Websocket notifications (API → Admin)

TL;DR

On the API, inject WebsocketsSendToIdentityUseCase (webiny/api) + IdentityContext (webiny/api/security) and call sendToIdentity.execute({ id }, { action, data }). On the Admin, implement a WebsocketEventHandler (webiny/admin/websockets) that filters on action and reacts (e.g. toast via Notifications from webiny/admin), registered with createFeature + RegisterFeature.

API, emit

import { WebsocketsSendToIdentityUseCase } from "webiny/api";
import { IdentityContext } from "webiny/api/security";

class MyTaskOrHook {
  constructor(
    private identityContext: IdentityContext.Interface,
    private sendToIdentity: WebsocketsSendToIdentityUseCase.Interface
  ) {}

  async notify(entry) {
    // Best-effort: a websocket failure must never fail the real work.
    try {
      const identity = this.identityContext.getIdentity();
      if (identity) {
        await this.sendToIdentity.execute(
          { id: identity.id },
          {
            action: "cms.product.discountApplied",
            data: { id: entry.entryId, price: entry.values.price }
          }
        );
      }
    } catch (ex) {
      // log & swallow
    }
  }
}
// dependencies: [IdentityContext, WebsocketsSendToIdentityUseCase]

• Send to the user who triggered the work, get them from IdentityContext. In a background task/bulk action, the triggering identity is available.
• Use a namespaced action string; put the payload in data.
• Sender data type: { action?: string; data?: T; error?: {...} }.

Admin, listen

import { WebsocketEventHandler } from "webiny/admin/websockets";
import { Notifications } from "webiny/admin";

const ACTION = "cms.product.discountApplied";

class MyHandlerImpl implements WebsocketEventHandler.Interface {
  constructor(private notifications: Notifications.Interface) {}