Function getMessage

lib/wechat.js:78–88

(stream, callback)

 * 从微信的提交中提取XML文件
 */
var getMessage = function (stream, callback) {
  var buf = new BufferHelper();
  buf.load(stream, function (err, buf) {
    if (err) {
      return callback(err);
    }
    var xml = buf.toString('utf-8');
    stream.weixin_xml = xml;
    xml2js.parseString(xml, {trim: true}, callback);
  });
};

/*!
 * 检查对象是否为空，对xml2js的workaround