discourse/lib/pretty_text.rb

369 lines
10 KiB
Ruby

require 'v8'
require 'nokogiri'
require_dependency 'url_helper'
require_dependency 'excerpt_parser'
require_dependency 'post'
module PrettyText
class Helpers
include UrlHelper
def t(key, opts)
key = "js." + key
unless opts
return I18n.t(key)
else
str = I18n.t(key, Hash[opts.entries].symbolize_keys).dup
opts.each {|k,v| str.gsub!("{{#{k.to_s}}}", v.to_s) }
return str
end
end
# functions here are available to v8
def avatar_template(username)
return "" unless username
user = User.find_by(username_lower: username.downcase)
return "" unless user.present?
# TODO: Add support for ES6 and call `avatar-template` directly
if !user.uploaded_avatar_id && SiteSetting.default_avatars.present?
split_avatars = SiteSetting.default_avatars.split("\n")
if split_avatars.present?
hash = username.each_char.reduce(0) do |result, char|
[((result << 5) - result) + char.ord].pack('L').unpack('l').first
end
avatar_template = split_avatars[hash.abs % split_avatars.size]
end
else
avatar_template = user.avatar_template
end
schemaless absolute avatar_template
end
def is_username_valid(username)
return false unless username
username = username.downcase
User.exec_sql('SELECT 1 FROM users WHERE username_lower = ?', username).values.length == 1
end
end
@mutex = Mutex.new
@ctx_init = Mutex.new
def self.mention_matcher
Regexp.new("(\@[a-zA-Z0-9_]{#{User.username_length.begin},#{User.username_length.end}})")
end
def self.app_root
Rails.root
end
def self.create_new_context
# timeout any eval that takes longer that 5 seconds
ctx = V8::Context.new(timeout: 5000)
ctx["helpers"] = Helpers.new
ctx_load(ctx,
"vendor/assets/javascripts/md5.js",
"vendor/assets/javascripts/lodash.js",
"vendor/assets/javascripts/Markdown.Converter.js",
"lib/headless-ember.js",
"vendor/assets/javascripts/rsvp.js",
Rails.configuration.ember.handlebars_location
)
ctx.eval("var Discourse = {}; Discourse.SiteSettings = {};")
ctx.eval("var window = {}; window.devicePixelRatio = 2;") # hack to make code think stuff is retina
ctx.eval("var I18n = {}; I18n.t = function(a,b){ return helpers.t(a,b); }");
ctx.eval("var modules = {};")
decorate_context(ctx)
ctx_load(ctx,
"vendor/assets/javascripts/better_markdown.js",
"app/assets/javascripts/defer/html-sanitizer-bundle.js",
"app/assets/javascripts/discourse/dialects/dialect.js",
"app/assets/javascripts/discourse/lib/utilities.js",
"app/assets/javascripts/discourse/lib/html.js",
"app/assets/javascripts/discourse/lib/markdown.js",
)
Dir["#{app_root}/app/assets/javascripts/discourse/dialects/**.js"].sort.each do |dialect|
ctx.load(dialect) unless dialect =~ /\/dialect\.js$/
end
# emojis
emoji = ERB.new(File.read("#{app_root}/app/assets/javascripts/discourse/lib/emoji/emoji.js.erb"))
ctx.eval(emoji.result)
# Load server side javascripts
if DiscoursePluginRegistry.server_side_javascripts.present?
DiscoursePluginRegistry.server_side_javascripts.each do |ssjs|
if(ssjs =~ /\.erb/)
erb = ERB.new(File.read(ssjs))
erb.filename = ssjs
ctx.eval(erb.result)
else
ctx.load(ssjs)
end
end
end
ctx['quoteTemplate'] = File.read("#{app_root}/app/assets/javascripts/discourse/templates/quote.hbs")
ctx['quoteEmailTemplate'] = File.read("#{app_root}/lib/assets/quote_email.hbs")
ctx.eval("HANDLEBARS_TEMPLATES = {
'quote': Handlebars.compile(quoteTemplate),
'quote_email': Handlebars.compile(quoteEmailTemplate),
};")
ctx
end
def self.v8
return @ctx if @ctx
# ensure we only init one of these
@ctx_init.synchronize do
return @ctx if @ctx
@ctx = create_new_context
end
@ctx
end
def self.reset_context
@ctx_init.synchronize do
@ctx = nil
end
end
def self.decorate_context(context)
context.eval("Discourse.SiteSettings = #{SiteSetting.client_settings_json};")
context.eval("Discourse.CDN = '#{Rails.configuration.action_controller.asset_host}';")
context.eval("Discourse.BaseUrl = 'http://#{RailsMultisite::ConnectionManagement.current_hostname}';")
context.eval("Discourse.getURL = function(url) { return '#{Discourse::base_uri}' + url };")
context.eval("Discourse.getURLWithCDN = function(url) { url = Discourse.getURL(url); if (Discourse.CDN) { url = Discourse.CDN + url; } return url; };")
end
def self.markdown(text, opts=nil)
# we use the exact same markdown converter as the client
# TODO: use the same extensions on both client and server (in particular the template for mentions)
baked = nil
protect do
context = v8
# we need to do this to work in a multi site environment, many sites, many settings
decorate_context(context)
context_opts = opts || {}
context_opts[:sanitize] ||= true
context['opts'] = context_opts
context['raw'] = text
if Post.white_listed_image_classes.present?
