Closed-vocabulary event_type taxonomy describing what format an event is. Promotes the former eventType block attribute to a real, queryable taxonomy (data-machine-events#761).

Overview

eventType used to live only as a serialized block attribute inside post_content. It could not be queried, filtered, counted, or browsed — filtering meant a post_content LIKE full scan — and its only consumer was JSON-LD @type.

Event_Type_Taxonomy replaces that with a real taxonomy carrying a closed vocabulary:

• Every term maps to a Schema.org @type through the _schema_type term meta value.
• The AI can only pick from the vocabulary, and an AI-supplied value can never create a term.
• The block attribute becomes derived output, not input.

Location

inc/Core/Event_Type_Taxonomy.php

Taxonomy Registration

Because the taxonomy is public, FilterAbilities::get_taxonomies_with_counts() picks it up automatically — it appears in the calendar filter modal with cross-filtered counts, and in Taxonomy/Badges.php, with no calendar code changes.

Default vocabulary

Seeded from EventSchemaProvider::default_event_type_vocabulary(), which derives directly from the existing EventSchemaProvider::EVENT_TYPES const:

Event, MusicEvent, Festival, ComedyEvent, DanceEvent, TheaterEvent, SportsEvent, ExhibitionEvent

Each term is self-mapped: its _schema_type term meta equals its own name. Event is the declared default. Out of the box this gives a working, standards-correct 8-term taxonomy with no consumer configuration.

Seeding is idempotent and guarded by a hash of the resolved vocabulary stored in the data_machine_events_event_type_seeded option, so it only runs when the vocabulary actually changes.

Replacing the vocabulary

add_filter(
    'data_machine_events_event_type_vocabulary',
    function ( array $vocabulary ): array {
        return array(
            array( 'name' => 'Live Music', 'schema_type' => 'MusicEvent', 'default' => true ),
            array( 'name' => 'Comedy',     'schema_type' => 'ComedyEvent' ),
        );
    }
);

Accepted entry shapes:

• array( 'name' => ..., 'schema_type' => ..., 'slug' => ..., 'default' => ... ) — slug defaults to sanitize_title( name ); the first entry becomes the default when none is flagged.
• 'Term Name' => 'SchemaType' — name keyed to its Schema.org @type.

Consumers may express editorial event formats that have no Schema.org equivalent, as long as each entry still maps to a valid @type. Site-specific editorial vocabulary belongs in the consumer, never in this plugin (see #437 / #478); this repo declares Schema.org terms only.

Closed-vocabulary enforcement

Data Machine’s generic TaxonomyHandler creates unknown AI values by default. Two core hooks (DM 0.131.0) close that path:

datamachine_taxonomy_tool_parameter

Rewrites the AI tool schema for event_type:

• type becomes string (not an array of free-form terms) and items is removed — event_type is single-valued.
• enum is derived from the resolved vocabulary, so the AI is structurally unable to emit an outside value.
• The description names every allowed value and states that inventing one is forbidden.

datamachine_taxonomy_assign_value

Runs before processTerms() / findOrCreateTerm():

• A recognized value resolves to that vocabulary term’s existing ID.
• An unrecognized value logs a warning and resolves to the declared default term’s ID — it never reaches wp_insert_term().
• An empty value returns '', which DM treats as "skip assignment silently".

Because the enum is derived from the vocabulary and the assign filter is a second gate, slop is structurally impossible rather than prompt-dependent.

Schema.org @type derivation

EventSchemaProvider::generateSchemaOrg() resolves @type in this order:

1. The _schema_type meta on the event’s assigned event_type term (authoritative).
2. The legacy eventType block attribute, resolved through the vocabulary — so an out-of-vocabulary legacy value cannot leak into JSON-LD.
3. Event.

The block attribute written by EventBlockContentBuilder is likewise the resolved Schema.org @type, never an editorial label.

Key methods

register(): void

Registers the taxonomy, hooks the two enforcement filters, and seeds the vocabulary when it changed.

get_vocabulary(): array

Returns the resolved vocabulary as normalized entries (name, slug, schema_type, default).

get_vocabulary_names(): string[]

The term names exposed to the AI as the closed enum.

resolve_schema_type( mixed $value ): string

Resolves any value (term name, slug, Schema.org type, term ID, or single-element array) to the Schema.org @type it represents, or ''. This is the validation primitive that replaced the raw in_array( $value, EVENT_TYPES ) checks in EventUpdateAbilities and EventUpsertValidator.

is_valid_value( mixed $value ): bool

Whether a value belongs to the active vocabulary.

resolve_term_id( mixed $value, bool $fallback_to_default = true ): int

Resolves a value to an existing term ID. Never creates a term for unrecognized input: it either falls back to the default entry or returns 0.

get_schema_type_for_post( int $post_id ): string

Reads the Schema.org @type the event’s assigned term maps to.

seed_vocabulary( ?array $vocabulary = null ): array

Creates any missing vocabulary terms and (re)stamps their _schema_type. The only path in this class that may create a term.

Scope boundary

event_type describes event format only. It deliberately does not distinguish a duo on a coffee-shop patio from a headliner in a 2,500-cap room — that is a venue property (Extra-Chill/extrachill-events#801).