Created
June 9, 2013 20:13
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SearchObserver starting point
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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 = "<div>" | |
copy << html unless html.nil? | |
copy << "</div>" | |
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 |
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