Cross-Service References

Habarico::ActiveModel::References is a mixin for non-ActiveRecord models that need to declare references to records managed by another service. Include it in your model class to get a DSL for registering cross-service associations.

class OrderDocument
  include Habarico::ActiveModel::References

  has_one_reference  :order,   'Order'
  has_many_reference :signers, 'Contact'
end

Class methods provided by the mixin:

Method	Description
has_one_reference(name, class_name)	Declare a has-one cross-service reference. Creates an underlying string attribute to hold the remote ID.
has_many_reference(name, class_name)	Declare a has-many cross-service reference. Creates an array-of-strings attribute for IDs and a companion __items reference for metadata.
references(type: nil)	Return all declared references, optionally filtered by :has_one or :has_many.
reference_names(type: nil)	Return an array of reference name symbols.
has_reference?(name, type: nil)	Check whether a reference with the given name exists.
find_reference(name, type: nil)	Return the reference definition hash for the named reference.

This module extends Eluvia::ActiveModel::Attributes and Eluvia::ActiveModel::ArrayAttribute for attribute storage.

Permissions on the referenced resource

The frontend resolves a reference into a display label by fetching the referenced records with an id__in filter on the target resource's list endpoint. When the target resource denies can_read, that fetch is forbidden too — set allow_read_by_id true on the target resource to allow ID-based reads without list access. See Permissions for the exact semantics.