Diffo.Provider.DefinedSimpleRelationship (Diffo v0.4.0)

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Ash Resource for a relationship with an optional single embedded characteristic, set at creation and never changed.

Extends BaseRelationship (source, target, type, timestamps). Optionally carries one DefinedCharacteristic — a name/value pair stored directly on the Neo4j node. The value is a Diffo.Type.Primitive, covering string, integer, float, boolean, and temporal types.

Actions: create and destroy only. No update, no relate/unrelate. Once defined, the characteristic is closed — that is the commitment.

Contrast with Provider.Relationship which allows mutable graph-based Characteristic nodes to be added, removed, and updated over time.

DefinedSimpleRelationship is a general Provider primitive for any relationship whose characteristic is a commitment or promise made at creation time.

An Ash Resource for a relationship with a single optional characteristic, defined at creation and closed thereafter

Summary

Types

t()

Functions

default_short_name()
input(opts)

Validates that the keys in the provided input are valid for at least one action on the resource.

input(opts, action)

Same as input/1, except restricts the keys to values accepted by the action provided.

primary_key_matches?(left, right)

Types

t()

@type t() :: %Diffo.Provider.DefinedSimpleRelationship{
  __lateral_join_source__: term(),
  __meta__: term(),
  __metadata__: term(),
  __order__: term(),
  aggregates: term(),
  alias: term(),
  calculations: term(),
  characteristic: term(),
  created_at: term(),
  id: term(),
  source: term(),
  source_id: term(),
  target: term(),
  target_href: term(),
  target_id: term(),
  target_type: term(),
  type: term(),
  updated_at: term()
}

Functions

default_short_name()

input(opts)

@spec input(values :: map() | Keyword.t()) :: map() | no_return()

Validates that the keys in the provided input are valid for at least one action on the resource.

Raises a KeyError error at compile time if not. This exists because generally a struct should only ever be created by Ash as a result of a successful action. You should not be creating records manually in code, e.g %MyResource{value: 1, value: 2}. Generally that is fine, but often with embedded resources it is nice to be able to validate the keys that are being provided, e.g

Resource
|> Ash.Changeset.for_create(:create, %{embedded: EmbeddedResource.input(foo: 1, bar: 2)})
|> Ash.create()

input(opts, action)

@spec input(values :: map() | Keyword.t(), action :: atom()) :: map() | no_return()

Same as input/1, except restricts the keys to values accepted by the action provided.

primary_key_matches?(left, right)