watchControlled

Watcher with pause and resume controls to ignore source updates. Source updates do not trigger a paused watcher.

Usage

import { watchControlled } from '@8ctavio/vergil'

const source = ref(0)
const watcher = watchControlled(source, v => {
    console.log(`new value: ${v}`)
})

// Normally trigger watcher
source.value++ // 'new value: 1'

// Ignore updates by pausing watcher
watcher.pause()
// Does not trigger watcher
source.value++
watcher.resume()

// Ignore updates with callback
watcher.ignore(() => {
    // Does not trigger watcher
    source.value++
})

// Stop watcher
watcher.stop()

Definition

// Single watch source
function watchControlled<T>(
    source: WatchSource<T>,
    callback: WatchCallback<T>,
    options?: WatchOptions;
): WatchControlledHandle

// Multiple watch sources
function watchControlled<T>(
    source: WatchSource<T>[],
    callback: WatchCallback<T[]>,
    options?: WatchOptions;
): WatchControlledHandle

type WatchControlledHandle = {
    stop(): void;
    pause(): void;
    resume(): void;
    ignore(callback: () => void): void;
}

Parameters

Same as a regular watcher.

Return value

A controlled watcher handle object with the following methods:

• stop: Stops watcher.
• pause: Pauses watcher. Source updates do not trigger paused watchers.
• resume: Resumes watcher.
• ignore: Pauses watcher, runs provided callback, and resumes watcher.