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 /</ =~ source
end
# Attempt to convert rss to a URI, but just return it if
# there's a ::URI::Error
def to_uri(rss)
return rss if rss.is_a?(::URI::Generic)
begin
::URI.parse(rss)
rescue ::URI::Error
rss
end
end
end
class BaseParser
class << self
def raise_for_undefined_entity?
listener.raise_for_undefined_entity?
end
end
def initialize(rss)
@listener = self.class.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
@@accessor_bases = {}
@@registered_uris = {}
@@class_names = {}
# return the setter for the uri, tag_name pair, or nil.
def setter(uri, tag_name)
_getter = getter(uri, tag_name)
if _getter
"#{_getter}="
else
nil
end
end
def getter(uri, tag_name)
(@@accessor_bases[uri] || {})[tag_name]
end
# return the tag_names for setters associated with uri
def available_tags(uri)
(@@accessor_bases[uri] || {}).keys
end
# register uri against this name.
def register_uri(uri, name)
@@registered_uris[name] ||= {}
@@registered_uris[name][uri] = nil
end
# test if this uri is registered against this name
def uri_registered?(uri, name)
@@registered_uris[name].has_key?(uri)
end
# record class_name for the supplied uri and tag_name
def install_class_name(uri, tag_name, class_name)
@@class_names[uri] ||= {}
@@class_names[uri][tag_name] = class_name
end
# retrieve class_name for the supplied uri and tag_name
# If it doesn't exist, capitalize the tag_name
def class_name(uri, tag_name)
name = (@@class_names[uri] || {})[tag_name]
return name if name
tag_name = tag_name.gsub(/[_\-]([a-z]?)/) {$1.upcase}
tag_name[0, 1].upcase + tag_name[1..-1]
end
def install_get_text_element(uri, name, accessor_base)
install_accessor_base(uri, name, accessor_base)
def_get_text_element(uri, name, *get_file_and_line_from_caller(1))
end
def raise_for_undefined_entity?
true
end
private
# set the accessor for the uri, tag_name pair
def install_accessor_base(uri, tag_name, accessor_base)
@@accessor_bases[uri] ||= {}
@@accessor_bases[uri][tag_name] = accessor_base.chomp("=")
end
def def_get_text_element(uri, element_name, file, line)
register_uri(uri, element_name)
method_name = "start_#{element_name}"
unless private_method_defined?(method_name)
define_method(method_name) do |name, prefix, attrs, ns|
uri = _ns(ns, prefix)
if self.class.uri_registered?(uri, element_name)
start_get_text_element(name, prefix, ns, uri)
else
start_else_element(name, prefix, attrs, ns)
end
end
private(method_name)
end
end
end
end
module ListenerMixin
attr_reader :rss
attr_accessor :ignore_unknown_element
attr_accessor :do_validate
def initialize
@rss = nil
@ignore_unknown_element = true
@do_validate = true
@ns_stack = [{"xml" => :xml}]
@tag_stack = [[]]
@text_stack = ['']
@proc_stack = []
@last_element = nil
@version = @encoding = @standalone = nil
@xml_stylesheets = []
@xml_child_mode = false
@xml_element = nil
@last_xml_element = nil
end
# set instance vars for version, encoding, standalone
def xmldecl(version, encoding, standalone)
@version, @encoding, @standalone = version, encoding, standalone
end
def instruction(name, content)
if name == "xml-stylesheet"
params = parse_pi_content(content)
if params.has_key?("href")
@xml_stylesheets << XMLStyleSheet.new(params)
end
end
end
def tag_start(name, attributes)
@text_stack.push('')
ns = @ns_stack.last.dup
attrs = {}
attributes.each do |n, v|
if /\Axmlns(?:\z|:)/ =~ n
ns[$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 known_class?(current_class, 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(setup_next_element_in_unknown_element)
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
if Module.method(:const_defined?).arity == -1
def known_class?(target_class, class_name)
class_name and
(target_class.const_defined?(class_name, false) or
target_class.constants.include?(class_name.to_sym))
end
else
def known_class?(target_class, class_name)
class_name and
(target_class.const_defined?(class_name) or
target_class.constants.include?(class_name))
end
end
NAMESPLIT = /^(?:([\w:][-\w.]*):)?([\w:][-\w.]*)/
def split_name(name)
name =~ NAMESPLIT
[$1 || '', $2]
end
def check_ns(tag_name, prefix, ns, require_uri, ignore_unknown_element=nil)
if _ns(ns, prefix) == require_uri
true
else
if ignore_unknown_element.nil?
ignore_unknown_element = @ignore_unknown_element
end
if ignore_unknown_element
false
elsif @do_validate
raise NSError.new(tag_name, prefix, require_uri)
else
# Force bind required URI with prefix
@ns_stack.last[prefix] = require_uri
true
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 setter and @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)
if 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))
else
@proc_stack.push(setup_next_element_in_unknown_element)
end
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 = text.lstrip.unpack("m").first
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
def setup_next_element_in_unknown_element
current_element, @last_element = @last_element, nil
Proc.new {@last_element = current_element}
end
end
unless const_defined? :AVAILABLE_PARSER_LIBRARIES
# The list of all available libraries for parsing.
AVAILABLE_PARSER_LIBRARIES = [
["rss/xmlparser", :XMLParserParser],
["rss/xmlscanner", :XMLScanParser],
["rss/rexmlparser", :REXMLParser],
]
end
# The list of all available parsers, in constant form.
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