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Events and Subscriptions

Receive real-time notifications when nodes are discovered on the local network or when their state changes.

info

For unified updates with channel priority (SDK v2.2.2+), see Subscription Channels.

note

The userInstance refers to ESPRMUser from User Sign in.

What This Module Does ?​

Register callbacks to keep your app in sync with devices:

  • localDiscovery — node reachable on the local network; use with Transport Order for local-first control
  • nodeUpdates — parameter or connectivity changes; requires notification adapter

Use Subscription Channels instead for multi-source updates (push, MQTT, custom) with channel priority.

Expected outcome: Callbacks run when nodes are discovered locally or state changes remotely.

Common Workflows​

Subscribe to discovery and updates​

import { ESPRMEventType } from "@espressif/rainmaker-base-sdk";

userInstance.subscribe(ESPRMEventType.localDiscovery, ({ nodeId, transportDetails }) => {
  updateNodeTransport(nodeId, transportDetails);
});

userInstance.subscribe(ESPRMEventType.nodeUpdates, (updateData) => {
  refreshNodeInUI(updateData);
});

Enable local transport via discovery​

userInstance.subscribe(ESPRMEventType.localDiscovery, ({ nodeId, transportDetails }) => {
  const node = findNodeById(nodeId);
  if (node) {
    node.availableTransports = node.availableTransports || {};
    node.availableTransports[transportDetails.type] = transportDetails;
  }
});

Pair with Transport Order.

Setup with transport priority​

import { ESPRMBase, ESPRMEventType, ESPTransportMode } from "@espressif/rainmaker-base-sdk";

ESPRMBase.setTransportOrder([ESPTransportMode.local, ESPTransportMode.cloud]);
userInstance.subscribe(ESPRMEventType.localDiscovery, handleLocalDiscovery);
userInstance.subscribe(ESPRMEventType.nodeUpdates, handleNodeUpdates);

Manage subscriptions​

userInstance.subscribe(ESPRMEventType.localDiscovery, [callback1, callback2]);
userInstance.unsubscribe(ESPRMEventType.localDiscovery, callback1);
userInstance.removeAllCallbacks(ESPRMEventType.localDiscovery);

Error Handling​

const handleNodeUpdates = (updateData) => {
  try {
    updateStore(updateData);
  } catch (error) {
    console.error("Failed to process node update:", error);
  }
};

Keep callbacks lightweight.

Advanced Concepts​

Mental model​

Subscribe once → get notified when things change.

Local discovery flow​

Transport + discovery​

Discovery fills availableTransports; transport order selects the route for setValue(). Both are required for local-first control.

Best Practices​

  1. Subscribe before actions that expect updates
  2. Keep callbacks lightweight
  3. Remove callbacks on unmount
  4. Configure required adapters
  5. Test on-network and remote

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