Relation feature will be revisited on the LTS 2019 cycle, thus there will be no work done on Web UI in LTS 2018 on this topic Nevertheless, the relation engine is still in the product and is maintained and there is already a set of operations that can be used to achieve the purpose in a custom manner. It is a small development.

Operations to manage relations are: Create: https://nuxeo.github.io/api-playground/#/commands/Document.AddRelation
Get: https://nuxeo.github.io/api-playground/#/commands/Document.GetLinkedDocuments
Delete: https://nuxeo.github.io/api-playground/#/commands/Document.DeleteRelation

Also, in JSF, the predicates are managed via a directory, but this is purely for some UI reasons, there is no need of such UI, you can set a string as predicate directly in the operation when setting it.

Finally, you may prefer to use a document reference straight into your data model (a property of type “Document” defined in Studio instead of using the relation service.

• Pros of the relation service:

  • once the relation is set, it is available in both ways easily.
  • user doesn't need to have the Write permission on the documents to set the relation

• Cons:

  • No possibility to use NXQL for fetching the linked documents
  • More custom UI to build for selecting the target document (out of the box with the document reference solution)

For the LTS 2019 cycle, we will probably re-add the relation feature in Web UI, but very likely in a simplified manner, just with the “this document is linked with " predicate.

See also the university video: https://university.nuxeo.com/learn/course/internal/view/elearning/148/expert-session-creating-nuxeo-elements-with-studio-designer