hometown/app/services/fetch_link_card_service.rb
2017-04-23 19:08:59 +02:00

39 lines
1.4 KiB
Ruby

# frozen_string_literal: true
class FetchLinkCardService < BaseService
URL_PATTERN = %r{https?://\S+}
USER_AGENT = "#{HTTP::Request::USER_AGENT} (Mastodon/#{Mastodon::VERSION}; +http://#{Rails.configuration.x.local_domain}/)"
def call(status)
# Get first http/https URL that isn't local
url = status.text.match(URL_PATTERN).to_a.reject { |uri| TagManager.instance.local_url?(uri) }.first
return if url.nil?
response = http_client.get(url)
return if response.code != 200 || response.mime_type != 'text/html'
page = Nokogiri::HTML(response.to_s)
card = PreviewCard.where(status: status).first_or_initialize(status: status, url: url)
card.title = meta_property(page, 'og:title') || page.at_xpath('//title')&.content
card.description = meta_property(page, 'og:description') || meta_property(page, 'description')
card.image = URI.parse(meta_property(page, 'og:image')) if meta_property(page, 'og:image')
return if card.title.blank?
card.save_with_optional_image!
end
private
def http_client
HTTP.headers(user_agent: USER_AGENT).timeout(:per_operation, write: 10, connect: 10, read: 10).follow
end
def meta_property(html, property)
html.at_xpath("//meta[@property=\"#{property}\"]")&.attribute('content')&.value || html.at_xpath("//meta[@name=\"#{property}\"]")&.attribute('content')&.value
end
end