question Do traits still use the legacy API? in Support Questions

Do traits still use the legacy API?

laura_ngo — Tue, 13 Jun 2017 02:00:25 GMT

I'm looking at the documentation for HDP 2.6.1 and from what I can see, traits still use the legacy API rather than v2. Am I reading the documentation correctly?

In section 'Atlas types' it states that composite metatypes are "Class, Struct, Trait".

e.g.

POST v2/types/classificationdef 

POST /v2/types/structdef

But v2 REST API doesn't have anything for 'trait'

In section 'Cataloging Atlas Metadata: Traits and Business Taxonomy' we have:

POST http://<atlas-server-host:port>/api/atlas/types

So this is using the legacy API. Is this right? Will this change with future Atlas releases?

Also, can someone provide a business use case for using classifications, structs and traits. I'm getting muddled between the circumstances I would use each. Many thanks!

Re: Do traits still use the legacy API?

ssubramanian — Tue, 13 Jun 2017 02:38:43 GMT

Hi @Laura Ngo,

The documentation for 'Atlas types' is still not updated with v2 types. It should ideally be - "Composite metatypes – Entity, Struct and Classification"

Struct Type:

You cannot create instances for Struct types as they do not have an identity of their own (it doesn't have a GUID), it always exists with an entity. e.g. entity attribute can be of type struct.

Classification type:

Each classification instance is associated with an entity. The v2 type name for "trait" is "classification" and it is derived from Struct. e.g. Associate tag/classification to an entity.

Checkout Working with Atlas Tags to know more about how you can assign tag/classification to an entity.