ATTVALUE}))" ATTDEF = "\\s+#{NAME}\\s+#{ATTTYPE}\\s+#{DEFAULTDECL}" ATTDEF_RE = /#{ATTDEF}/ ATTLISTDECL_START = /^\s*<!ATTLIST/um ATTLISTDECL_PATTERN = /^\s*<!ATTLIST\s+#{NAME}(?:#{ATTDEF})*\s*>/um NOTATIONDECL_START = /^\s*<!NOTATION/um PUBLIC = /^\s*<!NOTATION\s+(\w[\-\w]*)\s+(PUBLIC)\s+(["'])(.*?)\3(?:\s+(["'])(.*?)\5)?\s*>/um SYSTEM = /^\s*<!NOTATION\s+(\w[\-\w]*)\s+(SYSTEM)\s+(["'])(.*?)\3\s*>/um TEXT_PATTERN = /\A([^<]*)/um # Entity constants PUBIDCHAR = "\x20\x0D\x0Aa-zA-Z0-9\\-()+,./:=?;!*@$_%#" 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" => [/'/, "'", "'", /'/] } ###################################################################### # These are patterns to identify common markup errors, to make the # error messages more informative. ###################################################################### MISSING_ATTRIBUTE_QUOTES = /^<#{NAME_STR}\s+#{NAME_STR}\s*=\s*[^"']/um def initialize( source ) self.stream = source @listeners = [] end def add_listener( listener ) @listeners << listener end attr_reader :source def stream=( source ) @source = SourceFactory.create_from( source ) @closed = nil @document_status = nil @tags = [] @stack = [] @entities = [] @nsstack = [] end def position if @source.respond_to? :position @source.position else # FIXME 0 end end # Returns true if there are no more events def 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 pull_event.tap do |event| @listeners.each do |listener| listener.receive event end end end def pull_event if @closed x, @closed = @closed, nil return [ :end_element, x ] end return [ :end_document ] if empty? return @stack.shift if @stack.size > 0 #STDERR.puts @source.encoding @source.read if @source.buffer.size<2 #STDERR.puts "BUFFER = #{@source.buffer.inspect}" if @document_status == nil #@source.consume( /^\s*/um ) word = @source.match( /^((?:\s+)|(?:<[^>]*>))/um ) word = word[1] unless word.nil? #STDERR.puts "WORD = #{word.inspect}" case word when COMMENT_START return [ :comment, @source.match( COMMENT_PATTERN, true )[1] ] when XMLDECL_START #STDERR.puts "XMLDECL" 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 ) @nsstack.unshift(curr_ns=Set.new) identity = md[1] close = md[2] identity =~ IDENTITY name = $1 raise REXML::ParseException.new("DOCTYPE is missing a name") if name.nil? pub_sys = $2.nil? ? nil : $2.strip long_name = $4.nil? ? nil : $4.strip uri = $6.nil? ? nil : $6.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 when /^\s+/ else @document_status = :after_doctype @source.read if @source.buffer.size<2 md = @source.match(/\s*/um, true) if @source.encoding == "UTF-8" @source.buffer.force_encoding(::Encoding::UTF_8) end 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 if attdef[0] =~ /^xmlns:(.*)/ @nsstack[0] << $1 end end end return [ :attlistdecl, element, pairs, contents ] when NOTATIONDECL_START md = nil if @source.match( PUBLIC ) md = @source.match( PUBLIC, true ) vals = [md[1],md[2],md[4],md[6]] elsif @source.match( SYSTEM ) md = @source.match( SYSTEM, true ) vals = [md[1],md[2],nil,md[4]] else raise REXML::ParseException.new( "error parsing notation: no matching pattern", @source ) end return [ :notationdecl, *vals ] when CDATA_END @document_status = :after_doctype @source.match( CDATA_END, true ) return [ :end_doctype ] end end begin if @source.buffer[0] == ?< if @source.buffer[1] == ?/ @nsstack.shift last_tag = @tags.pop #md = @source.match_to_consume( '>', CLOSE_MATCH) md = @source.match( CLOSE_MATCH, true ) raise REXML::ParseException.new( "Missing end tag for "+ "'#{last_tag}' (got \"#{md[1]}\")", @source) unless last_tag == md[1] return [ :end_element, last_tag ] elsif @source.buffer[1] == ?! md = @source.match(/\A(\s*[^>]*>)/um) #STDERR.puts "SOURCE BUFFER = #{source.buffer}, #{source.buffer.size}" raise REXML::ParseException.new("Malformed node", @source) unless md if md[0][2] == ?- md = @source.match( COMMENT_PATTERN, true ) case md[1] when /--/, /-$/ raise REXML::ParseException.new("Malformed comment", @source) end 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) unless md # Check for missing attribute quotes raise REXML::ParseException.new("missing attribute quote", @source) if @source.match(MISSING_ATTRIBUTE_QUOTES ) raise REXML::ParseException.new("malformed XML: missing tag start", @source) end attributes = {} prefixes = Set.new prefixes << md[2] if md[2] @nsstack.unshift(curr_ns=Set.new) if md[4].size > 0 attrs = md[4].scan( ATTRIBUTE_PATTERN ) raise REXML::ParseException.new( "error parsing attributes: [#{attrs.join ', '}], excess = \"#$'\"", @source) if $' and $'.strip.size > 0 attrs.each { |a,b,c,d,e| if b == "xmlns" if c == "xml" if e != "http://www.w3.org/XML/1998/namespace" msg = "The 'xml' prefix must not be bound to any other namespace "+ "(http://www.w3.org/TR/REC-xml-names/#ns-decl)" raise REXML::ParseException.new( msg, @source, self ) end elsif c == "xmlns" msg = "The 'xmlns' prefix must not be declared "+ "(http://www.w3.org/TR/REC-xml-names/#ns-decl)" raise REXML::ParseException.new( msg, @source, self) end curr_ns << c elsif b prefixes << b unless b == "xml" end if attributes.has_key? a msg = "Duplicate attribute #{a.inspect}" raise REXML::ParseException.new( msg, @source, self) end attributes[a] = e } end # Verify that all of the prefixes have been defined for prefix in prefixes unless @nsstack.find{|k| k.member?(prefix)} raise UndefinedNamespaceException.new(prefix,@source,self) end end if md[6] @closed = md[1] @nsstack.shift else @tags.push( md[1] ) end return [ :start_element, md[1], attributes ] end else md = @source.match( TEXT_PATTERN, true ) if md[0].length == 0 @source.match( /(\s+)/, true ) end #STDERR.puts "GOT #{md[1].inspect}" unless md[0].length == 0 #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::UndefinedNamespaceException raise rescue REXML::ParseException raise rescue Exception, NameError => error raise REXML::ParseException.new( "Exception parsing", @source, self, (error ? error : $!) ) end return [ :dummy ] end private :pull_event 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=$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 ) else er = DEFAULT_ENTITIES[entity_reference] rv.gsub!( er[0], er[2] ) if er end 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