require_dependency 'nokogiri' require_dependency 'url_helper' class TopicEmbed < ActiveRecord::Base include Trashable belongs_to :topic belongs_to :post validates_presence_of :embed_url validates_uniqueness_of :embed_url before_validation(on: :create) do unless (topic_embed = TopicEmbed.with_deleted.where('deleted_at IS NOT NULL AND embed_url = ?', embed_url).first).nil? topic_embed.destroy! end end class FetchResponse attr_accessor :title, :body, :author end def self.normalize_url(url) url.downcase.sub(/\/$/, '').sub(/\-+/, '-').strip end def self.imported_from_html(url) "\n
\n#{I18n.t('embed.imported_from', link: "#{url}")}\n" end # Import an article from a source (RSS/Atom/Other) def self.import(user, url, title, contents) return unless url =~ /^https?\:\/\// if SiteSetting.embed_truncate contents = first_paragraph_from(contents) end contents ||= '' contents << imported_from_html(url) url = normalize_url(url) embed = TopicEmbed.find_by("lower(embed_url) = ?", url) content_sha1 = Digest::SHA1.hexdigest(contents) post = nil # If there is no embed, create a topic, post and the embed. if embed.blank? Topic.transaction do eh = EmbeddableHost.record_for_url(url) cook_method = if SiteSetting.embed_support_markdown Post.cook_methods[:regular] else Post.cook_methods[:raw_html] end creator = PostCreator.new(user, title: title, raw: absolutize_urls(url, contents), skip_validations: true, cook_method: cook_method, category: eh.try(:category_id)) post = creator.create if post.present? TopicEmbed.create!(topic_id: post.topic_id, embed_url: url, content_sha1: content_sha1, post_id: post.id) end end else absolutize_urls(url, contents) post = embed.post # Update the topic if it changed if post && post.topic && content_sha1 != embed.content_sha1 post_revision_args = { raw: absolutize_urls(url, contents), user_id: user.id, title: title, } post.revise(user, post_revision_args, skip_validations: true, bypass_rate_limiter: true) embed.update_column(:content_sha1, content_sha1) end end post end def self.find_remote(url) require 'ruby-readability' url = UrlHelper.escape_uri(url) original_uri = URI.parse(url) opts = { tags: %w[div p code pre h1 h2 h3 b em i strong a img ul li ol blockquote], attributes: %w[href src class], remove_empty_nodes: false } opts[:whitelist] = SiteSetting.embed_whitelist_selector if SiteSetting.embed_whitelist_selector.present? opts[:blacklist] = SiteSetting.embed_blacklist_selector if SiteSetting.embed_blacklist_selector.present? embed_classname_whitelist = SiteSetting.embed_classname_whitelist if SiteSetting.embed_classname_whitelist.present? response = FetchResponse.new begin html = open(url, allow_redirections: :safe).read rescue OpenURI::HTTPError, Net::OpenTimeout return end raw_doc = Nokogiri::HTML(html) auth_element = raw_doc.at('meta[@name="author"]') if auth_element.present? response.author = User.where(username_lower: auth_element[:content].strip).first end read_doc = Readability::Document.new(html, opts) title = raw_doc.title || '' title.strip! if SiteSetting.embed_title_scrubber.present? title.sub!(Regexp.new(SiteSetting.embed_title_scrubber), '') title.strip! end response.title = title doc = Nokogiri::HTML(read_doc.content) tags = { 'img' => 'src', 'script' => 'src', 'a' => 'href' } doc.search(tags.keys.join(',')).each do |node| url_param = tags[node.name] src = node[url_param] unless (src.nil? || src.empty?) begin uri = URI.parse(UrlHelper.escape_uri(src)) unless uri.host uri.scheme = original_uri.scheme uri.host = original_uri.host node[url_param] = uri.to_s end rescue URI::InvalidURIError, URI::InvalidComponentError # If there is a mistyped URL, just do nothing end end # only allow classes in the whitelist allowed_classes = if embed_classname_whitelist.blank? then [] else embed_classname_whitelist.split(/[ ,]+/i) end doc.search('[class]:not([class=""])').each do |classnode| classes = classnode[:class].split(' ').select { |classname| allowed_classes.include?(classname) } if classes.length === 0 classnode.delete('class') else classnode[:class] = classes.join(' ') end end end response.body = doc.to_html response end def self.import_remote(import_user, url, opts = nil) opts = opts || {} response = find_remote(url) return if response.nil? response.title = opts[:title] if opts[:title].present? import_user = response.author if response.author.present? TopicEmbed.import(import_user, url, response.title, response.body) end # Convert any relative URLs to absolute. RSS is annoying for this. def self.absolutize_urls(url, contents) url = normalize_url(url) uri = URI(UrlHelper.escape_uri(url)) prefix = "#{uri.scheme}://#{uri.host}" prefix << ":#{uri.port}" if uri.port != 80 && uri.port != 443 fragment = Nokogiri::HTML.fragment("
#{contents}
") fragment.css('a').each do |a| href = a['href'] if href.present? && href.start_with?('/') a['href'] = "#{prefix}/#{href.sub(/^\/+/, '')}" end end fragment.css('img').each do |a| src = a['src'] if src.present? && src.start_with?('/') a['src'] = "#{prefix}/#{src.sub(/^\/+/, '')}" end end fragment.at('div').inner_html end def self.topic_id_for_embed(embed_url) embed_url = normalize_url(embed_url).sub(/^https?\:\/\//, '') TopicEmbed.where("embed_url ~* '^https?://#{Regexp.escape(embed_url)}$'").pluck(:topic_id).first end def self.first_paragraph_from(html) doc = Nokogiri::HTML(html) result = "" doc.css('p').each do |p| if p.text.present? result << p.to_s return result if result.size >= 100 end end return result unless result.blank? # If there is no first paragaph, return the first div (onebox) doc.css('div').first end def self.expanded_for(post) Rails.cache.fetch("embed-topic:#{post.topic_id}", expires_in: 10.minutes) do url = TopicEmbed.where(topic_id: post.topic_id).pluck(:embed_url).first response = TopicEmbed.find_remote(url) body = response.body body << TopicEmbed.imported_from_html(url) body end end end # == Schema Information # # Table name: topic_embeds # # id :integer not null, primary key # topic_id :integer not null # post_id :integer not null # embed_url :string(1000) not null # content_sha1 :string(40) # created_at :datetime not null # updated_at :datetime not null # deleted_at :datetime # deleted_by_id :integer # # Indexes # # index_topic_embeds_on_embed_url (embed_url) UNIQUE #