forked from fedi/mastodon
38e9662d78
If the input text is blank after preparation (only mention, or only URL, or empty as in a media post), then use nil as language, since it's OK to show to everyone. Otherwise, always fall back to the server's default locale
81 lines
1.8 KiB
Ruby
81 lines
1.8 KiB
Ruby
# frozen_string_literal: true
|
|
|
|
class LanguageDetector
|
|
include Singleton
|
|
|
|
CHARACTER_THRESHOLD = 140
|
|
|
|
def initialize
|
|
@identifier = CLD3::NNetLanguageIdentifier.new(1, 2048)
|
|
end
|
|
|
|
def detect(text, account)
|
|
input_text = prepare_text(text)
|
|
return if input_text.blank?
|
|
detect_language_code(input_text) || default_locale(account)
|
|
end
|
|
|
|
def language_names
|
|
@language_names =
|
|
CLD3::TaskContextParams::LANGUAGE_NAMES.map { |name| iso6391(name.to_s).to_sym }
|
|
.uniq
|
|
end
|
|
|
|
private
|
|
|
|
def prepare_text(text)
|
|
simplify_text(text).strip
|
|
end
|
|
|
|
def unreliable_input?(text)
|
|
text.size < CHARACTER_THRESHOLD
|
|
end
|
|
|
|
def detect_language_code(text)
|
|
return if unreliable_input?(text)
|
|
result = @identifier.find_language(text)
|
|
iso6391(result.language.to_s).to_sym if result.reliable?
|
|
end
|
|
|
|
def iso6391(bcp47)
|
|
iso639 = bcp47.split('-').first
|
|
|
|
# CLD3 returns grandfathered language code for Hebrew
|
|
return 'he' if iso639 == 'iw'
|
|
|
|
ISO_639.find(iso639).alpha2
|
|
end
|
|
|
|
def simplify_text(text)
|
|
new_text = remove_html(text)
|
|
new_text.gsub!(FetchLinkCardService::URL_PATTERN, '')
|
|
new_text.gsub!(Account::MENTION_RE, '')
|
|
new_text.gsub!(Tag::HASHTAG_RE, '')
|
|
new_text.gsub!(/:#{CustomEmoji::SHORTCODE_RE_FRAGMENT}:/, '')
|
|
new_text.gsub!(/\s+/, ' ')
|
|
new_text
|
|
end
|
|
|
|
def new_scrubber
|
|
scrubber = Rails::Html::PermitScrubber.new
|
|
scrubber.tags = %w(br p)
|
|
scrubber
|
|
end
|
|
|
|
def scrubber
|
|
@scrubber ||= new_scrubber
|
|
end
|
|
|
|
def remove_html(text)
|
|
text = Loofah.fragment(text).scrub!(scrubber).to_s
|
|
text.gsub!('<br>', "\n")
|
|
text.gsub!('</p><p>', "\n\n")
|
|
text.gsub!(/(^<p>|<\/p>$)/, '')
|
|
text
|
|
end
|
|
|
|
def default_locale(account)
|
|
account.user_locale&.to_sym || I18n.default_locale
|
|
end
|
|
end
|