API reference / @chanx-js/server / core / TopicOptions

Interface: TopicOptions<Pattern, User, State>

Defined in: packages/server/src/topic.ts:62

Options for topic().

Extends

• ErrorHooks<TopicContext<Pattern, User, Message, State>>

Type Parameters

Type Parameter	Default type
Pattern extends string	-
User	-
State	Record<never, never>

Properties

authorize?

optional authorize?: (subscription) => boolean | Promise<boolean>;

Defined in: packages/server/src/topic.ts:79

Decide whether this connection may subscribe.

Parameters

Parameter	Type
subscription	{ conn: Connection<string, User>; params: PathParams<Pattern>; state: State; topic: string; }
subscription.conn	Connection<string, User>
subscription.params	PathParams<Pattern>
subscription.state	State
subscription.topic	string

Returns

boolean | Promise<boolean>

---

description?

optional description?: string;

Defined in: packages/server/src/topic.ts:73

The AsyncAPI channel's description.

---

layer?

optional layer?: string;

Defined in: packages/server/src/topic.ts:75

The channel layer to publish on. Defaults to default.

---

name?

optional name?: string;

Defined in: packages/server/src/topic.ts:71

Name of the topic's channel layer group namespace: two servers sharing a layer must agree on it. Defaults to RoomTopic for room:{...}.

---

onEventError?

optional onEventError?: (error, event, ctx) => void | Promise<void>;

Defined in: packages/server/src/consumer.ts:172

An event handler threw. Default: log it; the client is told nothing.

Parameters

Parameter	Type
error	unknown
event	Message
ctx	TopicContext

Returns

void | Promise<void>

Inherited from

ErrorHooks.onEventError

---

onHandlerError?

optional onHandlerError?: (error, message, ctx) => void | Promise<void>;

Defined in: packages/server/src/consumer.ts:170

A message handler threw. Default: log it, and an error frame naming the action.

Parameters

Parameter	Type
error	unknown
message	Message
ctx	TopicContext

Returns

void | Promise<void>

Inherited from

ErrorHooks.onHandlerError

---

onSubscribe?

optional onSubscribe?: (ctx) => void | Promise<void>;

Defined in: packages/server/src/topic.ts:86

Once subscribed; what it sends is state, not a reply, so it carries no ref.

Parameters

Parameter	Type
ctx	TopicContext<Pattern, User, Message<string, unknown>, State>

Returns

void | Promise<void>

---

onUnsubscribe?

optional onUnsubscribe?: (ctx) => void | Promise<void>;

Defined in: packages/server/src/topic.ts:90

Before leaving, on unsubscribe and on disconnect.

Parameters

Parameter	Type
ctx	TopicContext<Pattern, User, Message<string, unknown>, State>

Returns

void | Promise<void>

---

onValidationError?

optional onValidationError?: (issues, ctx) => void | Promise<void>;

Defined in: packages/server/src/consumer.ts:168

A frame failed validation. Default: an error frame listing the issues.

Parameters

Parameter	Type
issues	ValidationIssue[]
ctx	TopicContext

Returns

void | Promise<void>

Inherited from

ErrorHooks.onValidationError

---

state?

optional state?: (subscription) => State;

Defined in: packages/server/src/topic.ts:77

Per-subscription state, available as ctx.state; built before authorize.

Parameters

Parameter	Type
subscription	Subscription<User>

Returns

State