Async 모듈 사용 후 도서 검색 코드

withAsync.js

appendBookId(booklist, body);

var tasks = [];

_.each(booklist, function(book, key) {
  var o = _.clone(opt);
  o.bookId = book.bookId;
  tasks.push(function (callback) {
    searchDetail(o, function (err, exist) {
      if (err) {
        exist = false;
      }
      callback(null, exist);
    });
  })
});

async.parallel(tasks, function (err, results) {
  if (err) {
    getBook({msg: 'Error, Can\'t access detail information'});
    return;
  }
  if (getBook) {
    booklist = _.map(booklist, function (item, key) {
      item.exist = results[key];
      return item;
    });
    getBook(null, {
      startPage: opt.startPage,
      totalBookCount: totalBookCount,
      booklist: booklist
    });
  }
});