React Example: UseAsyncRateLimiter

Github StackBlitz CodeSandbox

import { useEffect, useState } from 'react'
import ReactDOM from 'react-dom/client'
import { useAsyncRateLimiter } from '@tanstack/react-pacer/async-rate-limiter'

interface SearchResult {
  id: number
  title: string
}

// Simulate API call with fake data
const fakeApi = async (term: string): Promise<Array<SearchResult>> => {
  await new Promise((resolve) => setTimeout(resolve, 300)) // Simulate network delay
  return [
    { id: 1, title: `${term} result ${Math.floor(Math.random() * 100)}` },
    { id: 2, title: `${term} result ${Math.floor(Math.random() * 100)}` },
    { id: 3, title: `${term} result ${Math.floor(Math.random() * 100)}` },
  ]
}

function App() {
  const [windowType, setWindowType] = useState<'fixed' | 'sliding'>('fixed')
  const [searchTerm, setSearchTerm] = useState('')
  const [results, setResults] = useState<Array<SearchResult>>([])
  const [error, setError] = useState<Error | null>(null)

  // The function that will become rate limited
  const handleSearch = async (term: string) => {
    if (!term) {
      setResults([])
      return
    }

    // throw new Error('Test error') // you don't have to catch errors here (though you still can). The onError optional handler will catch it

    const data = await fakeApi(term)
    setResults(data)
    setError(null)

    console.log(setSearchAsyncRateLimiter.state.successCount)
  }

  // hook that gives you an async rate limiter instance
  const setSearchAsyncRateLimiter = useAsyncRateLimiter(
    handleSearch,
    {
      windowType: windowType,
      limit: 3, // Maximum 2 requests
      window: 3000, // per 1 second
      onReject: (rateLimiter) => {
        console.log(
          `Rate limit reached. Try again in ${rateLimiter.getMsUntilNextWindow()}ms`,
        )
      },
      onError: (error) => {
        // optional error handler
        console.error('Search failed:', error)
        setError(error as Error)
        setResults([])
      },
    },
    // Optional Selector function to pick the state you want to track and use
    (state) => ({
      successCount: state.successCount,
      rejectionCount: state.rejectionCount,
      isExecuting: state.isExecuting,
    }),
  )

  // get and name our rate limited function
  const handleSearchRateLimited = setSearchAsyncRateLimiter.maybeExecute

  useEffect(() => {
    console.log('mount')
    return () => {
      console.log('unmount')
      setSearchAsyncRateLimiter.reset() // cancel any pending async calls when the component unmounts
    }
  }, [])

  // instant event handler that calls both the instant local state setter and the rate limited function
  async function onSearchChange(e: React.ChangeEvent<HTMLInputElement>) {
    const newTerm = e.target.value
    setSearchTerm(newTerm)
    await handleSearchRateLimited(newTerm) // optionally await if you need to
  }

  return (
    <div>
      <h1>TanStack Pacer useAsyncRateLimiter Example</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>
      <div>
        <input
          autoFocus
          type="search"
          value={searchTerm}
          onChange={onSearchChange}
          placeholder="Type to search..."
          style={{ width: '100%' }}
          autoComplete="new-password"
        />
      </div>
      {error && <div>Error: {error.message}</div>}
      <div>
        <table>
          <tbody>
            <tr>
              <td>API calls made:</td>
              <td>{setSearchAsyncRateLimiter.state.successCount}</td>
            </tr>
            <tr>
              <td>Rejected calls:</td>
              <td>{setSearchAsyncRateLimiter.state.rejectionCount}</td>
            </tr>
            <tr>
              <td>Is executing:</td>
              <td>
                {setSearchAsyncRateLimiter.state.isExecuting ? 'Yes' : 'No'}
              </td>
            </tr>
            <tr>
              <td>Results:</td>
              <td>
                {results.length > 0 ? (
                  <ul>
                    {results.map((item) => (
                      <li key={item.id}>{item.title}</li>
                    ))}
                  </ul>
                ) : (
                  'No results'
                )}
              </td>
            </tr>
          </tbody>
        </table>
      </div>
      <pre style={{ marginTop: '20px' }}>
        {JSON.stringify(setSearchAsyncRateLimiter.store.state, null, 2)}
      </pre>
    </div>
  )
}

const root = ReactDOM.createRoot(document.getElementById('root')!)

let mounted = true
root.render(<App />)

