Framework
Version
Debouncer API Reference
Throttler API Reference
Rate Limiter API Reference
Queue API Reference
Batcher API Reference

React Example: UseRateLimiterWithPersister

tsx
import { useEffect, useState } from 'react'
import ReactDOM from 'react-dom/client'
import { useRateLimiter } from '@tanstack/react-pacer/rate-limiter'
import { useStoragePersister } from '@tanstack/react-persister/storage-persister'
import type { RateLimiterState } from '@tanstack/react-pacer/rate-limiter'

function App1() {
  const [windowType, setWindowType] = useState<'fixed' | 'sliding'>('fixed')

  // Use your state management library of choice
  const [instantCount, setInstantCount] = useState(0) // not rate-limited
  const [limitedCount, setLimitedCount] = useState(0) // rate-limited

  const rateLimiterPersister = useStoragePersister<RateLimiterState>({
    key: 'my-rate-limiter',
    storage: localStorage,
    maxAge: 1000 * 60, // 1 minute
    buster: 'v1',
  })

  // Using useRateLimiter with a rate limit of 5 executions per 5 seconds
  const rateLimiter = useRateLimiter(
    setLimitedCount,
    {
      // enabled: () => instantCount > 2,
      limit: 5,
      window: 5000,
      windowType: windowType,
      onReject: (rateLimiter) =>
        console.log(
          'Rejected by rate limiter',
          rateLimiter.getMsUntilNextWindow(),
        ),
      // optional local storage persister to retain state on page refresh
      initialState: rateLimiterPersister.loadState(),
    },
    // Optional Selector function to pick the state you want to track and use
    (state) => state, // entire state subscription for persister - don't do this unless you need to
  )

  useEffect(() => {
    rateLimiterPersister.saveState(rateLimiter.state)
  }, [rateLimiter.state])

  function increment() {
    // this pattern helps avoid common bugs with stale closures and state
    setInstantCount((c) => {
      const newCount = c + 1 // common new value for both
      rateLimiter.maybeExecute(newCount) // rate-limited state update
      return newCount // instant state update
    })
  }

  return (
    <div>
      <h1>TanStack Pacer useRateLimiter Example 1 (with persister)</h1>
      <div style={{ display: 'grid', gap: '0.5rem', marginBottom: '1rem' }}>
        <label>
          <input
            type="radio"
            name="windowType"
            value="fixed"
            checked={windowType === 'fixed'}
            onChange={() => setWindowType('fixed')}
          />
          Fixed Window
        </label>
        <label>
          <input
            type="radio"
            name="windowType"
            value="sliding"
            checked={windowType === 'sliding'}
            onChange={() => setWindowType('sliding')}
          />
          Sliding Window
        </label>
      </div>
      <table>
        <tbody>
          <tr>
            <td>Execution Count:</td>
            <td>{rateLimiter.state.executionCount}</td>
          </tr>
          <tr>
            <td>Rejection Count:</td>
            <td>{rateLimiter.state.rejectionCount}</td>
          </tr>
          <tr>
            <td>Remaining in Window:</td>
            <td>{rateLimiter.getRemainingInWindow()}</td>
          </tr>
          <tr>
            <td>Ms Until Next Window:</td>
            <td>{rateLimiter.getMsUntilNextWindow()}</td>
          </tr>
          <tr>
            <td colSpan={2}>
              <hr />
            </td>
          </tr>
          <tr>
            <td>Instant Count:</td>
            <td>{instantCount}</td>
          </tr>
          <tr>
            <td>Rate Limited Count:</td>
            <td>{limitedCount}</td>
          </tr>
        </tbody>
      </table>
      <div>
        <button onClick={increment}>Increment</button>
        <button onClick={() => rateLimiter.reset()}>Reset</button>
      </div>
      <pre style={{ marginTop: '20px' }}>
        {JSON.stringify(rateLimiter.store.state, null, 2)}
      </pre>
    </div>
  )
}

function App2() {
  const [instantSearch, setInstantSearch] = useState('')
  const [limitedSearch, setLimitedSearch] = useState('')

