Skip to main content

Class: StatusUpdateManager

Defined in: src/stores/sites/utils/statusUpdateHandler.ts:125

Manages status update subscriptions and event handling with efficient incremental updates.

Remarks​

Provides a centralized manager for subscribing to and handling real-time status updates from the backend. Handles IPC event management and cleanup automatically. Prioritizes incremental updates over full syncs for better performance.

Example​

const manager = new StatusUpdateManager({
    fullResyncSites: () => syncSites(),
    getSites: () => store.getSites(),
    setSites: (sites) => store.setSites(sites),
});

manager.subscribe();

Constructors​

Constructor​

new StatusUpdateManager(options: StatusUpdateHandlerOptions): StatusUpdateManager;

Defined in: src/stores/sites/utils/statusUpdateHandler.ts:505

Constructs a new StatusUpdateManager instance.

Parameters​

options​

StatusUpdateHandlerOptions

Configuration options for the status update manager

Returns​

StatusUpdateManager

Remarks​

Initializes the manager with the required dependencies for status update handling. Does not start listening for events until subscribe() is called.

Properties​

EXPECTED_LISTENER_COUNT​

readonly static EXPECTED_LISTENER_COUNT: number = STATUS_UPDATE_LISTENER_COUNT;

Defined in: src/stores/sites/utils/statusUpdateHandler.ts:127

Number of listeners required for a healthy subscription.

cleanupFunctions​

private cleanupFunctions: () => void[] = [];

Defined in: src/stores/sites/utils/statusUpdateHandler.ts:140

Internal

Array of cleanup functions for active event listeners.

Returns​

void

Remarks​

Stores cleanup functions returned by IPC event listeners. These are called during unsubscribe() to properly remove event listeners and prevent memory leaks. Each function removes a specific event listener.

fullResyncSites​

private readonly fullResyncSites: () => Promise<void>;

Defined in: src/stores/sites/utils/statusUpdateHandler.ts:152

Internal

Function to trigger full site data sync from backend.

Returns​

Promise<void>

Remarks​

Callback function provided during construction that performs a complete refresh of site data from the backend. Used as fallback when incremental updates fail or when a full sync is required.

getSites​

private readonly getSites: () => Site[];

Defined in: src/stores/sites/utils/statusUpdateHandler.ts:164

Internal

Function to get current sites from store.

Returns​

Site[]

Remarks​

Callback function that returns the current array of sites from the store state. Used to access current data when applying incremental status updates.

isListenerAttached​

private isListenerAttached: boolean = false;

Defined in: src/stores/sites/utils/statusUpdateHandler.ts:176

Internal

Flag tracking whether event listener is currently attached.

Remarks​

Boolean flag that tracks the subscription state. True when IPC event listeners are active and receiving status updates. Used to prevent duplicate subscriptions and to provide subscription status.

subscriptionGeneration​

private subscriptionGeneration: number = 0;

Defined in: src/stores/sites/utils/statusUpdateHandler.ts:179

Monotonic token used to invalidate asynchronous subscription setup.

onUpdate​

private readonly onUpdate:
  | ((update: StatusUpdate) => void)
  | undefined;

Defined in: src/stores/sites/utils/statusUpdateHandler.ts:191

Internal

Optional callback for status update notifications.

Remarks​

Optional callback function that is invoked when a status update is successfully applied. Receives the StatusUpdate object with details about the change. Can be used for logging or triggering side effects.

setSites​

private readonly setSites: (sites: Site[]) => void;

Defined in: src/stores/sites/utils/statusUpdateHandler.ts:203

Internal

Function to update sites in the store.

Parameters​

sites​

Site[]

Returns​

void

Remarks​

Callback function that updates the store with a new array of sites. Used to apply incremental status updates and full sync results to the store state.

Methods​

handleIncrementalStatusUpdate()​

private handleIncrementalStatusUpdate(event: MonitorStatusChangedEvent): Promise<void>;

Defined in: src/stores/sites/utils/statusUpdateHandler.ts:217

Internal

Handle incremental status updates efficiently using complete event data.

Parameters​

event​

MonitorStatusChangedEvent

Monitor status changed event with complete data

Returns​

Promise<void>

Remarks​

Applies status changes using the complete monitor and site objects from the backend event. This preserves the updated history and ensures check counts increment correctly while providing real-time updates.

attemptFullResync()​

private attemptFullResync(reason: string): Promise<void>;

Defined in: src/stores/sites/utils/statusUpdateHandler.ts:274

Attempts a full resync and guarantees the caller never throws.

Parameters​

reason​

string

Returns​

Promise<void>

subscribe()​

subscribe(): Promise<StatusUpdateSubscriptionResult>;

Defined in: src/stores/sites/utils/statusUpdateHandler.ts:302

Subscribe to status updates from the backend with efficient incremental processing.

Returns​

Promise<StatusUpdateSubscriptionResult>

Remarks​

Sets up IPC event listeners for monitor status changes and monitoring lifecycle events. Automatically performs an initial full sync when subscribing. Prioritizes incremental updates over full syncs for better performance.

