require "forwardable" require "open-uri" require "rss/rss" require "rss/xml" module RSS class NotWellFormedError < Error attr_reader :line, :element # Create a new NotWellFormedError for an error at +line+ # in +element+. If a block is given the return value of # the block ends up in the error message. def initialize(line=nil, element=nil) message = "This is not well formed XML" if element or line message << "\nerror occurred" message << " in #{element}" if element message << " at about #{line} line" if line end message << "\n#{yield}" if block_given? super(message) end end class XMLParserNotFound < Error def initialize super("available XML parser was not found in " << "#{AVAILABLE_PARSER_LIBRARIES.inspect}.") end end class NotValidXMLParser < Error def initialize(parser) super("#{parser} is not an available XML parser. " << "Available XML parser"<< (AVAILABLE_PARSERS.size > 1 ? "s are ": " is ") << "#{AVAILABLE_PARSERS.inspect}.") end end class NSError < InvalidRSSError attr_reader :tag, :prefix, :uri def initialize(tag, prefix, require_uri) @tag, @prefix, @uri = tag, prefix, require_uri super("prefix <#{prefix}> doesn't associate uri " << "<#{require_uri}> in tag <#{tag}>") end end class Parser extend Forwardable class << self @@default_parser = nil def default_parser @@default_parser || AVAILABLE_PARSERS.first end # Set @@default_parser to new_value if it is one of the # available parsers. Else raise NotValidXMLParser error. def default_parser=(new_value) if AVAILABLE_PARSERS.include?(new_value) @@default_parser = new_value else raise NotValidXMLParser.new(new_value) end end def parse(rss, do_validate=true, ignore_unknown_element=true, parser_class=default_parser) parser = new(rss, parser_class) parser.do_validate = do_validate parser.ignore_unknown_element = ignore_unknown_element parser.parse end end def_delegators(:@parser, :parse, :rss, :ignore_unknown_element, :ignore_unknown_element=, :do_validate, :do_validate=) def initialize(rss, parser_class=self.class.default_parser) @parser = parser_class.new(normalize_rss(rss)) end private # Try to get the XML associated with +rss+. # Return +rss+ if it already looks like XML, or treat it as a URI, # or a file to get the XML, def normalize_rss(rss) return rss if maybe_xml?(rss) uri = to_uri(rss) if uri.respond_to?(:read) uri.read elsif !rss.tainted? and File.readable?(rss) File.open(rss) {|f| f.read} else rss end end # maybe_xml? tests if source is a string that looks like XML. def maybe_xml?(source) source.is_a?(String) and / :xml}] @tag_stack = [[]] @text_stack = [''] @proc_stack = [] @last_element = nil @version = @encoding = @standalone = nil @xml_stylesheets = [] @xml_child_mode = false @xml_element = nil @last_xml_element = nil end # set instance vars for version, encoding, standalone def xmldecl(version, encoding, standalone) @version, @encoding, @standalone = version, encoding, standalone end def instruction(name, content) if name == "xml-stylesheet" params = parse_pi_content(content) if params.has_key?("href") @xml_stylesheets << XMLStyleSheet.new(params) end end end def tag_start(name, attributes) @text_stack.push('') ns = @ns_stack.last.dup attrs = {} attributes.each do |n, v| if /\Axmlns(?:\z|:)/ =~ n ns[$POSTMATCH] = v else attrs[n] = v end end @ns_stack.push(ns) prefix, local = split_name(name) @tag_stack.last.push([_ns(ns, prefix), local]) @tag_stack.push([]) if @xml_child_mode previous = @last_xml_element element_attrs = attributes.dup unless previous ns.each do |ns_prefix, value| next if ns_prefix == "xml" key = ns_prefix.empty? ? "xmlns" : "xmlns:#{ns_prefix}" element_attrs[key] ||= value end end next_element = XML::Element.new(local, prefix.empty? ? nil : prefix, _ns(ns, prefix), element_attrs) previous << next_element if previous @last_xml_element = next_element pr = Proc.new do |text, tags| if previous @last_xml_element = previous else @xml_element = @last_xml_element @last_xml_element = nil end end @proc_stack.push(pr) else if @rss.nil? and respond_to?("initial_start_#{local}", true) __send__("initial_start_#{local}", local, prefix, attrs, ns.dup) elsif respond_to?