to-csv/index.js

Convert objects to CSV

/**
 * Module dependencies
 */

var isArray = Array.isArray
  , keys = Object.keys;

CSV.CHAR_RETURN = 0xd;
CSV.CHAR_NEWLINE = 0xa;
CSV.DELIMITER = 0x2c;
CSV.CHAR_ENCAPSULATE = 0x22;

function head (a) {
  return a[0];
}

function tail (a) {
  return a[a.length -1];
}

function char (c) {
  return 'number' === typeof c
    ? String.fromCharCode.apply(null, arguments)
    : c;
}

function needsEncapsulation (string) {
  return !!string && (
          string.toString().indexOf(char(CSV.DELIMITER)) >= 0 ||
          string.toString().indexOf(char(CSV.CHAR_RETURN)) >= 0 ||
          string.toString().indexOf(char(CSV.CHAR_NEWLINE)) >= 0 ||
          string.toString().indexOf(char(CSV.CHAR_ENCAPSULATE)) >= 0
        );
}

function encapsulate (string) {
  var wrapperChar = char(CSV.CHAR_ENCAPSULATE)
    , replaceWith = "\\" + char(CSV.CHAR_ENCAPSULATE)
    , escapedValue = string.toString().replace(new RegExp(wrapperChar, 'g'), replaceWith);

  return wrapperChar + escapedValue + wrapperChar;
}

/**
 * Parses an array of objects to a CSV output
 */

module.exports = CSV;
function CSV (objects, opts) {
  if ('object' !== typeof objects) throw new TypeError("expecting an array");

  opts = 'object' === typeof opts
    ? opts
    : {};

    objects = isArray(objects)
      ? objects.slice()
      : [objects];

      if (!objects.length) throw new Error("expecting at least one object");

      var headers = keys(head(objects))
        , buf = [];

      while (objects.length) {
        var lbuf = []
          , object = objects.shift();

        for (var i = 0 ;i < headers.length; ++i) {
          var header = headers[i];

          if (lbuf.length) lbuf.push(char(CSV.DELIMITER));
          object[header] = needsEncapsulation(object[header])
            ? encapsulate(object[header])
            : object[header];

            lbuf.push(object[header]);
        }

        buf.push(lbuf.join(''));
        buf.push(char(CSV.CHAR_RETURN, CSV.CHAR_NEWLINE));
      }

      return false !== opts.headers
        ? [].concat(headers.join(char(CSV.DELIMITER)), char(CSV.CHAR_NEWLINE)).concat(buf).filter(Boolean).join('')
        : buf.filter(Boolean).join('');
}