Entity Data Attach

Entity Data Attach provides a field type and a plugin API for attaching custom sets of data to any type of fieldable entity.

It is similar to views field except that
a) The attachments can be anything defined in a callback of a EntityDataAttach plugin
b) It provides data, not markup

This is a developer-centric module. Developer can define new EntityDataAttach plugins to provide any type of data attachment.

The intended use case is for linking dynamic data segments to content like nodes or paragraphs for a decoupled frontend to consume.

To see what it does:
1) Enable the module
2) Add a "data attach" field to a content type
3) Add some content and set the data attach value to the example attachment
4) Enable the Data Attach Example rest resource
5) Hit the GET resource and you'll see the data from the attachment.