("start_#{local}", true) __send__("start_#{local}", local, prefix, attrs, ns.dup) else start_else_element(local, prefix, attrs, ns.dup) end end end def tag_end(name) if DEBUG p "end tag #{name}" p @tag_stack end text = @text_stack.pop tags = @tag_stack.pop pr = @proc_stack.pop pr.call(text, tags) unless pr.nil? @ns_stack.pop end def text(data) if @xml_child_mode @last_xml_element << data if @last_xml_element else @text_stack.last << data end end private def _ns(ns, prefix) ns.fetch(prefix, "") end CONTENT_PATTERN = /\s*([^=]+)=(["'])([^\2]+?)\2/ # Extract the first name="value" pair from content. # Works with single quotes according to the constant # CONTENT_PATTERN. Return a Hash. def parse_pi_content(content) params = {} content.scan(CONTENT_PATTERN) do |name, quote, value| params[name] = value end params end def start_else_element(local, prefix, attrs, ns) class_name = self.class.class_name(_ns(ns, prefix), local) current_class = @last_element.class if class_name and (current_class.const_defined?(class_name) or current_class.constants.include?(class_name)) next_class = current_class.const_get(class_name) start_have_something_element(local, prefix, attrs, ns, next_class) else if !@do_validate or @ignore_unknown_element @proc_stack.push(nil) else parent = "ROOT ELEMENT???" if current_class.tag_name parent = current_class.tag_name end raise NotExpectedTagError.new(local, _ns(ns, prefix), parent) end end end NAMESPLIT = /^(?:([\w:][-\w\d.]*):)?([\w:][-\w\d.]*)/ def split_name(name) name =~ NAMESPLIT [$1 || '', $2] end def check_ns(tag_name, prefix, ns, require_uri) unless _ns(ns, prefix) == require_uri if @do_validate raise NSError.new(tag_name, prefix, require_uri) else # Force bind required URI with prefix @ns_stack.last[prefix] = require_uri end end end def start_get_text_element(tag_name, prefix, ns, required_uri) pr = Proc.new do |text, tags| setter = self.class.setter(required_uri, tag_name) if @last_element.respond_to?(setter) if @do_validate getter = self.class.getter(required_uri, tag_name) if @last_element.__send__(getter) raise TooMuchTagError.new(tag_name, @last_element.tag_name) end end @last_element.__send__(setter, text.to_s) else if @do_validate and !@ignore_unknown_element raise NotExpectedTagError.new(tag_name, _ns(ns, prefix), @last_element.tag_name) end end end @proc_stack.push(pr) end def start_have_something_element(tag_name, prefix, attrs, ns, klass) check_ns(tag_name, prefix, ns, klass.required_uri) attributes = collect_attributes(tag_name, prefix, attrs, ns, klass) @proc_stack.push(setup_next_element(tag_name, klass, attributes)) end def collect_attributes(tag_name, prefix, attrs, ns, klass) attributes = {} klass.get_attributes.each do |a_name, a_uri, required, element_name| if a_uri.is_a?(String) or !a_uri.respond_to?(:include?) a_uri = [a_uri] end unless a_uri == [""] for prefix, uri in ns if a_uri.include?(uri) val = attrs["#{prefix}:#{a_name}"] break if val end end end if val.nil? and a_uri.include?("") val = attrs[a_name] end if @do_validate and required and val.nil? unless a_uri.include?("") for prefix, uri in ns if a_uri.include?(uri) a_name = "#{prefix}:#{a_name}" end end end raise MissingAttributeError.new(tag_name, a_name) end attributes[a_name] = val end attributes end def setup_next_element(tag_name, klass, attributes) previous = @last_element next_element = klass.new(@do_validate, attributes) previous.set_next_element(tag_name, next_element) @last_element = next_element @last_element.parent = previous if klass.need_parent? @xml_child_mode = @last_element.have_xml_content? Proc.new do |text, tags| p(@last_element.class) if DEBUG if @xml_child_mode @last_element.content = @xml_element.to_s xml_setter = @last_element.class.xml_setter @last_element.__send__(xml_setter, @xml_element) @xml_element = nil @xml_child_mode = false else if klass.have_content? if @last_element.need_base64_encode? text = Base64.decode64(text.lstrip) end @last_element.content = text end end if @do_validate @last_element.validate_for_stream(tags, @ignore_unknown_element) end @last_element = previous end end end unless const_defined? :AVAILABLE_PARSER_LIBRARIES AVAILABLE_PARSER_LIBRARIES = [ ["rss/xmlparser", :XMLParserParser], ["rss/xmlscanner", :XMLScanParser], ["rss/rexmlparser", :REXMLParser], ] end AVAILABLE_PARSERS = [] AVAILABLE_PARSER_LIBRARIES.each do |lib, parser| begin require lib AVAILABLE_PARSERS.push(const_get(parser)) rescue LoadError end end if AVAILABLE_PARSERS.empty? raise XMLParserNotFound end end