  // Using useRateLimiter with a rate limit of 5 executions per 5 seconds
  const rateLimiter = useRateLimiter(
    setLimitedSearch,
    {
      enabled: instantSearch.length > 2, // optional, defaults to true
      limit: 5,
      window: 5000,
      // windowType: 'sliding', // default is 'fixed'
      onReject: (rateLimiter) =>
        console.log(
          'Rejected by rate limiter',
          rateLimiter.getMsUntilNextWindow(),
        ),
    },
    // Optional Selector function to pick the state you want to track and use
    (state) => ({
      executionCount: state.executionCount,
      rejectionCount: state.rejectionCount,
    }),
  )

  function handleSearchChange(e: React.ChangeEvent<HTMLInputElement>) {
    const newValue = e.target.value
    setInstantSearch(newValue)
    rateLimiter.maybeExecute(newValue)
  }

  return (
    <div>
      <h1>TanStack Pacer useRateLimiter Example 2</h1>
      <div>
        <input
          autoFocus
          type="search"
          value={instantSearch}
          onChange={handleSearchChange}
          placeholder="Type to search..."
          style={{ width: '100%' }}
        />
      </div>
      <table>
        <tbody>
          <tr>
            <td>Execution Count:</td>
            <td>{rateLimiter.state.executionCount}</td>
          </tr>
          <tr>
            <td>Rejection Count:</td>
            <td>{rateLimiter.state.rejectionCount}</td>
          </tr>
          <tr>
            <td>Remaining in Window:</td>
            <td>{rateLimiter.getRemainingInWindow()}</td>
          </tr>
          <tr>
            <td>Ms Until Next Window:</td>
            <td>{rateLimiter.getMsUntilNextWindow()}</td>
          </tr>
          <tr>
            <td colSpan={2}>
              <hr />
            </td>
          </tr>
          <tr>
            <td>Instant Search:</td>
          </tr>
          <tr>
            <td>Rate Limited Search:</td>
            <td>{limitedSearch}</td>
          </tr>
        </tbody>
      </table>
      <div>
        <button onClick={() => rateLimiter.reset()}>Reset</button>
      </div>
      <pre style={{ marginTop: '20px' }}>
        {JSON.stringify(rateLimiter.store.state, null, 2)}
      </pre>
    </div>
  )
}

function App3() {
  const [currentValue, setCurrentValue] = useState(50)
  const [limitedValue, setLimitedValue] = useState(50)
  const [instantExecutionCount, setInstantExecutionCount] = useState(0)

  // Using useRateLimiter with a rate limit of 5 executions per 5 seconds
  const rateLimiter = useRateLimiter(
    setLimitedValue,
    {
      limit: 20,
      window: 2000,
      onReject: (rateLimiter) =>
        console.log(
          'Rejected by rate limiter',
          rateLimiter.getMsUntilNextWindow(),
        ),
    },
    // Optional Selector function to pick the state you want to track and use
    (state) => ({
      executionCount: state.executionCount,
      rejectionCount: state.rejectionCount,
    }),
  )

  function handleRangeChange(e: React.ChangeEvent<HTMLInputElement>) {
    const newValue = parseInt(e.target.value, 10)
    setCurrentValue(newValue)
    setInstantExecutionCount((c) => c + 1)
    rateLimiter.maybeExecute(newValue)
  }

