Class: Pollex::Translator

Inherits:
Object
  • Object
show all
Includes:
Singleton
Defined in:
lib/pollex/translator.rb

Overview

Singleton object for translating descriptions into English.

Instance Method Summary collapse

Constructor Details

#initialize ⇒ Translator

Instantiates a cache of size 100 for storing translations.



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# File 'lib/pollex/translator.rb', line 7

def initialize()
  @cache = LRUCache.new(:max_size => 2500, :default => nil)
end

Instance Method Details

#translate(phrase, source_lang_code, context = nil) ⇒ Object

Note:

MyMemory currently has a limit of 100 API requests per IP per day for unregistered users.

Translates a phrase into English using the free MyMemory API, and caches the result.

Parameters:

  • phrase (String) —

    Phrase to be translated

  • source_lang_code (String) —

    Two-letter language code for the source language

  • context (Array<String>) (defaults to: nil) —

    Adjoining phrases (optional)



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# File 'lib/pollex/translator.rb', line 19

def translate(phrase, source_lang_code, context = nil)
  context ||= [phrase]
  if context.all? {|x| CLD.detect_language(x)[:code] == 'en'}
    # we are reasonably sure that this phrase is already in English - no need to translate
    phrase
  else
    # first, check the cache
    key = [phrase, source_lang_code]
    if @cache[key]
      @cache[key]
    else
      # make a request to MyMemory
      puts "Translating '#{phrase}' from (#{source_lang_code}) ..."
      url = "http://mymemory.translated.net/api/get?q=#{URI::encode(phrase)}&langpair=#{source_lang_code}%7Cen"
      results_json = open(url).read
      result = JSON.parse(results_json)['responseData']['translatedText']

      if result.include? 'MYMEMORY WARNING'
        # translation failed - return original phrase
        puts result
        phrase
      else
        # translation succeeded - store into cache and return translated phrase
        @cache[key] = result
        result
      end
    end
  end
end