This module is a code generator for Drupal developers.. It generates much of the code needed to create custom field types, as a fully-working, downloadable module.
It has some very interesting features, like support, out of the box, for the following data fields as columns of the field type created:
1.- "text_format" Textareas that need to store the chosen format.
2.- Date fields (https://www.drupal.org/project/date)
3.- Entity Reference fields