  return (
    <div>
      <h1>TanStack Pacer useRateLimiter Example 3</h1>
      <div style={{ marginBottom: '20px' }}>
        <label>
          Current Range:
          <input
            type="range"
            min="0"
            max="100"
            value={currentValue}
            onChange={handleRangeChange}
            style={{ width: '100%' }}
          />
          <span>{currentValue}</span>
        </label>
      </div>
      <div style={{ marginBottom: '20px' }}>
        <label>
          Rate Limited Range (Readonly):
          <input
            type="range"
            min="0"
            max="100"
            value={limitedValue}
            readOnly
            style={{ width: '100%' }}
          />
          <span>{limitedValue}</span>
        </label>
      </div>
      <table>
        <tbody>
          <tr>
            <td>Execution Count:</td>
            <td>{rateLimiter.state.executionCount}</td>
          </tr>
          <tr>
            <td>Rejection Count:</td>
            <td>{rateLimiter.state.rejectionCount}</td>
          </tr>
          <tr>
            <td>Remaining in Window:</td>
            <td>{rateLimiter.getRemainingInWindow()}</td>
          </tr>
          <tr>
            <td>Ms Until Next Window:</td>
            <td>{rateLimiter.getMsUntilNextWindow()}</td>
          </tr>
          <tr>
            <td>Instant Executions:</td>
            <td>{instantExecutionCount}</td>
          </tr>
          <tr>
            <td>Saved Executions:</td>
            <td>{instantExecutionCount - rateLimiter.state.executionCount}</td>
          </tr>
          <tr>
            <td>% Reduction:</td>
            <td>
              {instantExecutionCount === 0
                ? '0'
                : Math.round(
                    ((instantExecutionCount -
                      rateLimiter.state.executionCount) /
                      instantExecutionCount) *
                      100,
                  )}
              %
            </td>
          </tr>
        </tbody>
      </table>
      <div style={{ color: '#666', fontSize: '0.9em' }}>
        <p>Rate limited to 20 updates per 2 seconds</p>
      </div>
      <pre style={{ marginTop: '20px' }}>
        {JSON.stringify(rateLimiter.store.state, null, 2)}
      </pre>
    </div>
  )
}

const root = ReactDOM.createRoot(document.getElementById('root')!)
root.render(
  <div>
    <App1 />
    <hr />
    <App2 />
    <hr />
    <App3 />
  </div>,
)
import { useEffect, useState } from 'react'
import ReactDOM from 'react-dom/client'
import { useRateLimiter } from '@tanstack/react-pacer/rate-limiter'
import { useStoragePersister } from '@tanstack/react-persister/storage-persister'
import type { RateLimiterState } from '@tanstack/react-pacer/rate-limiter'

function App1() {
  const [windowType, setWindowType] = useState<'fixed' | 'sliding'>('fixed')

  // Use your state management library of choice
  const [instantCount, setInstantCount] = useState(0) // not rate-limited
  const [limitedCount, setLimitedCount] = useState(0) // rate-limited

  const rateLimiterPersister = useStoragePersister<RateLimiterState>({
    key: 'my-rate-limiter',
    storage: localStorage,
    maxAge: 1000 * 60, // 1 minute
    buster: 'v1',
  })

  // Using useRateLimiter with a rate limit of 5 executions per 5 seconds
  const rateLimiter = useRateLimiter(
    setLimitedCount,
    {
      // enabled: () => instantCount > 2,
      limit: 5,
      window: 5000,
      windowType: windowType,
      onReject: (rateLimiter) =>
        console.log(
          'Rejected by rate limiter',
          rateLimiter.getMsUntilNextWindow(),
        ),
      // optional local storage persister to retain state on page refresh
      initialState: rateLimiterPersister.loadState(),
    },
    // Optional Selector function to pick the state you want to track and use
    (state) => state, // entire state subscription for persister - don't do this unless you need to
  )

  useEffect(() => {
    rateLimiterPersister.saveState(rateLimiter.state)
  }, [rateLimiter.state])

  function increment() {
    // this pattern helps avoid common bugs with stale closures and state
    setInstantCount((c) => {
      const newCount = c + 1 // common new value for both
      rateLimiter.maybeExecute(newCount) // rate-limited state update
      return newCount // instant state update
    })
  }

