complex data structure json to form data

json-to-formdata.js

function jsonToFormData($json) {
  function isObject($o) { return typeof $o === 'object' && $o !== null; }
  function isFunction($o) { return typeof $o === 'function'; }
  function visit($json, $arr, $prefix) {
    var t0, i, j;
    t0 = $arr || [];
    $prefix = $prefix || '';
    for (i in $json) {
      if (isFunction($json[i])) continue;
      if ( Array.isArray($json[i]) ) {
        for (j in $json[i]) {
          if (isFunction($json[i][j])) continue;
          if ( isObject($json[i][j]) ) 
            t0.concat(visit($json[i][j], t0, (($prefix ? $prefix + '.' : '') + i + '[' + j +']'))); 
          else 
            t0.push(($prefix ? $prefix + '.' : '') + i +'[' + j + ']' + '=' + encodeURIComponent($json[i][j]));
        }
        $prefix = $prefix || '';
        continue;
      }
      if ( isObject($json[i]) ) t0.concat(visit($json[i], t0, (($prefix ? $prefix + '.' : '') + j)));
      else t0.push(($prefix ? $prefix + '.' : '') + i + '=' + encodeURIComponent($json[i]));
    }
    return t0;
  }
  return visit($json).join('&');
}

console.log(jsonToFormData({data:[{a:1, b:2, c:3}, {a:2, b:3, c:4}], msg:'aa'}));  
// data[0].a=1&data[0].b=2&data[0].c=3&data[1].a=2&data[1].b=3&data[1].c=4&msg=aa 

깊은 depth일때 배열 순회후 attribute가 최상위 node 에 붙는 문제 수정