// demo unmounting and cancellation
document.addEventListener('keydown', (e) => {
  if (e.key === 'Enter') {
    mounted = !mounted
    root.render(mounted ? <App /> : null)
  }
})

import { useEffect, useState } from 'react'
import ReactDOM from 'react-dom/client'
import { useAsyncRateLimiter } from '@tanstack/react-pacer/async-rate-limiter'

interface SearchResult {
  id: number
  title: string
}

// Simulate API call with fake data
const fakeApi = async (term: string): Promise<Array<SearchResult>> => {
  await new Promise((resolve) => setTimeout(resolve, 300)) // Simulate network delay
  return [
    { id: 1, title: `${term} result ${Math.floor(Math.random() * 100)}` },
    { id: 2, title: `${term} result ${Math.floor(Math.random() * 100)}` },
    { id: 3, title: `${term} result ${Math.floor(Math.random() * 100)}` },
  ]
}

function App() {
  const [windowType, setWindowType] = useState<'fixed' | 'sliding'>('fixed')
  const [searchTerm, setSearchTerm] = useState('')
  const [results, setResults] = useState<Array<SearchResult>>([])
  const [error, setError] = useState<Error | null>(null)

  // The function that will become rate limited
  const handleSearch = async (term: string) => {
    if (!term) {
      setResults([])
      return
    }

    // throw new Error('Test error') // you don't have to catch errors here (though you still can). The onError optional handler will catch it

    const data = await fakeApi(term)
    setResults(data)
    setError(null)

    console.log(setSearchAsyncRateLimiter.state.successCount)
  }

  // hook that gives you an async rate limiter instance
  const setSearchAsyncRateLimiter = useAsyncRateLimiter(
    handleSearch,
    {
      windowType: windowType,
      limit: 3, // Maximum 2 requests
      window: 3000, // per 1 second
      onReject: (rateLimiter) => {
        console.log(
          `Rate limit reached. Try again in ${rateLimiter.getMsUntilNextWindow()}ms`,
        )
      },
      onError: (error) => {
        // optional error handler
        console.error('Search failed:', error)
        setError(error as Error)
        setResults([])
      },
    },
    // Optional Selector function to pick the state you want to track and use
    (state) => ({
      successCount: state.successCount,
      rejectionCount: state.rejectionCount,
      isExecuting: state.isExecuting,
    }),
  )

  // get and name our rate limited function
  const handleSearchRateLimited = setSearchAsyncRateLimiter.maybeExecute

  useEffect(() => {
    console.log('mount')
    return () => {
      console.log('unmount')
      setSearchAsyncRateLimiter.reset() // cancel any pending async calls when the component unmounts
    }
  }, [])

  // instant event handler that calls both the instant local state setter and the rate limited function
  async function onSearchChange(e: React.ChangeEvent<HTMLInputElement>) {
    const newTerm = e.target.value
    setSearchTerm(newTerm)
    await handleSearchRateLimited(newTerm) // optionally await if you need to
  }

  return (
    <div>
      <h1>TanStack Pacer useAsyncRateLimiter Example</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>
      <div>
        <input
          autoFocus
          type="search"
          value={searchTerm}
          onChange={onSearchChange}
          placeholder="Type to search..."
          style={{ width: '100%' }}
          autoComplete="new-password"
        />
      </div>
      {error && <div>Error: {error.message}</div>}
      <div>
        <table>
          <tbody>
            <tr>
              <td>API calls made:</td>
              <td>{setSearchAsyncRateLimiter.state.successCount}</td>
            </tr>
            <tr>
              <td>Rejected calls:</td>
              <td>{setSearchAsyncRateLimiter.state.rejectionCount}</td>
            </tr>
            <tr>
              <td>Is executing:</td>
              <td>
                {setSearchAsyncRateLimiter.state.isExecuting ? 'Yes' : 'No'}
              </td>
            </tr>
            <tr>
              <td>Results:</td>
              <td>
                {results.length > 0 ? (
                  <ul>
                    {results.map((item) => (
                      <li key={item.id}>{item.title}</li>
                    ))}
                  </ul>
                ) : (
                  'No results'
                )}
              </td>
            </tr>
          </tbody>
        </table>
      </div>
      <pre style={{ marginTop: '20px' }}>
        {JSON.stringify(setSearchAsyncRateLimiter.store.state, null, 2)}
      </pre>
    </div>
  )
}

const root = ReactDOM.createRoot(document.getElementById('root')!)

let mounted = true
root.render(<App />)

// demo unmounting and cancellation
document.addEventListener('keydown', (e) => {
  if (e.key === 'Enter') {
    mounted = !mounted
    root.render(mounted ? <App /> : null)
  }
})