flattens javascript object to work with expressjs body-parser with `extended: true`

object-flatten.js

function flattenObject(obj, prefix) {
  var toReturn = {};

  for (var i in obj) {
    if (!obj.hasOwnProperty(i)) continue;

    if ((typeof obj[i]) == 'object') {
      var flatObject;
      if (prefix) {
        prefix = prefix + '[' + i + ']';
      } else {
        prefix = i;
      }
      flatObject = flattenObject(obj[i], prefix);
      for (var x in flatObject) {
        if (!flatObject.hasOwnProperty(x)) continue;

        if (x.indexOf('[') > -1) {
          toReturn[x] = flatObject[x];
        } else {
          toReturn[prefix + '[' + x + ']'] = flatObject[x];
        }
      }
    } else {
      toReturn[i] = obj[i];
    }
  }
  return toReturn;
}

/*

flattenObject({a: "b", c: { d: "e", f: "g", h:{i: "j", l: "m", o: {p: "q", r: "s"}}}});

-> {"a":"b","c[d]":"e","c[f]":"g","c[h][i]":"j","c[h][l]":"m","c[h][o][p]":"q","c[h][o][r]":"s"}


*/