class SearchObserver < ActiveRecord::Observer observe :topic, :post, :user, :category def self.scrub_html_for_search(html) HtmlScrubber.scrub(html) end def self.update_index(table, id, search_data) table_name = "#{table}_search_data" foreign_key = "#{table}_id" # Would be nice to use AR here but not sure how to execut Postgres functions # when inserting data like this. rows = Post.exec_sql_row_count("UPDATE #{table_name} SET search_data = TO_TSVECTOR('english', ?) WHERE #{foreign_key} = ?", search_data, id) if rows == 0 Post.exec_sql("INSERT INTO #{table_name} (#{foreign_key}, search_data) VALUES (?, TO_TSVECTOR('english', ?))", id, search_data) end rescue # don't allow concurrency to mess up saving a post end def self.update_posts_index(post_id, cooked, title, category) search_data = scrub_html_for_search(cooked) << " " << title search_data << " " << category if category update_index('post', post_id, search_data) end def self.update_users_index(user_id, username, name) search_data = username.dup << " " << (name || "") update_index('user', user_id, search_data) end def self.update_categories_index(category_id, name) update_index('category', category_id, name) end def after_save(obj) if obj.class == Post && obj.cooked_changed? category_name = obj.topic.category.name if obj.topic.category SearchObserver.update_posts_index(obj.id, obj.cooked, obj.topic.title, category_name) end if obj.class == User && (obj.username_changed? || obj.name_changed?) SearchObserver.update_users_index(obj.id, obj.username, obj.name) end if obj.class == Topic && obj.title_changed? if obj.posts post = obj.posts.where(post_number: 1).first if post category_name = obj.category.name if obj.category SearchObserver.update_posts_index(post.id, post.cooked, obj.title, category_name) end end end if obj.class == Category && obj.name_changed? SearchObserver.update_categories_index(obj.id, obj.name) end end class HtmlScrubber < Nokogiri::XML::SAX::Document attr_reader :scrubbed def initialize @scrubbed = "" end def self.scrub(html) me = new parser = Nokogiri::HTML::SAX::Parser.new(me) begin copy = "
" copy << html unless html.nil? copy << "
" parser.parse(html) unless html.nil? end me.scrubbed end def start_element(name, attributes=[]) attributes = Hash[*attributes.flatten] if attributes["alt"] scrubbed << " " scrubbed << attributes["alt"] scrubbed << " " end if attributes["title"] scrubbed << " " scrubbed << attributes["title"] scrubbed << " " end end def characters(string) scrubbed << " " scrubbed << string scrubbed << " " end end end