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📄 createEventHook

📊 Analysis Summary

Metric	Count
🔧 Functions	6
📦 Imports	2
⚡ Async/Await Patterns	2
📐 Interfaces	1
📑 Type Aliases	5

📚 Table of Contents

• Imports
• Async/Await Patterns
• Functions
• Interfaces
• Type Aliases

🛠️ File Location:

📂 packages/shared/createEventHook/index.ts

📦 Imports

Name	Source
IsAny	../utils/types
tryOnScopeDispose	../tryOnScopeDispose

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Async/Await Patterns

Type	Function	Await Expressions	Promise Chains
promise-chain	createEventHook	none	Promise.all
promise-chain	trigger	none	Promise.all

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Functions

createEventHook(): EventHookReturn<T>

Utility for creating event hooks

See: https://vueuse.org/createEventHook

Tags: @__NO_SIDE_EFFECTS__

Raw JSDoc

/**
 * Utility for creating event hooks
 *
 * @see https://vueuse.org/createEventHook
 *
 * @__NO_SIDE_EFFECTS__
 */

Calls:

• fns.delete
• fns.clear
• fns.add
• off
• tryOnScopeDispose (from ../tryOnScopeDispose)
• Promise.all
• Array.from(fns).map
• fn

Code

export function createEventHook<T = any>(): EventHookReturn<T> {
  const fns: Set<Callback<T>> = new Set()

  const off = (fn: Callback<T>) => {
    fns.delete(fn)
  }

  const clear = () => {
    fns.clear()
  }

  const on = (fn: Callback<T>) => {
    fns.add(fn)
    const offFn = () => off(fn)

    tryOnScopeDispose(offFn)

    return {
      off: offFn,
    }
  }

  const trigger: EventHookTrigger<T> = (...args) => {
    return Promise.all(Array.from(fns).map(fn => fn(...args)))
  }

  return {
    on,
    off,
    trigger,
    clear,
  }
}

Internal helpers

Declared inside another function in this file.

off(fn: Callback<T>): void

Parameters:

• fn Callback<T>

Returns: void

Calls:

• fns.delete

Code

(fn: Callback<T>) => {
    fns.delete(fn)
  }

clear(): void

Returns: void

Calls:

• fns.clear

Code

() => {
    fns.clear()
  }

on(fn: Callback<T>): { off: () => void; }

Parameters:

• fn Callback<T>

Returns: { off: () => void; }

Calls:

• fns.add
• off
• tryOnScopeDispose (from ../tryOnScopeDispose)

Code

(fn: Callback<T>) => {
    fns.add(fn)
    const offFn = () => off(fn)

    tryOnScopeDispose(offFn)

    return {
      off: offFn,
    }
  }

offFn(): void

Returns: void

Calls:

• off

Code

() => off(fn)

trigger(args: Parameters<Callback<T>>): Promise<void[]>

Parameters:

• args Parameters<Callback<T>>

Returns: Promise<void[]>

Calls:

• Promise.all
• Array.from(fns).map
• fn

Code

(...args) => {
    return Promise.all(Array.from(fns).map(fn => fn(...args)))
  }

---

Interfaces

EventHook<T = any>

Interface Code

export interface EventHook<T = any> {
  on: EventHookOn<T>
  off: EventHookOff<T>
  trigger: EventHookTrigger<T>
  clear: () => void
}

Properties

Name	Type	Optional	Description
on	EventHookOn<T>	✗	not shown
off	EventHookOff<T>	✗	not shown
trigger	EventHookTrigger<T>	✗	not shown
clear	() => void	✗	not shown

---

Type Aliases

Callback<T>

type Callback<T> = IsAny<T> extends true
  ? (...param: any) => void
  : (
      [T] extends [void]
        ? (...param: unknown[]) => void
        : [T] extends [any[]]
            ? (...param: T) => void
            : (...param: [T, ...unknown[]]) => void
    );

EventHookOn<T = any>

type EventHookOn<T = any> = (fn: Callback<T>) => { off: () => void };

EventHookOff<T = any>

type EventHookOff<T = any> = (fn: Callback<T>) => void;

EventHookTrigger<T = any>

type EventHookTrigger<T = any> = (...param: Parameters<Callback<T>>) => Promise<unknown[]>;

EventHookReturn<T>

type EventHookReturn<T> = EventHook<T>;

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