Google Translate script

translate.js

function translate(text, callback) {
  var xhr = new XMLHttpRequest();
  xhr.open('POST', 'https://www.google.com/async/translate?');
  var data = 'async=translate,sl:auto,tl:en,st:' + encodeURIComponent(text) + ',id:0,_id:tw-async-translate,_pms:s';
  xhr.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded;charset=utf-8');
  xhr.onreadystatechange = function() {
    if (xhr.readyState === 4 && xhr.status === 200) {
      a = JSON.parse(xhr.responseText);
      var doc = document.implementation.createHTMLDocument();
      doc.body.innerHTML = JSON.parse(xhr.responseText)[1][1];
      var translation = doc.querySelector('#tw-answ-target-text').textContent;
      callback(translation);
    }
  };
  xhr.send(data);
}

translate('これは、Google翻訳のためのテストです。', function(result) {
  console.log('"%s"', result);
});