Post.white_listed_image_classes.each do |klass|
context.eval("Discourse.Markdown.whiteListClass('#{klass}')")
end
end
# custom emojis
Emoji.custom.each do |emoji|
context.eval("Discourse.Dialect.registerEmoji('#{emoji.name}', '#{emoji.url}');")
end
context.eval('opts["mentionLookup"] = function(u){return helpers.is_username_valid(u);}')
context.eval('opts["lookupAvatar"] = function(p){return Discourse.Utilities.avatarImg({size: "tiny", avatarTemplate: helpers.avatar_template(p)});}')
baked = context.eval('Discourse.Markdown.markdownConverter(opts).makeHtml(raw)')
end
if baked.blank? && !(opts || {})[:skip_blank_test]
# we may have a js engine issue
test = markdown("a", skip_blank_test: true)
if test.blank?
Rails.logger.warn("Markdown engine appears to have crashed, resetting context")
reset_context
opts ||= {}
opts = opts.dup
opts[:skip_blank_test] = true
baked = markdown(text, opts)
end
end
baked
end
# leaving this here, cause it invokes v8, don't want to implement twice
def self.avatar_img(avatar_template, size)
protect do
v8['avatarTemplate'] = avatar_template
v8['size'] = size
decorate_context(v8)
v8.eval("Discourse.Utilities.avatarImg({ avatarTemplate: avatarTemplate, size: size });")
end
end
def self.cook(text, opts={})
cloned = opts.dup
# we have a minor inconsistency
cloned[:topicId] = opts[:topic_id]
sanitized = markdown(text.dup, cloned)
sanitized = add_rel_nofollow_to_user_content(sanitized) if !cloned[:omit_nofollow] && SiteSetting.add_rel_nofollow_to_user_content
sanitized
end
def self.add_rel_nofollow_to_user_content(html)
whitelist = []
domains = SiteSetting.exclude_rel_nofollow_domains
whitelist = domains.split('|') if domains.present?
site_uri = nil
doc = Nokogiri::HTML.fragment(html)
doc.css("a").each do |l|
href = l["href"].to_s
begin
uri = URI(href)
site_uri ||= URI(Discourse.base_url)
if !uri.host.present? ||
uri.host.ends_with?(site_uri.host) ||
whitelist.any?{|u| uri.host.ends_with?(u)}
# we are good no need for nofollow
else
l["rel"] = "nofollow"
end
rescue URI::InvalidURIError, URI::InvalidComponentError
# add a nofollow anyway
l["rel"] = "nofollow"
end
end
doc.to_html
end
class DetectedLink
attr_accessor :is_quote, :url
def initialize(url, is_quote=false)
@url = url
@is_quote = is_quote
end
end
def self.extract_links(html)
links = []
doc = Nokogiri::HTML.fragment(html)
# remove href inside quotes
doc.css("aside.quote a").each { |l| l["href"] = "" }
# extract all links from the post
doc.css("a").each { |l|
unless l["href"].blank?
links << DetectedLink.new(l["href"])
end
}
# extract links to quotes
doc.css("aside.quote[data-topic]").each do |a|
topic_id = a['data-topic']
url = "/t/topic/#{topic_id}"
if post_number = a['data-post']
url << "/#{post_number}"
end
links << DetectedLink.new(url, true)
end
links
end
def self.excerpt(html, max_length, options={})
# TODO: properly fix this HACK in ExcerptParser without introducing XSS
doc = Nokogiri::HTML.fragment(html)
strip_image_wrapping(doc)
html = doc.to_html
ExcerptParser.get_excerpt(html, max_length, options)
end
def self.strip_links(string)
return string if string.blank?
# If the user is not basic, strip links from their bio
fragment = Nokogiri::HTML.fragment(string)
fragment.css('a').each {|a| a.replace(a.inner_html) }
fragment.to_html
end
# Given a Nokogiri doc, convert all links to absolute
def self.make_all_links_absolute(doc)
site_uri = nil
doc.css("a").each do |link|
href = link["href"].to_s
begin
uri = URI(href)
site_uri ||= URI(Discourse.base_url)
link["href"] = "#{site_uri}#{link['href']}" unless uri.host.present?
rescue URI::InvalidURIError, URI::InvalidComponentError
# leave it
end
end
end
def self.strip_image_wrapping(doc)
doc.css(".lightbox-wrapper .meta").remove
end
def self.format_for_email(html)
doc = Nokogiri::HTML.fragment(html)
make_all_links_absolute(doc)
strip_image_wrapping(doc)
doc.to_html
end
protected
class JavaScriptError < StandardError
attr_accessor :message, :backtrace
def initialize(message, backtrace)
@message = message
@backtrace = backtrace
end
end
def self.protect
rval = nil
@mutex.synchronize do
begin
rval = yield
# This may seem a bit odd, but we don't want to leak out
# objects that require locks on the v8 vm, to get a backtrace
# you need a lock, if this happens in the wrong spot you can
# deadlock a process
rescue V8::Error => e
raise JavaScriptError.new(e.message, e.backtrace)
end
end
rval
end
def self.ctx_load(ctx, *files)
files.each do |file|
ctx.load(app_root + file)
end
end
end