I want to emphasise that I don't want to use
I want to create custom field type that can be reused in different entities and bundles. This should be kept in one custom module. So when I enable it and go to 'manage fields' page on any entity type then I should be able to pick up my custom field type (e.g.:
foo). This field should be combined with base image field and simple one line text field. I don't want to use
field_collection module because as far as I see I can not recreate my field, even features give me ability to export it in
field_base section. After flushing my drupal to clean instance and enabling this feature again I can not see it in 'Add existing field' in [structure > content types > CONTENT_TYPE > manage fields] page. Maybe I'm doing something wrong. (?)
So how can I programmatically create custom field type with existing base fields? e.g. Custom
foo field type with image field and text field?
OR (if I done something wrong with features..)
How can I export custom field collection with sub fields, only as a field definition (not attached to any content type/entity) using features?