diff options
Diffstat (limited to 'lib/rss/parser.rb')
-rw-r--r-- | lib/rss/parser.rb | 380 |
1 files changed, 380 insertions, 0 deletions
diff --git a/lib/rss/parser.rb b/lib/rss/parser.rb new file mode 100644 index 0000000000..e1c61f46ae --- /dev/null +++ b/lib/rss/parser.rb @@ -0,0 +1,380 @@ +require "forwardable" + +require "rss/rss" + +module RSS + + class NotWellFormedError < Error + attr_reader :line, :element + 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 does not found in " << + "#{AVAILABLE_PARSER_LIBRARIES.inspect}.") + end + end + + class NotValidXMLParser < Error + def initialize(parser) + super("#{parser} is not available XML parser. " << + "available XML parser 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 + + 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(rss) + end + end + + class BaseParser + + def initialize(rss) + @listener = listener.new + @rss = rss + end + + def rss + @listener.rss + end + + def ignore_unknown_element + @listener.ignore_unknown_element + end + + def ignore_unknown_element=(new_value) + @listener.ignore_unknown_element = new_value + end + + def do_validate + @listener.do_validate + end + + def do_validate=(new_value) + @listener.do_validate = new_value + end + + def parse + if @listener.rss.nil? + _parse + end + @listener.rss + end + + end + + class BaseListener + + extend Utils + + class << self + + @@setter = {} + def install_setter(uri, tag_name, setter) + @@setter[uri] = {} unless @@setter.has_key?(uri) + @@setter[uri][tag_name] = setter + end + + def setter(uri, tag_name) + begin + @@setter[uri][tag_name] + rescue NameError + nil + end + end + + def available_tags(uri) + begin + @@setter[uri].keys + rescue NameError + [] + end + end + + def install_get_text_element(name, uri, setter) + install_setter(uri, name, setter) + def_get_text_element(name, *get_file_and_line_from_caller(1)) + end + + private + + def def_get_text_element(name, file, line) + unless private_instance_methods(false).include?("start_#{name}") + module_eval(<<-EOT, file, line) + def start_#{name}(name, prefix, attrs, ns) + uri = ns[prefix] + if @do_validate + tags = self.class.available_tags(uri) + unless tags.include?(name) + raise UnknownTagError.new(name, uri) + end + end + start_get_text_element(name, prefix, ns, uri) + end + EOT + end + send("private", "start_#{name}") + end + + end + + end + + module ListenerMixin + + attr_reader :rss + + attr_accessor :ignore_unknown_element + attr_accessor :do_validate + + def initialize + @rss = nil + @ignore_unknown_element = true + @do_validate = true + @ns_stack = [{}] + @tag_stack = [[]] + @text_stack = [''] + @proc_stack = [] + @last_element = nil + @version = @encoding = @standalone = nil + @xml_stylesheets = [] + end + + 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 n =~ /\Axmlns:?/ + ns[$POSTMATCH] = v + else + attrs[n] = v + end + end + @ns_stack.push(ns) + + prefix, local = split_name(name) + @tag_stack.last.push([ns[prefix], local]) + @tag_stack.push([]) + if respond_to?("start_#{local}", true) + send("start_#{local}", local, prefix, attrs, ns.dup) + else + start_else_element(local, prefix, attrs, ns.dup) + 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? + end + + def text(data) + @text_stack.last << data + end + + private + + CONTENT_PATTERN = /\s*([^=]+)=(["'])([^\2]+?)\2/ + 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 = local[0,1].upcase << local[1..-1] + current_class = @last_element.class +# begin + if current_class.constants.include?(class_name) + next_class = current_class.const_get(class_name) + start_have_something_element(local, prefix, attrs, ns, next_class) +# rescue NameError + else + if @ignore_unknown_element + @proc_stack.push(nil) + else + parent = "ROOT ELEMENT???" + if current_class.const_defined?("TAG_NAME") + parent = current_class.const_get("TAG_NAME") + end + raise NotExceptedTagError.new(local, 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) + if @do_validate + if ns[prefix] == require_uri + #ns.delete(prefix) + else + raise NSError.new(tag_name, prefix, require_uri) + end + end + end + + def start_get_text_element(tag_name, prefix, ns, required_uri) + @proc_stack.push Proc.new {|text, tags| + setter = self.class.setter(required_uri, tag_name) + setter ||= "#{tag_name}=" + if @last_element.respond_to?(setter) + @last_element.send(setter, text.to_s) + else + if @do_validate and not @ignore_unknown_element + raise NotExceptedTagError.new(tag_name, @last_element.tag_name) + end + end + } + end + + def start_have_something_element(tag_name, prefix, attrs, ns, klass) + + check_ns(tag_name, prefix, ns, klass.required_uri) + + args = [] + + klass.get_attributes.each do |a_name, a_uri, required| + + if a_uri.is_a?(String) or !a_uri.respond_to?(:include?) + a_uri = [a_uri] + end + unless a_uri == [nil] + 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?(nil) + val = attrs[a_name] + end + + if @do_validate and required and val.nil? + raise MissingAttributeError.new(tag_name, a_name) + end + + args << val + end + + previous = @last_element + next_element = klass.send(:new, *args) + next_element.do_validate = @do_validate + setter = "" + setter << "#{klass.required_prefix}_" if klass.required_prefix + setter << "#{tag_name}=" + @last_element.send(setter, next_element) + @last_element = next_element + @proc_stack.push Proc.new { |text, tags| + p(@last_element.class) if DEBUG + @last_element.content = text if klass.have_content? + @last_element.validate_for_stream(tags) if @do_validate + @last_element = previous + } + 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 |