Example​

manager.subscribe();

processStatusUpdateCandidate()​

private processStatusUpdateCandidate(candidate: unknown, source: string): Promise<void>;

Defined in: src/stores/sites/utils/statusUpdateHandler.ts:425

Process an unknown candidate payload that may represent an enriched monitor status change.

Parameters​

candidate​

unknown

source​

string

Returns​

Promise<void>

Remarks​

This method centralizes:

  • Type guard checks
  • Development diagnostics
  • Fallback to full resync when payloads are incomplete
  • Error containment so listener callbacks never throw

startStatusUpdateProcessing()​

private startStatusUpdateProcessing(candidate: unknown, source: string): void;

Defined in: src/stores/sites/utils/statusUpdateHandler.ts:460

Parameters​

candidate​

unknown

source​

string

Returns​

void

recordSubscriptionError()​

private recordSubscriptionError(
   errors: string[],
   scope: string,
   error: unknown): Error;

Defined in: src/stores/sites/utils/statusUpdateHandler.ts:485

Records a subscription-related error in a consistent format.

Parameters​

errors​

string[]

scope​

string

error​

unknown

Returns​

Error

Remarks​

The returned error instance is the normalized Error so callers can reuse it for structured logging.

getExpectedListenerCount()​

getExpectedListenerCount(): number;

Defined in: src/stores/sites/utils/statusUpdateHandler.ts:517

Retrieves the expected listener count for diagnostics.

Returns​

number

Number of listeners the manager attempts to attach.

isSubscribed()​

isSubscribed(): boolean;

Defined in: src/stores/sites/utils/statusUpdateHandler.ts:529

Check if currently subscribed to status updates.

Returns​

boolean

True if subscribed and listening for events, false otherwise

Remarks​

Returns true when event listeners are active.

unsubscribe()​

unsubscribe(): void;

Defined in: src/stores/sites/utils/statusUpdateHandler.ts:551

Unsubscribe from all status update events.

Returns​

void

Remarks​

Cleans up all IPC event listeners and resets internal state. Safe to call multiple times - will not throw if already unsubscribed.

Example​

import { logger } from "@app/services/logger";

manager.unsubscribe();
logger.info("Subscription active?", {
    isSubscribed: manager.isSubscribed(),
}); // false

cleanupListeners()​

private cleanupListeners(cleanupFunctions: readonly () => void[]): void;

Defined in: src/stores/sites/utils/statusUpdateHandler.ts:564

Parameters​

cleanupFunctions​

readonly () => void[]

Returns​

void

getCurrentSubscriptionResult()​

private getCurrentSubscriptionResult(listenerDescriptors: readonly StatusUpdateListenerDescriptor[]): StatusUpdateSubscriptionResult;

Defined in: src/stores/sites/utils/statusUpdateHandler.ts:577

Parameters​

listenerDescriptors​

readonly StatusUpdateListenerDescriptor[]

Returns​

StatusUpdateSubscriptionResult

handleMonitoringLifecycleEvent()​

Call Signature​

private handleMonitoringLifecycleEvent(phase: "started", event: MonitoringStartedEventData): void;

Defined in: src/stores/sites/utils/statusUpdateHandler.ts:599

Parameters​
phase​

"started"

event​

MonitoringStartedEventData

Returns​

void

Call Signature​

private handleMonitoringLifecycleEvent(phase: "stopped", event: MonitoringStoppedEventData): void;

Defined in: src/stores/sites/utils/statusUpdateHandler.ts:604

Parameters​
phase​

"stopped"

event​

MonitoringStoppedEventData

Returns​

void

applyMonitorStatusUpdate()​

private applyMonitorStatusUpdate(sites: Site[], event: MonitorStatusChangedEvent): Site[];

Defined in: src/stores/sites/utils/statusUpdateHandler.ts:639

Internal

Apply monitor status update using smart merging of fresh monitor data.

Parameters​

sites​

Site[]

Current sites array

event​

MonitorStatusChangedEvent

Status change event with fresh monitor data

Returns​

Site[]

Updated sites array

Remarks​

Uses the fresh monitor object from the backend event to update the specific monitor while preserving the existing site structure and other monitors. This ensures updated history and response times are applied without losing site-level context.

isMonitorStatusChangedEvent()​

private isMonitorStatusChangedEvent(data: unknown): data is MonitorStatusChangedEvent;

Defined in: src/stores/sites/utils/statusUpdateHandler.ts:661

Internal

Type guard to validate incoming data as complete MonitorStatusChangedEvent.

Parameters​

data​

unknown

Unknown data from IPC events

Returns​

data is MonitorStatusChangedEvent

True if data conforms to MonitorStatusChangedEvent interface

Remarks​

Performs structural validation to ensure the data has the expected shape for incremental processing with complete monitor and site objects. This helps prevent runtime errors from malformed data.