JezK
Edit File: sax2parser.rb
require 'rexml/parsers/baseparser' require 'rexml/parseexception' require 'rexml/namespace' require 'rexml/text' module REXML module Parsers # SAX2Parser class SAX2Parser def initialize source @parser = BaseParser.new(source) @listeners = [] @procs = [] @namespace_stack = [] @has_listeners = false @tag_stack = [] @entities = {} end def source @parser.source end def add_listener( listener ) @parser.add_listener( listener ) end # Listen arguments: # # Symbol, Array, Block # Listen to Symbol events on Array elements # Symbol, Block # Listen to Symbol events # Array, Listener # Listen to all events on Array elements # Array, Block # Listen to :start_element events on Array elements # Listener # Listen to All events # # Symbol can be one of: :start_element, :end_element, # :start_prefix_mapping, :end_prefix_mapping, :characters, # :processing_instruction, :doctype, :attlistdecl, :elementdecl, # :entitydecl, :notationdecl, :cdata, :xmldecl, :comment # # There is an additional symbol that can be listened for: :progress. # This will be called for every event generated, passing in the current # stream position. # # Array contains regular expressions or strings which will be matched # against fully qualified element names. # # Listener must implement the methods in SAX2Listener # # Block will be passed the same arguments as a SAX2Listener method would # be, where the method name is the same as the matched Symbol. # See the SAX2Listener for more information. def listen( *args, &blok ) if args[0].kind_of? Symbol if args.size == 2 args[1].each { |match| @procs << [args[0], match, blok] } else add( [args[0], nil, blok] ) end elsif args[0].kind_of? Array if args.size == 2 args[0].each { |match| add( [nil, match, args[1]] ) } else args[0].each { |match| add( [ :start_element, match, blok ] ) } end else add([nil, nil, args[0]]) end end def deafen( listener=nil, &blok ) if listener @listeners.delete_if {|item| item[-1] == listener } @has_listeners = false if @listeners.size == 0 else @procs.delete_if {|item| item[-1] == blok } end end def parse @procs.each { |sym,match,block| block.call if sym == :start_document } @listeners.each { |sym,match,block| block.start_document if sym == :start_document or sym.nil? } context = [] while true event = @parser.pull case event[0] when :end_document handle( :end_document ) break when :start_doctype handle( :doctype, *event[1..-1]) when :end_doctype context = context[1] when :start_element @tag_stack.push(event[1]) # find the observers for namespaces procs = get_procs( :start_prefix_mapping, event[1] ) listeners = get_listeners( :start_prefix_mapping, event[1] ) if procs or listeners # break out the namespace declarations # The attributes live in event[2] event[2].each {|n, v| event[2][n] = @parser.normalize(v)} nsdecl = event[2].find_all { |n, value| n =~ /^xmlns(:|$)/ } nsdecl.collect! { |n, value| [ n[6..-1], value ] } @namespace_stack.push({}) nsdecl.each do |n,v| @namespace_stack[-1][n] = v # notify observers of namespaces procs.each { |ob| ob.call( n, v ) } if procs listeners.each { |ob| ob.start_prefix_mapping(n, v) } if listeners end end event[1] =~ Namespace::NAMESPLIT prefix = $1 local = $2 uri = get_namespace(prefix) # find the observers for start_element procs = get_procs( :start_element, event[1] ) listeners = get_listeners( :start_element, event[1] ) # notify observers procs.each { |ob| ob.call( uri, local, event[1], event[2] ) } if procs listeners.each { |ob| ob.start_element( uri, local, event[1], event[2] ) } if listeners when :end_element @tag_stack.pop event[1] =~ Namespace::NAMESPLIT prefix = $1 local = $2 uri = get_namespace(prefix) # find the observers for start_element procs = get_procs( :end_element, event[1] ) listeners = get_listeners( :end_element, event[1] ) # notify observers procs.each { |ob| ob.call( uri, local, event[1] ) } if procs listeners.each { |ob| ob.end_element( uri, local, event[1] ) } if listeners namespace_mapping = @namespace_stack.pop # find the observers for namespaces procs = get_procs( :end_prefix_mapping, event[1] ) listeners = get_listeners( :end_prefix_mapping, event[1] ) if procs or listeners namespace_mapping.each do |ns_prefix, ns_uri| # notify observers of namespaces procs.each { |ob| ob.call( ns_prefix ) } if procs listeners.each { |ob| ob.end_prefix_mapping(ns_prefix) } if listeners end end when :text #normalized = @parser.normalize( event[1] ) #handle( :characters, normalized ) copy = event[1].clone esub = proc { |match| if @entities.has_key?($1) @entities[$1].gsub(Text::REFERENCE, &esub) else match end } copy.gsub!( Text::REFERENCE, &esub ) copy.gsub!( Text::NUMERICENTITY ) {|m| m=$1 m = "0#{m}" if m[0] == ?x [Integer(m)].pack('U*') } handle( :characters, copy ) when :entitydecl @entities[ event[1] ] = event[2] if event.size == 3 handle( *event ) when :processing_instruction, :comment, :attlistdecl, :elementdecl, :cdata, :notationdecl, :xmldecl handle( *event ) end handle( :progress, @parser.position ) end end private def handle( symbol, *arguments ) tag = @tag_stack[-1] procs = get_procs( symbol, tag ) listeners = get_listeners( symbol, tag ) # notify observers procs.each { |ob| ob.call( *arguments ) } if procs listeners.each { |l| l.send( symbol.to_s, *arguments ) } if listeners end # The following methods are duplicates, but it is faster than using # a helper def get_procs( symbol, name ) return nil if @procs.size == 0 @procs.find_all do |sym, match, block| #puts sym.inspect+"=="+symbol.inspect+ "\t"+match.inspect+"=="+name.inspect+ "\t"+( (sym.nil? or symbol == sym) and ((name.nil? and match.nil?) or match.nil? or ( (name == match) or (match.kind_of? Regexp and name =~ match)))).to_s ( (sym.nil? or symbol == sym) and ((name.nil? and match.nil?) or match.nil? or ( (name == match) or (match.kind_of? Regexp and name =~ match) ) ) ) end.collect{|x| x[-1]} end def get_listeners( symbol, name ) return nil if @listeners.size == 0 @listeners.find_all do |sym, match, block| ( (sym.nil? or symbol == sym) and ((name.nil? and match.nil?) or match.nil? or ( (name == match) or (match.kind_of? Regexp and name =~ match) ) ) ) end.collect{|x| x[-1]} end def add( pair ) if pair[-1].respond_to? :call @procs << pair unless @procs.include? pair else @listeners << pair unless @listeners.include? pair @has_listeners = true end end def get_namespace( prefix ) uris = (@namespace_stack.find_all { |ns| not ns[prefix].nil? }) || (@namespace_stack.find { |ns| not ns[nil].nil? }) uris[-1][prefix] unless uris.nil? or 0 == uris.size end end end end