/
feedparser.rb
385 lines (351 loc) · 11.7 KB
/
feedparser.rb
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require 'rexml/document'
require 'time'
require 'feedparser/textconverters'
require 'feedparser/rexml_patch'
require 'feedparser/text-output'
require 'base64'
require 'magic'
module FeedParser
VERSION = "0.7"
class UnknownFeedTypeException < RuntimeError
end
def self.recode(str)
encoding = nil
begin
encoding = Magic.guess_string_mime_encoding(str)
rescue Magic::Exception
# this happens when magic does not find any content at all, e.g. with
# strings that contain only whitespace. In these case it *should* be safe
# to assume UTF-8
encoding = Encoding::UTF_8
end
if encoding == 'unknown-8bit'
# find first substring with a valid encoding that is not us-ascii
length = 1 # has to start at 1, magic requires at least 2 bytes
while length < str.length && ['us-ascii', 'unknown-8bit'].include?(encoding)
encoding = Magic.guess_string_mime_encoding(str[0..length])
length = length + 1
end
# need to remove iso-8859-1 control characters
if encoding == 'iso-8859-1'
str = str.bytes.select { |c| c < 128 || c > 159 }.map(&:chr).join
end
end
str.force_encoding(encoding)
str = str.chars.select { |c| c.valid_encoding? }.join
str.encode('UTF-8')
end
# an RSS/Atom feed
class Feed
attr_reader :type, :title, :link, :description, :creator, :encoding, :items
# REXML::Element for this feed.
attr_reader :xml
# parse str to build a Feed
def initialize(str = nil)
parse(str) if str
end
# Determines all the fields using a string containing an
# XML document
def parse(str)
str = FeedParser.recode(str)
# Dirty hack: some feeds contain the & char. It must be changed to &
str.gsub!(/&(\s+)/, '&\1')
doc = REXML::Document.new(str)
@xml = doc.root
# get feed info
@encoding = doc.encoding
@title,@link,@description,@creator = nil
@title = ""
@items = []
if doc.root.elements['channel'] || doc.root.elements['rss:channel']
@type = "rss"
# We have a RSS feed!
# Title
if (e = doc.root.elements['channel/title'] ||
doc.root.elements['rss:channel/rss:title']) && e.text
@title = e.text.unescape_html.toUTF8(@encoding).rmWhiteSpace!
end
# Link
if (e = doc.root.elements['channel/link'] ||
doc.root.elements['rss:channel/rss:link']) && e.text
@link = e.text.rmWhiteSpace!
end
# Description
if (e = doc.root.elements['channel/description'] ||
doc.root.elements['rss:channel/rss:description']) && e.text
@description = e.text.toUTF8(@encoding).rmWhiteSpace!
end
# Creator
if ((e = doc.root.elements['channel/dc:creator']) && e.text) ||
((e = doc.root.elements['channel/author'] ||
doc.root.elements['rss:channel/rss:author']) && e.text)
@creator = e.text.unescape_html.toUTF8(@encoding).rmWhiteSpace!
end
# Items
if doc.root.elements['channel/item']
query = 'channel/item'
elsif doc.root.elements['item']
query = 'item'
elsif doc.root.elements['rss:channel/rss:item']
query = 'rss:channel/rss:item'
else
query = 'rss:item'
end
doc.root.each_element(query) { |e| @items << RSSItem::new(e, self) }
elsif doc.root.elements['/feed']
# We have an ATOM feed!
@type = "atom"
# Title
if (e = doc.root.elements['/feed/title']) && e.text
@title = e.text.unescape_html.toUTF8(@encoding).rmWhiteSpace!
end
# Link
doc.root.each_element('/feed/link') do |e|
if e.attribute('type') and (
e.attribute('type').value == 'text/html' or
e.attribute('type').value == 'application/xhtml' or
e.attribute('type').value == 'application/xhtml+xml')
if (h = e.attribute('href')) && h
@link = h.value.rmWhiteSpace!
end
end
end
# Description
if e = doc.root.elements['/feed/info']
e = e.elements['div'] || e
@description = e.to_s.toUTF8(@encoding).rmWhiteSpace!
end
# Items
doc.root.each_element('/feed/entry') do |e|
@items << AtomItem::new(e, self)
end
else
raise UnknownFeedTypeException::new
end
end
def to_s(localtime = true)
s = ''
s += "Type: #{@type}\n"
s += "Encoding: #{@encoding}\n"
s += "Title: #{@title}\n"
s += "Link: #{@link}\n"
s += "Description: #{@description}\n"
s += "Creator: #{@creator}\n"
s += "\n"
@items.each { |i| s += i.to_s(localtime) }
s
end
end
# an Item from a feed
class FeedItem
attr_accessor :title, :link, :content, :date, :creators, :subject,
:cacheditem, :links
# The item's categories/tags. An array of strings.
attr_accessor :categories
# The item's enclosures childs. An array of (url, length, type) triplets.
attr_accessor :enclosures
attr_reader :feed
# REXML::Element for this item
attr_reader :xml
def initialize(item = nil, feed = nil)
@xml = item
@feed = feed
@title, @link, @content, @date, @subject = nil
@links = []
@creators = []
@categories = []
@enclosures = []
@title = ""
parse(item) if item
end
def parse(item)
raise "parse() should be implemented by subclasses!"
end
def creator
case @creators.length
when 0
return nil
when 1
return creators[0]
else
return creators[0...-1].join(", ")+" and "+creators[-1]
end
end
def to_s(localtime = true)
s = "--------------------------------\n" +
"Title: #{@title}\nLink: #{@link}\n"
if localtime or @date.nil?
