@deltares/fews-web-oc-composables

---

@deltares/fews-web-oc-composables / useRefreshCoordinator

Function: useRefreshCoordinator()

useRefreshCoordinator(callback, options): RefreshCoordinator

Defined in: useRefreshCoordinator/index.ts:131

Beta

Coordinates automatic refreshes for data-fetching composables, driven by one or more RefreshPolicy triggers: a shared system tick, a fixed interval, document-visibility resume, or manual triggers.

Only one refresh runs at a time: if trigger() is called while a refresh is already in flight, a single refresh is queued to run immediately afterwards.

Parameters

callback

() => void | Promise<void>

The function to invoke on each refresh. May be async; while it is pending, further triggers are coalesced into one pending refresh.

options

UseRefreshCoordinatorOptions

Member	Type	Description
enabled?	Ref<boolean, boolean>	A reactive flag controlling whether automatic refreshes are currently enabled. When false, all triggers are ignored until it becomes true again.
immediateCallback?	boolean	Whether to invoke the callback immediately when the coordinator is created.
intervalMs?	number	The interval, in milliseconds, between automatic refreshes when 'onInterval' is included in policies.
policies	RefreshPolicy[]	The policies that can trigger a refresh. Only policies included here have any effect; e.g. 'onInterval' must be included for intervalMs to take effect.
systemTick?	Ref<Date | undefined, Date | undefined>	The system-time synchronization tick, used by the 'onSystemTick' policy. A refresh is triggered whenever this ref's value changes.

Configuration for which policies trigger a refresh, and their parameters. See UseRefreshCoordinatorOptions.

Returns

RefreshCoordinator

Member	Type	Description
isActive	Readonly<Ref<boolean>>	Whether automatic refreshes are currently active.
lastRefreshAt	Readonly<Ref<Date | undefined>>	The time at which the most recent refresh completed successfully.
lastTriggerPolicy	Readonly<Ref<RefreshPolicy | undefined>>	The policy that caused the most recent refresh.
pause	() => void	Pauses automatic refreshes.
resume	() => void	Resumes automatic refreshes.
trigger	(policy?: RefreshPolicy) => void	Requests a refresh. The refresh is ignored when the coordinator is paused or disabled.

A RefreshCoordinator used to pause/resume automatic refreshes, trigger a refresh manually, and inspect the last refresh.

Example

import { useRefreshCoordinator } from '@deltares/fews-web-oc-composables'

const coordinator = useRefreshCoordinator(
  async () => {
    await fetchLatestData()
  },
  {
    policies: ['onSystemTick', 'onInterval', 'onVisibilityResume'],
    intervalMs: 60_000,
    immediateCallback: true,
  },
)

// Trigger a refresh manually, e.g. from a "Refresh now" button:
coordinator.trigger()

// Temporarily stop automatic refreshes, e.g. while a dialog is open:
coordinator.pause()
coordinator.resume()