form_data_serializer.js

/*
 * Serialize value
 */
function serializeValue(key, value, formData) {
  if(value) {
    if($.type(value) == "string" || $.type(value) == 'number' || value.constructor == File) {
      formData.append(key, value);
    }
    else if($.type(value) == "array") {
      serializeArray(key, value, formData);
    }
    else if(value.constructor == Object) {
      serializeNestedObject(key, value, formData);
    }
    else {
      formData.append(key, JSON.stringify(value));
    }
  }
  else {
    formData.append(key, "");
  }
}

/*
 * Serialize array
 */
function serializeArray(key, array, formData) {
  if(array.length > 0) {
    array.forEach(function(value) {
      serializeValue(key + '[]', value, formData);
    });
  }
  else {
    // formData.append(key + '[]', "");
  }
}

/*
 * Serialize nested object
 */
function serializeNestedObject(parent_key, object, formData) {
  for (var key in object) {
    serializeValue(parent_key + '[' + key + ']', object[key], formData);
  }
}


/*
 * Serialize object
 */
function serializeObject(object) {
  var formData = new FormData();

  for (var key in object) {
    serializeValue(key, object[key], formData);
  }

  return formData;
}