sails.js CSV response type

csv.js

/**
 * 200 (OK) CSV Response
 *
 * Usage:
 * return res.csv(data);
 *
 * @param  {Object} data
 *          - must be an object array
 * @param  {String|Object} options
 *          - columns : column names we want for the CSV must be a string array
 */

module.exports = function sendCsv (data, options) {


  // Get access to `req`, `res`, & `sails`
  var req = this.req
  ,   res = this.res
  ,   sails = req._sails
  ,   json2csv = require('json2csv')
  ,   fs = require('fs')
  ,   download_dir = '.tmp/downloads/'
  ,   filename = options && options.filename ? options.filename : 'file_' + ((new Date().getTime().toString())) + '.csv'
  ,   fullpath = download_dir + filename;

  sails.log.silly('res.csv() :: Sending 200 ("OK") response');

  //PUT THE DATA THROGH THE GAUNTLET...

  if(!data){
    throw new Error('data cannot be null');
  }

  if(!_.isArray(data)){
    throw new Error('data must be of type array');
  }

  var columns = data.length ? _.keys(data[0]) : [];

  // if we made it this far, send the file

  // Set status code
  res.status(200);

  json2csv({data: data, fields: columns}, function(err, csv) {

    if (err) { throw err; }

    //make the download dir if it doesnt exist
    fs.mkdir(download_dir, 0777, function(err){
      if(err){
        //we dont care if the directory already exists.
        if (err.code !== 'EEXIST'){
          throw err;
        }
      }

      //create the csv file and upload it to our directory
      fs.writeFile(fullpath, csv, function(err) {
        if (err) throw err;
        sails.log.silly('file saved to ' + fullpath);
        res.download(fullpath, filename, function(err){
          if(err) {
            throw err;
            return;
          }

          //delete the file after we are done with it.
          fs.unlink(fullpath);

        });
      });

    });



  });
};

depends on json2csv node module