# `Diffo.Provider.Resource`
[🔗](https://github.com/diffo-dev/diffo/blob/v0.9.0/lib/diffo/provider/components/resource.ex#L5)

Ash Resource Fragment for the Resource half of the Instance cascade (TMF639).

Compose with `Diffo.Provider.BaseInstance` on a concrete Resource leaf to get the
resource lifecycle state, the `lifecycle` action, and the TMF639-shaped jason
wire form:

    defmodule MyApp.Card do
      use Ash.Resource,
        fragments: [Diffo.Provider.BaseInstance, Diffo.Provider.Resource],
        domain: MyApp.Domain

      provider do
        specification do
          id "..."
          name "card"
          type :resourceSpecification
        end
        # characteristics / features / parties / places / behaviour ...
      end
    end

`BaseInstance` carries everything shared with Services. This fragment carries
only what is resource-specific.

## Resource state

Two layers, both ITU-grounded:

- **`lifecycle_state`** — the resource lifecycle, from ITU-T M.3701. TMF639 v4
  omitted a lifecycle field, so this began as a near-universal customization;
  **TMF639 v5 standardised it as `lifecycleState`** (the wire key emitted here)
  with values `planned` / `installed` / `pendingRemoval` — the resting-state
  (milestone) form: you reach `planned` by *finishing* planning. `nil` is both the
  initial and the removed/terminal state (no explicit cancelled/terminated). For a
  resource, `installed` is the equivalent of a service "operating" — present and
  usable, just not as actively stateful as a service.
- **`administrative_state` / `operational_state` / `usage_state` /
  `resource_status`** — the TMF639 v4 status attributes from the ITU-T X.731 /
  M.3100 state-management model. They are **orthogonal** — any axis moves
  independently — so they are plain enums, not a state machine. (v5 decomposes the
  single `resource_status` into alarm/availability/procedural/control/standby
  status; `resource_status` is kept `allow_nil?` as a v4 back-compat escape hatch.)

`lifecycle_state` is a genuine ordered lifecycle and is the natural candidate for
an `AshStateMachine` (symmetric with `Service.state`) — deferred to #189 so its
transition rules land with the other state machines, and to avoid widening
ash_neo4j#284 across Resource leaves before that upstream fix.

# `extensions`

# `opts`

# `persisted`

# `spark_dsl_config`

# `validate_sections`

---

*Consult [api-reference.md](api-reference.md) for complete listing*