MessageMappingProperties

Kind: Interface

Source: packages/websockets/gateway-metadata-explorer.ts

Part of: Websockets

MessageMappingProperties describes the metadata required to connect an incoming WebSocket message to a gateway handler method. It stores the message pattern, handler name, executable callback, and whether acknowledgment handling is performed manually by the handler.

Properties

Diagram

mermaid
graph LR
  Client[WebSocket Client] --> Message[Incoming Message]
  Message --> Mapping[MessageMappingProperties]
  Mapping --> Pattern[message]
  Mapping --> Handler[methodName]
  Mapping --> Callback[callback]
  Mapping --> Ack[isAckHandledManually]
  Callback --> Result[Observable or Promise Result]

Usage

ts
import { Observable, of } from 'rxjs';

interface MessageMappingProperties {
  message: any;
  methodName: string;
  callback: (...args: any[]) => Observable<any> | Promise<any>;
  isAckHandledManually: boolean;
}

const messageMapping: MessageMappingProperties = {
  message: 'chat:send',
  methodName: 'handleChatMessage',
  callback: async (client, payload) => {
    return {
      event: 'chat:received',
      data: {
        clientId: client.id,
        message: payload.message,
      },
    };
  },
  isAckHandledManually: false,
};

// Example callback invocation during message dispatch
messageMapping.callback({ id: 'client-1' }, { message: 'Hello' })
  .then((result) => console.log(result));

AI Coding Instructions

• Ensure callback always returns either an Observable or a Promise; wrap synchronous values with Promise.resolve() or of().
• Use message as the routing pattern that identifies which incoming WebSocket event should invoke the handler.
• Set isAckHandledManually to true only when the handler explicitly invokes the client acknowledgment callback.
• Preserve methodName for diagnostics, logging, and metadata exploration; it should match the associated gateway method name.
• Avoid assuming a specific message payload shape because message and callback arguments are intentionally typed as any.

Relationships

• IMPORTS → isFunction
• IMPORTS → isUndefined
• IMPORTS → MetadataScanner
• IMPORTS → ParamsMetadata
• IMPORTS → ContextUtils

Used by

2 references from 2 files. Each is a place in this repository where the symbol is actually used — go read one rather than trusting an example.

Imported by (2)

• IoAdapter — packages/platform-socket.io/adapters/io-adapter.ts:14
• WsAdapter — packages/platform-ws/adapters/ws-adapter.ts:39