Defined in: async-throttler.ts:230

A class that creates an async throttled function.

Async vs Sync Versions: The async version provides advanced features over the sync Throttler:

• Returns promises that can be awaited for throttled function results
• Built-in retry support via AsyncRetryer integration
• Abort support to cancel in-flight executions
• Cancel support to prevent pending executions from starting
• Comprehensive error handling with onError callbacks and throwOnError control
• Detailed execution tracking (success/error/settle counts)
• Waits for ongoing executions to complete before scheduling the next one

The sync Throttler is lighter weight and simpler when you don't need async features, return values, or execution control.

What is Throttling? Throttling limits how often a function can be executed, allowing only one execution within a specified time window. Unlike debouncing which resets the delay timer on each call, throttling ensures the function executes at a regular interval regardless of how often it's called.

This is useful for rate-limiting API calls, handling scroll/resize events, or any scenario where you want to ensure a maximum execution frequency.

Error Handling:

• If an onError handler is provided, it will be called with the error and throttler instance
• If throwOnError is true (default when no onError handler is provided), the error will be thrown
• If throwOnError is false (default when onError handler is provided), the error will be swallowed
• Both onError and throwOnError can be used together - the handler will be called before any error is thrown
• The error state can be checked using the underlying AsyncThrottler instance

State Management:

• Uses TanStack Store for reactive state management
• Use initialState to provide initial state values when creating the async throttler
• Use onSuccess callback to react to successful function execution and implement custom logic
• Use onError callback to react to function execution errors and implement custom error handling
• Use onSettled callback to react to function execution completion (success or error) and implement custom logic
• The state includes error count, execution status, last execution time, and success/settle counts
• State can be accessed via asyncThrottler.store.state when using the class directly
• When using framework adapters (React/Solid), state is accessed from asyncThrottler.state

const throttler = new AsyncThrottler(async (value: string) => {
  const result = await saveToAPI(value);
  return result; // Return value is preserved
}, {
  wait: 1000,
  onError: (error) => {
    console.error('API call failed:', error);
  }
});

// Will only execute once per second no matter how often called
// Returns the API response directly
const result = await throttler.maybeExecute(inputElement.value);

const throttler = new AsyncThrottler(async (value: string) => {
  const result = await saveToAPI(value);
  return result; // Return value is preserved
}, {
  wait: 1000,
  onError: (error) => {
    console.error('API call failed:', error);
  }
});

// Will only execute once per second no matter how often called
// Returns the API response directly
const result = await throttler.maybeExecute(inputElement.value);

• TFn extends AnyAsyncFunction

new AsyncThrottler<TFn>(fn, initialOptions): AsyncThrottler<TFn>

new AsyncThrottler<TFn>(fn, initialOptions): AsyncThrottler<TFn>

Defined in: async-throttler.ts:242

TFn

AsyncThrottlerOptions<TFn>

AsyncThrottler<TFn>

asyncRetryers: Map<number, AsyncRetryer<TFn>>;

asyncRetryers: Map<number, AsyncRetryer<TFn>>;

Defined in: async-throttler.ts:236

fn: TFn;

fn: TFn;

Defined in: async-throttler.ts:243

key: string;

key: string;

Defined in: async-throttler.ts:234

options: AsyncThrottlerOptions<TFn>;

options: AsyncThrottlerOptions<TFn>;

Defined in: async-throttler.ts:235

readonly store: Store<Readonly<AsyncThrottlerState<TFn>>>;

readonly store: Store<Readonly<AsyncThrottlerState<TFn>>>;

Defined in: async-throttler.ts:231

_emit(): void

_emit(): void

Defined in: async-throttler.ts:264

Emits a change event for the async throttler instance. Mostly useful for devtools.

void

abort(): void

abort(): void

Defined in: async-throttler.ts:532

Aborts all ongoing executions with the internal abort controllers. Does NOT cancel any pending execution that have not started yet.

void

cancel(): void

cancel(): void

Defined in: async-throttler.ts:542

Cancels any pending execution that have not started yet. Does NOT abort any execution already in progress.

void

flush(): Promise<undefined | ReturnType<TFn>>

flush(): Promise<undefined | ReturnType<TFn>>

Defined in: async-throttler.ts:461

Processes the current pending execution immediately

Promise<undefined | ReturnType<TFn>>

getAbortSignal(maybeExecuteCount?): null | AbortSignal

getAbortSignal(maybeExecuteCount?): null | AbortSignal

Defined in: async-throttler.ts:522

Returns the AbortSignal for a specific execution. If no maybeExecuteCount is provided, returns the signal for the most recent execution. Returns null if no execution is found or not currently executing.

number

Optional specific execution to get signal for

null | AbortSignal

const throttler = new AsyncThrottler(
  async (data: string) => {
    const signal = throttler.getAbortSignal()
    if (signal) {
      const response = await fetch('/api/save', {
        method: 'POST',
        body: data,
        signal
      })
      return response.json()
    }
  },
  { wait: 1000 }
)

const throttler = new AsyncThrottler(
  async (data: string) => {
    const signal = throttler.getAbortSignal()
    if (signal) {
      const response = await fetch('/api/save', {
        method: 'POST',
        body: data,
        signal
      })
      return response.json()
    }
  },
  { wait: 1000 }
)

maybeExecute(...args): Promise<undefined | ReturnType<TFn>>

maybeExecute(...args): Promise<undefined | ReturnType<TFn>>

Defined in: async-throttler.ts:337

Attempts to execute the throttled function. The execution behavior depends on the throttler options:

• If enough time has passed since the last execution (>= wait period):

  • With leading=true: Executes immediately
  • With leading=false: Waits for the next trailing execution

• If within the wait period:

  • With trailing=true: Schedules execution for end of wait period
  • With trailing=false: Drops the execution

...Parameters<TFn>

Promise<undefined | ReturnType<TFn>>

const throttled = new AsyncThrottler(fn, { wait: 1000 });

// First call executes immediately
await throttled.maybeExecute('a', 'b');

// Call during wait period - gets throttled
await throttled.maybeExecute('c', 'd');

const throttled = new AsyncThrottler(fn, { wait: 1000 });

// First call executes immediately
await throttled.maybeExecute('a', 'b');

// Call during wait period - gets throttled
await throttled.maybeExecute('c', 'd');

reset(): void

reset(): void

Defined in: async-throttler.ts:556

Resets the debouncer state to its default values

void

setOptions(newOptions): void

setOptions(newOptions): void

Defined in: async-throttler.ts:269

Updates the async throttler options

Partial<AsyncThrottlerOptions<TFn>>

void