  return (
    <div>
      <h1>TanStack Pacer useRateLimiter Example 1 (with persister)</h1>
      <div style={{ display: 'grid', gap: '0.5rem', marginBottom: '1rem' }}>
        <label>
          <input
            type="radio"
            name="windowType"
            value="fixed"
            checked={windowType === 'fixed'}
            onChange={() => setWindowType('fixed')}
          />
          Fixed Window
        </label>
        <label>
          <input
            type="radio"
            name="windowType"
            value="sliding"
            checked={windowType === 'sliding'}
            onChange={() => setWindowType('sliding')}
          />
          Sliding Window
        </label>
      </div>
      <table>
        <tbody>
          <tr>
            <td>Execution Count:</td>
            <td>{rateLimiter.state.executionCount}</td>
          </tr>
          <tr>
            <td>Rejection Count:</td>
            <td>{rateLimiter.state.rejectionCount}</td>
          </tr>
          <tr>
            <td>Remaining in Window:</td>
            <td>{rateLimiter.getRemainingInWindow()}</td>
          </tr>
          <tr>
            <td>Ms Until Next Window:</td>
            <td>{rateLimiter.getMsUntilNextWindow()}</td>
          </tr>
          <tr>
            <td colSpan={2}>
              <hr />
            </td>
          </tr>
          <tr>
            <td>Instant Count:</td>
            <td>{instantCount}</td>
          </tr>
          <tr>
            <td>Rate Limited Count:</td>
            <td>{limitedCount}</td>
          </tr>
        </tbody>
      </table>
      <div>
        <button onClick={increment}>Increment</button>
        <button onClick={() => rateLimiter.reset()}>Reset</button>
      </div>
      <pre style={{ marginTop: '20px' }}>
        {JSON.stringify(rateLimiter.store.state, null, 2)}
      </pre>
    </div>
  )
}

function App2() {
  const [instantSearch, setInstantSearch] = useState('')
  const [limitedSearch, setLimitedSearch] = useState('')

  // Using useRateLimiter with a rate limit of 5 executions per 5 seconds
  const rateLimiter = useRateLimiter(
    setLimitedSearch,
    {
      enabled: instantSearch.length > 2, // optional, defaults to true
      limit: 5,
      window: 5000,
      // windowType: 'sliding', // default is 'fixed'
      onReject: (rateLimiter) =>
        console.log(
          'Rejected by rate limiter',
          rateLimiter.getMsUntilNextWindow(),
        ),
    },
    // Optional Selector function to pick the state you want to track and use
    (state) => ({
      executionCount: state.executionCount,
      rejectionCount: state.rejectionCount,
    }),
  )

  function handleSearchChange(e: React.ChangeEvent<HTMLInputElement>) {
    const newValue = e.target.value
    setInstantSearch(newValue)
    rateLimiter.maybeExecute(newValue)
  }

  return (
    <div>
      <h1>TanStack Pacer useRateLimiter Example 2</h1>
      <div>
        <input
          autoFocus
          type="search"
          value={instantSearch}
          onChange={handleSearchChange}
          placeholder="Type to search..."
          style={{ width: '100%' }}
        />
      </div>
      <table>
        <tbody>
          <tr>
            <td>Execution Count:</td>
            <td>{rateLimiter.state.executionCount}</td>
          </tr>
          <tr>
            <td>Rejection Count:</td>
            <td>{rateLimiter.state.rejectionCount}</td>
          </tr>
          <tr>
            <td>Remaining in Window:</td>
            <td>{rateLimiter.getRemainingInWindow()}</td>
          </tr>
          <tr>
            <td>Ms Until Next Window:</td>
            <td>{rateLimiter.getMsUntilNextWindow()}</td>
          </tr>
          <tr>
            <td colSpan={2}>
              <hr />
            </td>
          </tr>
          <tr>
            <td>Instant Search:</td>
          </tr>
          <tr>
            <td>Rate Limited Search:</td>
            <td>{limitedSearch}</td>
          </tr>
        </tbody>
      </table>
      <div>
        <button onClick={() => rateLimiter.reset()}>Reset</button>
      </div>
      <pre style={{ marginTop: '20px' }}>
        {JSON.stringify(rateLimiter.store.state, null, 2)}
      </pre>
    </div>
  )
}

function App3() {
  const [currentValue, setCurrentValue] = useState(50)
  const [limitedValue, setLimitedValue] = useState(50)
  const [instantExecutionCount, setInstantExecutionCount] = useState(0)