s += "Date: #{@date.to_s}\n"
else
s += "Date: #{@date.getutc.to_s}\n"
end
s += "Creator: #{creator}\n" +
"Subject: #{@subject}\n"
if defined?(@categories) and @categories.length > 0
s += "Filed under: " + @categories.join(', ') + "\n"
end
s += "Content:\n#{content}\n"
if defined?(@enclosures) and @enclosures.length > 0
s2 = "Enclosures:\n"
@enclosures.each do |e|
s2 += e.join(' ') + "\n"
end
s += s2
end
return s
end
end
class RSSItem < FeedItem
def parse(item)
# Title. If no title, use the pubDate as fallback.
if ((e = item.elements['title'] || item.elements['rss:title']) &&
e.text) ||
((e = item.elements['pubDate'] || item.elements['rss:pubDate']) &&
e.text)
@title = e.text.unescape_html.toUTF8(@feed.encoding).html2text.rmWhiteSpace!
end
# Link
if ((e = item.elements['link'] || item.elements['rss:link']) && e.text)||
(e = item.elements['guid'] || item.elements['rss:guid'] and
not (e.attribute('isPermaLink') and
e.attribute('isPermaLink').value == 'false'))
@link = e.text.rmWhiteSpace!
end
# Content
if (e = item.elements['content:encoded']) ||
(e = item.elements['description'] || item.elements['rss:description'])
@content = FeedParser::getcontent(e, @feed)
end
# Date
if e = item.elements['dc:date'] || item.elements['pubDate'] ||
item.elements['rss:pubDate']
begin
@date = Time::xmlschema(e.text)
rescue
begin
@date = Time::rfc2822(e.text)
rescue
begin
@date = Time::parse(e.text)
rescue
@date = nil
end
end
end
end
# Creator
if (e = item.elements['dc:creator'] || item.elements['author'] ||
item.elements['rss:author']) && e.text
@creators << e.text.unescape_html.toUTF8(@feed.encoding).rmWhiteSpace!
end
@creators << @feed.creator if @creators.empty? and @feed.creator
# Subject
if (e = item.elements['dc:subject']) && e.text
@subject = e.text.unescape_html.toUTF8(@feed.encoding).rmWhiteSpace!
end
# Categories
cat_elts = []
item.each_element('dc:category') { |e| cat_elts << e if e.text }
item.each_element('category') { |e| cat_elts << e if e.text }
item.each_element('rss:category') { |e| cat_elts << e if e.text }
cat_elts.each do |e|
@categories << e.text.unescape_html.toUTF8(@feed.encoding).rmWhiteSpace!
end
# Enclosures
item.each_element('enclosure') do |e|
url = e.attribute('url').value if e.attribute('url')
length = e.attribute('length').value if e.attribute('length')
type = e.attribute('type').value if e.attribute('type')
@enclosures << [ url, length, type ] if url
end
end
end
class AtomItem < FeedItem
def parse(item)
# Title
if (e = item.elements['title']) && e.text
@title = e.text.unescape_html.toUTF8(@feed.encoding).html2text.rmWhiteSpace!
end
# Link
item.each_element('link') do |e|
if (h = e.attribute('href')) && h.value
@link = h.value
if e.attribute('type')
@links << {:href => h.value, :type => e.attribute('type').value}
else
@links << {:href => h.value, :type => ''}
end
end
end
# Content
if e = item.elements['content'] || item.elements['summary']
if (e.attribute('mode') and e.attribute('mode').value == 'escaped') &&
e.text
@content = e.text.toUTF8(@feed.encoding).rmWhiteSpace!
else
@content = FeedParser::getcontent(e, @feed)
end
end
# Date
if (e = item.elements['issued'] || e = item.elements['created'] || e = item.elements['updated'] || e = item.elements['published']) && e.text
begin
@date = Time::xmlschema(e.text)
rescue
begin
@date = Time::rfc2822(e.text)
rescue
begin
@date = Time::parse(e.text)
rescue
@date = nil
end
end
end
end
# Creator
item.each_element('author/name') do |e|
if e.text
@creators << e.text.unescape_html.toUTF8(@feed.encoding).rmWhiteSpace!
end
end
@creators << @feed.creator if @creators.empty? and @feed.creator
# Categories
item.each_element('category') do |e|
if (h = e.attribute('term')) && h.value
# Use human-readable label if it is provided
if (l = e.attribute('label')) && l.value
cat = l.value
else
cat = h.value
end
@categories << cat.unescape_html.toUTF8(@feed.encoding).rmWhiteSpace!
end
end
end
end
def FeedParser::getcontent(e, feed = nil)
encoding = feed ? feed.encoding : 'utf-8'
children = e.children.reject do |i|
i.class == REXML::Text and i.to_s.chomp == ''
end
if children.length > 1
s = ''
children.each do |c|
s += c.to_s if c.class != REXML::Comment
end
return s.toUTF8(encoding).rmWhiteSpace!.text2html(feed)
elsif children.length == 1
c = children[0]
if c.class == REXML::Text
return e.text.toUTF8(encoding).rmWhiteSpace!.text2html(feed)
elsif c.class == REXML::CData
return c.to_s.toUTF8(encoding).rmWhiteSpace!.text2html(feed)
elsif c.class == REXML::Element
# only one element. recurse.
return getcontent(c, feed)
elsif c.text
return c.text.toUTF8(encoding).text2html(feed)
end
end
end
end