roboto.domain.triggers.namespace#

Module Contents#

roboto.domain.triggers.namespace.CHANGED_ROOT = 'changed'#

the metadata fields an update event put, keyed by field name.

Type:

Delta root

roboto.domain.triggers.namespace.ENVELOPE_ROOT = 'envelope'#

its id, source, subject, type, time, and org. Reserved: no event type may expose it as an entity root.

Type:

Namespace root served from the platform event’s own envelope

class roboto.domain.triggers.namespace.EventNamespace(event, source, *, trigger=None, _records=None)#

Resolves dotted variable paths against a platform event.

The one namespace with three consumers: condition evaluation (whole records via record()), target template substitution (single paths via resolve(), satisfying the VariableResolver protocol), and idempotency projections. Entity-backed roots hydrate through the NamespaceSource at most once each and are cached for the namespace’s lifetime — including None results. The envelope, changed, and tag roots are served from the event itself and never touch the source; trigger is served from the bound trigger (see bound_to()) and is otherwise absent.

Parameters:
bound_to(trigger)#

A view of this namespace for one trigger, in which trigger.* resolves.

One namespace is shared across every trigger evaluated for an event so each entity hydrates once; the trigger being evaluated is per-trigger state, so it lives on a view rather than on the shared object. The view delegates every other root to the same hydration cache – reading dataset.name through it and through the parent costs one fetch in total.

Parameters:

trigger (roboto.domain.triggers.record.TriggerRecord) – The trigger whose templates and condition are being evaluated.

Return type:

EventNamespace

get(path)#

Return the value at dotted path (e.g. dataset.metadata.vehicle_id), or None.

The first path segment names the root; the rest walk nested mappings. Any missing segment yields None.

Parameters:

path (str)

Return type:

Any

record(root)#

Return the whole record for namespace root, hydrating it at most once.

Parameters:

root (str) – Namespace root to fetch. envelope yields the envelope fields; changed yields the changeset’s put fields; tag yields {"added": [...], "removed": [...]}; any other root delegates to the cached NamespaceSource.

Returns:

The record as a mapping, or None when the source cannot resolve the root.

Return type:

Optional[Mapping[str, Any]]

resolve(name)#

Return the string form of the value at name for template substitution, or None.

Parameters:

name (str)

Return type:

Optional[str]

class roboto.domain.triggers.namespace.NamespaceSource#

Bases: Protocol

Lazily hydrates entity-backed namespace roots for an event.

record_for_root(root, event)#

Load the entity for namespace root as a JSON-able mapping.

Parameters:

  • root (str) – The namespace root to hydrate ("dataset", "file", "invocation", "event", …). Never a delta or reserved root: the namespace serves envelope, trigger, schedule, changed and tag itself.

  • event (roboto.domain.platform_events.PlatformEvent) – The event whose subject identifies the entity to load.

Returns:

The entity as a mapping, or None when event cannot resolve it (no such root for this event type, or the entity was deleted between emit and evaluation).

Return type:

Optional[Mapping[str, Any]]

roboto.domain.triggers.namespace.TAG_ROOT = 'tag'#

the tags an event added and removed.

Type:

Delta root

roboto.domain.triggers.namespace.TRIGGER_ROOT = 'trigger'#

Namespace root describing the trigger being evaluated. Reserved for the consumer; no event type may expose it as an entity root.

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