Diffo.Provider.Extension.InheritedPartyDeclaration (Diffo v0.8.0)

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DSL entity for an inherited_party declaration inside parties do on an Instance resource.

Generates an Ash calculation of the same name as role that walks the instance graph to inherit a party from a reached instance. The calculation is injected by TransformInheritedRefs at compile time — no PartyRef edge is created on the consuming instance itself.

Fields

  • role — atom; the name of the generated calculation (and the party slot name from the consumer's perspective — the surfaced PartyRef carries this role).
  • source_role — atom; the PartyRef role to read on each reached instance (e.g. :provider). Required. This terminal deref is not a via: hop — via: reaches the instance; routing through a party (the ref graph) is calc territory (see #227).
  • via — the hop chain to the instance holding the ref, in the unified #213 grammar (shared with inherited_characteristic): a bare atom is {:reverse, assignment: alias} shorthand; tuples are {:forward | :reverse, assignment: alias} or {:forward | :reverse, relationship: type | [type: t, alias: a]}. When nil, defaults to [role]. See Diffo.Provider.Extension.Traversal.
  • collapse — :first or :last; collapses the consumer-ordered result list (the refs at source_role across reached instances) to that end. When set, the calc returns a single party or nil rather than a list.

Example

parties do
  inherited_party :provider, source_role: :provider
  inherited_party :nni_owner, via: [:uplink], source_role: :owner
  # forward relationship hop + collapse to a single owner
  inherited_party :circuit_owner,
    via: [{:forward, relationship: [alias: :circuit]}],
    source_role: :owner,
    collapse: :first
end