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📄 index.ts

📊 Analysis Summary

Metric	Count
🔧 Functions	3
📦 Imports	4
📊 Variables & Constants	1
📑 Type Aliases	1

📚 Table of Contents

• Imports
• Variables & Constants
• Functions
• Type Aliases

🛠️ File Location:

📂 packages/core/usePerformanceObserver/index.ts

📦 Imports

Name	Source
ConfigurableWindow	../_configurable
tryOnScopeDispose	@vueuse/shared
defaultWindow	../_configurable
useSupported	../useSupported

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Variables & Constants

Name	Type	Kind	Value	Exported
observer	PerformanceObserver | undefined	let/var	*not shown*	✗

---

Functions

usePerformanceObserver(options: UsePerformanceObserverOptions, callback: PerformanceObserverCallback): { isSupported: any; start: () => void; stop: () => void; }

Code

export function usePerformanceObserver(options: UsePerformanceObserverOptions, callback: PerformanceObserverCallback) {
  const {
    window = defaultWindow,
    immediate = true,
    ...performanceOptions
  } = options

  const isSupported = useSupported(() => window && 'PerformanceObserver' in window)

  let observer: PerformanceObserver | undefined

  const stop = () => {
    observer?.disconnect()
  }

  const start = () => {
    if (isSupported.value) {
      stop()
      observer = new PerformanceObserver(callback)
      observer.observe(performanceOptions)
    }
  }

  tryOnScopeDispose(stop)

  if (immediate)
    start()

  return {
    isSupported,
    start,
    stop,
  }
}

• JSDoc:

  /**
   * Observe performance metrics.
   *
   * @see https://vueuse.org/usePerformanceObserver
   * @param options
   */
  

• Parameters:

• options: UsePerformanceObserverOptions
• callback: PerformanceObserverCallback
• Return Type: { isSupported: any; start: () => void; stop: () => void; }
• Calls:
• useSupported (from ../useSupported)
• observer?.disconnect
• stop
• observer.observe
• tryOnScopeDispose (from @vueuse/shared)
• start

stop(): void

Code

() => {
    observer?.disconnect()
  }

• Return Type: void
• Calls:
• observer?.disconnect

start(): void

Code

() => {
    if (isSupported.value) {
      stop()
      observer = new PerformanceObserver(callback)
      observer.observe(performanceOptions)
    }
  }

• Return Type: void
• Calls:
• stop
• observer.observe

---

Type Aliases

UsePerformanceObserverOptions

type UsePerformanceObserverOptions = PerformanceObserverInit & ConfigurableWindow & {
  /**
   * Start the observer immediate.
   *
   * @default true
   */
  immediate?: boolean
};

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