Handling websocket connections

The way Zibri handles websocket connections is pretty similar to http. It also supports recovering and replaying a prior connection.

Establishing a connection

By default, the websocket service accepts all connection attempts. You can override this behaviour by providing the following in your providers array:

// ...
[ZIBRI_DI_TOKENS.WEBSOCKET_OPTIONS]: {
    useFactory: () => ({ 
        timeoutInMs: Ms.SECOND * 5,
        isAllowedToConnect: () => false
    })
}
// ...
Copy

Receiving messages

For handling incomig websocket messages, you need to create a websocket controller:

// src/controllers/test.websocket-controller.ts
import { WebsocketController, WebsocketBody, WebsocketRoute, Property, BaseWebsocketConnection, CurrentWebsocketConnection } from 'zibri';

class Test {
    @Property.string()
    value!: string;
}

@WebsocketController()
export class TestWebsocketController {

    @WebsocketRoute('chat message')
    async receiveChatMessage(
        @WebsocketBody(Test)
        message: Test,
        @CurrentWebsocketConnection()
        connection: BaseWebsocketConnection
    ): Promise<void> {
        // ...
    }
}
Copy

As you can see it is basically exactly the same as a "normal" controller. With all the parsing/validation etc. builtin.

Sending messages

Messages can be send by using the websocket service. It provides methods for:

• sending to a specific connection
• sending to all connections
• sending to a channel

import { WebsocketController, WebsocketBody, WebsocketRoute, Property, Inject, ZIBRI_DI_TOKENS, WebsocketService, BaseWebsocketConnection, CurrentWebsocketConnection } from 'zibri';

export class CreateWebsocketChatMessageDTO {
    @Property.string()
    message!: string;
}

@WebsocketController()
export class TestWebsocketController {
    constructor(
        @Inject(ZIBRI_DI_TOKENS.WEBSOCKET_SERVICE)
        private readonly websocketService: WebsocketService
    ) {}

    @WebsocketRoute('chat message')
    async receiveChatMessage(
        @WebsocketBody(CreateWebsocketChatMessageDTO)
        message: CreateWebsocketChatMessageDTO,
        @CurrentWebsocketConnection()
        connection: BaseWebsocketConnection
    ): Promise<void> {
        await this.websocketService.sendToAll({
            event: 'chat message',
            message: {
                ok: true,
                data: message,
                senderUserId: connection.userId,
                senderConnectionId: connection.id
            }
        });
    }
}
Copy

Handling channels

Channels are created by using a repository with the WebsocketChannel entity. See accessing a data source for more information.

A websocket connection can join or leave them by using the respective methods on the websocket service. This will also be completely restored when connecting again in the future.