Class: EngineActions | engine - SvelteKit

Named, overridable actions for one engine. Actions are either JS closures you register or engine defaults (e.g. undo/redo), and either kind can override the other by reusing the id.

JS-registered actions run directly in JS, so on the web you get full fidelity: get hands back the raw function and run passes args/results by reference (non-serializable payloads like File/Blob work). The engine also keeps a JSON trampoline per action so defaults run natively and host actions stay reachable across the FFI — that path is JSON-only and async. Engine defaults you have not overridden are reachable only via run; get returns undefined.

Remarks#

Main-thread only. get is web-only; use run/has/list cross-platform.

Constructors#

Constructor#

EngineActions

Methods#

register()#

Type Parameters#

Type Parameter
`K` extends `never`

Parameters#

Parameter	Type	Description
`id`	`K`	The action id (e.g. `undo`). Reusing an engine default’s id overrides it.
`fn`	`EngineActionsRegistry`[`K`] extends (…`args`) => `any` ? `any`[`any`] : `EngineCustomActionFunction`	The action body (sync or async). On the web it runs directly with any JS values. Across the FFI args/results are JSON, so only serializable payloads work there.

Returns#

void

Call Signature#

register(id, fn): void;

Parameters#

Parameter	Type	Description
`id`	`string`	The action id (e.g. `undo`). Reusing an engine default’s id overrides it.
`fn`	`EngineCustomActionFunction`	The action body (sync or async). On the web it runs directly with any JS values. Across the FFI args/results are JSON, so only serializable payloads work there.

Returns#

void

Signatures#

register(id: K, fn: EngineActionsRegistry[K] extends (args: any[]) => any ? any[any] : EngineCustomActionFunction): void

register(id: string, fn: EngineCustomActionFunction): void

get()#

Get the raw registered function for an id so you can call it synchronously.

Returns the exact function you registered. Returns undefined for unknown ids and engine-default native actions (which have no JS function) — use run for those.

Type Parameters#

Type Parameter
`K` extends `never`

Parameters#

Parameter	Type
`id`	`K`

Returns#

EngineActionsRegistry[K]

Remarks#

Web-only.

Call Signature#

get(id): EngineCustomActionFunction;

Get the raw registered function for an id so you can call it synchronously.

Returns the exact function you registered. Returns undefined for unknown ids and engine-default native actions (which have no JS function) — use run for those.

Parameters#

Parameter	Type
`id`	`string`

Returns#

EngineCustomActionFunction

Remarks#

Web-only.

Signatures#

get(id: K): EngineActionsRegistry[K]

get(id: string): EngineCustomActionFunction

run()#

Run an action by id and return its result as a Promise.

JS-registered actions are called directly (args/result by reference). Engine defaults go across the FFI (JSON args/result).

Type Parameters#

Type Parameter
`K` extends `never`

Parameters#

Parameter	Type	Description
`id`	`K`	The action id.
…`args`	`EngineActionsRegistry`[`K`] extends (…`args`) => `any` ? `A` : `unknown`[]	Arguments forwarded to the action.

Returns#

Promise<EngineActionsRegistry[K] extends (…args) => R ? Awaited<R> : unknown>

The action’s result, or a rejection if the id is unknown or it threw.

Call Signature#

run<R>(id, ...args): Promise<R>;

Run an action by id and return its result as a Promise.

JS-registered actions are called directly (args/result by reference). Engine defaults go across the FFI (JSON args/result).

Type Parameters#

Type Parameter	Default type
`R`	`unknown`

Parameters#

Parameter	Type	Description
`id`	`string`	The action id.
…`args`	`unknown`[]	Arguments forwarded to the action.

Returns#

Promise<R>

The action’s result, or a rejection if the id is unknown or it threw.

Signatures#

run(id: K, args: EngineActionsRegistry[K] extends (args: A) => any ? A : unknown[]): Promise<EngineActionsRegistry[K] extends (args: any[]) => R ? Awaited<R> : unknown>

run(id: string, args: unknown[]): Promise<R>

has()#

Whether an action with this id is registered (host or engine default).

Parameters#

Parameter	Type
`id`	`string`

Returns#

boolean

Signature#

has(id: string): boolean

unregister()#

Remove a host action, or revert an overridden engine default to its built-in.

If you override an engine default (such as select or undo), unregistering the id restores the default rather than leaving it unhandled. A custom id you registered yourself is removed entirely. Returns false only when the id is unknown.

Parameters#

Parameter	Type
`id`	`string`

Returns#

boolean

Signature#

unregister(id: string): boolean

list()#

List registered actions, optionally filtered by a * glob matcher on the id.

Parameters#

Parameter	Type
`options?`	{ `matcher?`: `string`; }
`options.matcher?`	`string`

Returns#

EngineActionInfo[]

Signature#

list(options?: object): EngineActionInfo[]