  // Using useRateLimiter with a rate limit of 5 executions per 5 seconds
  const rateLimiter = useRateLimiter(
    setLimitedValue,
    {
      limit: 20,
      window: 2000,
      onReject: (rateLimiter) =>
        console.log(
          'Rejected by rate limiter',
          rateLimiter.getMsUntilNextWindow(),
        ),
    },
    // Optional Selector function to pick the state you want to track and use
    (state) => ({
      executionCount: state.executionCount,
      rejectionCount: state.rejectionCount,
    }),
  )

  function handleRangeChange(e: React.ChangeEvent<HTMLInputElement>) {
    const newValue = parseInt(e.target.value, 10)
    setCurrentValue(newValue)
    setInstantExecutionCount((c) => c + 1)
    rateLimiter.maybeExecute(newValue)
  }

  return (
    <div>
      <h1>TanStack Pacer useRateLimiter Example 3</h1>
      <div style={{ marginBottom: '20px' }}>
        <label>
          Current Range:
          <input
            type="range"
            min="0"
            max="100"
            value={currentValue}
            onChange={handleRangeChange}
            style={{ width: '100%' }}
          />
          <span>{currentValue}</span>
        </label>
      </div>
      <div style={{ marginBottom: '20px' }}>
        <label>
          Rate Limited Range (Readonly):
          <input
            type="range"
            min="0"
            max="100"
            value={limitedValue}
            readOnly
            style={{ width: '100%' }}
          />
          <span>{limitedValue}</span>
        </label>
      </div>
      <table>
        <tbody>
          <tr>
            <td>Execution Count:</td>
            <td>{rateLimiter.state.executionCount}</td>
          </tr>
          <tr>
            <td>Rejection Count:</td>
            <td>{rateLimiter.state.rejectionCount}</td>
          </tr>
          <tr>
            <td>Remaining in Window:</td>
            <td>{rateLimiter.getRemainingInWindow()}</td>
          </tr>
          <tr>
            <td>Ms Until Next Window:</td>
            <td>{rateLimiter.getMsUntilNextWindow()}</td>
          </tr>
          <tr>
            <td>Instant Executions:</td>
            <td>{instantExecutionCount}</td>
          </tr>
          <tr>
            <td>Saved Executions:</td>
            <td>{instantExecutionCount - rateLimiter.state.executionCount}</td>
          </tr>
          <tr>
            <td>% Reduction:</td>
            <td>
              {instantExecutionCount === 0
                ? '0'
                : Math.round(
                    ((instantExecutionCount -
                      rateLimiter.state.executionCount) /
                      instantExecutionCount) *
                      100,
                  )}
              %
            </td>
          </tr>
        </tbody>
      </table>
      <div style={{ color: '#666', fontSize: '0.9em' }}>
        <p>Rate limited to 20 updates per 2 seconds</p>
      </div>
      <pre style={{ marginTop: '20px' }}>
        {JSON.stringify(rateLimiter.store.state, null, 2)}
      </pre>
    </div>
  )
}

const root = ReactDOM.createRoot(document.getElementById('root')!)
root.render(
  <div>
    <App1 />
    <hr />
    <App2 />
    <hr />
    <App3 />
  </div>,
)
Our Partners
Unkey
Subscribe to Bytes

Your weekly dose of JavaScript news. Delivered every Monday to over 100,000 devs, for free.

Bytes

No spam. Unsubscribe at any time.

Subscribe to Bytes

Your weekly dose of JavaScript news. Delivered every Monday to over 100,000 devs, for free.

Bytes

No spam. Unsubscribe at any time.