discourse/lib/onebox/preview.rb

102 lines
2.4 KiB
Ruby

# frozen_string_literal: true
module Onebox
class Preview
# see https://bugs.ruby-lang.org/issues/14688
client_exception = defined?(Net::HTTPClientException) ? Net::HTTPClientException : Net::HTTPServerException
WEB_EXCEPTIONS ||= [client_exception, OpenURI::HTTPError, Timeout::Error, Net::HTTPError, Errno::ECONNREFUSED]
def initialize(url, options = Onebox.options)
@url = url
@options = options.dup
allowed_origins = @options[:allowed_iframe_origins] || Onebox::Engine.all_iframe_origins
@options[:allowed_iframe_regexes] = Engine.origins_to_regexes(allowed_origins)
@engine_class = Matcher.new(@url, @options).oneboxed
end
def to_s
return "" unless engine
sanitize process_html engine_html
rescue *WEB_EXCEPTIONS
""
end
def placeholder_html
return "" unless engine
sanitize process_html engine.placeholder_html
rescue *WEB_EXCEPTIONS
""
end
def errors
return {} unless engine
engine.errors
end
def data
return {} unless engine
engine.data
end
def verified_data
return {} unless engine
engine.verified_data
end
def options
OpenStruct.new(@options)
end
private
def engine_html
engine.to_html
end
def process_html(html)
return "" unless html
if @options[:max_width]
doc = Nokogiri::HTML5::fragment(html)
if doc
doc.css('[width]').each do |e|
width = e['width'].to_i
if width > @options[:max_width]
height = e['height'].to_i
if (height > 0)
ratio = (height.to_f / width.to_f)
e['height'] = (@options[:max_width] * ratio).floor
end
e['width'] = @options[:max_width]
end
end
return doc.to_html
end
end
html
end
def sanitize(html)
config = @options[:sanitize_config] || SanitizeConfig::ONEBOX
config = config.merge(allowed_iframe_regexes: @options[:allowed_iframe_regexes])
Sanitize.fragment(html, config)
end
def engine
return nil unless @engine_class
return @engine if defined?(@engine)
@engine = @engine_class.new(@url)
@engine.options = @options
@engine
end
class InvalidURI < StandardError; end
end
end