Preact Example: UseThrottler

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import { useRef, useState } from 'preact/hooks'
import { render } from 'preact'
import type { TargetedEvent } from 'preact'
import { useThrottler } from '@tanstack/preact-pacer/throttler'
import { PacerProvider } from '@tanstack/preact-pacer/provider'

function App1() {
  // Use your state management library of choice
  const [instantCount, setInstantCount] = useState(0)
  const instantCountRef = useRef(0)
  const [throttledCount, setThrottledCount] = useState(0)

  // Lower-level useThrottler hook - requires you to manage your own state
  // No selector needed - we'll use Subscribe HOC to subscribe to state in the component tree
  const setCountThrottler = useThrottler(
    setThrottledCount,
    {
      wait: 1000,
      // leading: true, // default
      // trailing: true, // default
      // enabled: () => instantCountRef.current > 2,
    },
    // Alternative to setCountThrottler.Subscribe: pass a selector as 3rd arg to cause re-renders and subscribe to state
    // (state) => state,
  )

  function increment() {
    const nextCount = ++instantCountRef.current
    setInstantCount(nextCount)
    setCountThrottler.maybeExecute(nextCount)
  }

  return (
    <div>
      <h1>TanStack Pacer useThrottler Example 1</h1>
      <table>
        <tbody>
          <setCountThrottler.Subscribe
            selector={(state) => ({ executionCount: state.executionCount })}
          >
            {({ executionCount }) => (
              <>
                <tr>
                  <td>Execution Count:</td>
                  <td>{executionCount}</td>
                </tr>
                <tr>
                  <td>Instant Count:</td>
                  <td>{instantCount}</td>
                </tr>
                <tr>
                  <td>Throttled Count:</td>
                  <td>{throttledCount}</td>
                </tr>
              </>
            )}
          </setCountThrottler.Subscribe>
        </tbody>
      </table>
      <div>
        <button onClick={increment}>Increment</button>
        <button
          onClick={() => setCountThrottler.flush()}
          style={{ marginLeft: '10px' }}
        >
          Flush
        </button>
      </div>
      <setCountThrottler.Subscribe selector={(state) => state}>
        {(state) => (
          <pre style={{ marginTop: '20px' }}>
            {JSON.stringify(state, null, 2)}
          </pre>
        )}
      </setCountThrottler.Subscribe>
    </div>
  )
}

function App2() {
  const [instantSearch, setInstantSearch] = useState('')
  const instantSearchRef = useRef('')
  const [throttledSearch, setThrottledSearch] = useState('')

  // Lower-level useThrottler hook - requires you to manage your own state
  // No selector needed - we'll use Subscribe HOC to subscribe to state in the component tree
  const setSearchThrottler = useThrottler(
    setThrottledSearch,
    {
      wait: 1000,
      enabled: () => instantSearchRef.current.length > 2,
    },
    // Alternative to setSearchThrottler.Subscribe: pass a selector as 3rd arg to cause re-renders and subscribe to state
    // (state) => state,
  )

  function handleSearchChange(e: TargetedEvent<HTMLInputElement>) {
    const newValue = e.currentTarget.value
    instantSearchRef.current = newValue
    setInstantSearch(newValue)
    setSearchThrottler.maybeExecute(newValue)
  }

  return (
    <div>
      <h1>TanStack Pacer useThrottler Example 2</h1>
      <div>
        <input
          autoFocus
          type="search"
          value={instantSearch}
          onInput={handleSearchChange}
          placeholder="Type to search..."
          style={{ width: '100%' }}
        />
      </div>
      <table>
        <tbody>
          <setSearchThrottler.Subscribe
            selector={(state) => ({ executionCount: state.executionCount })}
          >
            {({ executionCount }) => (
              <>
                <tr>
                  <td>Execution Count:</td>
                  <td>{executionCount}</td>
                </tr>
                <tr>
                  <td>Instant Search:</td>
                  <td>{instantSearch}</td>
                </tr>
                <tr>
                  <td>Throttled Search:</td>
                  <td>{throttledSearch}</td>
                </tr>
              </>
            )}
          </setSearchThrottler.Subscribe>
        </tbody>
      </table>
      <div>
        <button onClick={() => setSearchThrottler.flush()}>Flush</button>
      </div>
      <setSearchThrottler.Subscribe selector={(state) => state}>
        {(state) => (
          <pre style={{ marginTop: '20px' }}>
            {JSON.stringify(state, null, 2)}
          </pre>
        )}
      </setSearchThrottler.Subscribe>
    </div>
  )
}

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

  // Lower-level useThrottler hook - requires you to manage your own state
  // No selector needed - we'll use Subscribe HOC to subscribe to state in the component tree
  const setValueThrottler = useThrottler(
    setThrottledValue,
    {
      wait: 250,
      // leading: true, // default
      // trailing: true, // default
    },
    // Alternative to setValueThrottler.Subscribe: pass a selector as 3rd arg to cause re-renders and subscribe to state
    // (state) => state,
  )

  function handleRangeChange(e: TargetedEvent<HTMLInputElement>) {
    const newValue = parseInt(e.currentTarget.value, 10)

    // instant state update
    setCurrentValue(newValue)
    setInstantExecutionCount((c) => c + 1)

    // throttled state update
    setValueThrottler.maybeExecute(newValue)
  }

  return (
    <div>
      <h1>TanStack Pacer useThrottler Example 3</h1>
      <div style={{ marginBottom: '20px' }}>
        <label>
          Current Range:
          <input
            type="range"
            min="0"
            max="100"
            value={currentValue}
            onInput={handleRangeChange}
            style={{ width: '100%' }}
          />
          <span>{currentValue}</span>
        </label>
      </div>
      <div style={{ marginBottom: '20px' }}>
        <label>
          Throttled Range (Readonly):
          <input
            type="range"
            min="0"
            max="100"
            value={throttledValue}
            disabled
            style={{ width: '100%' }}
          />
          <span>{throttledValue}</span>
        </label>
      </div>
      <table>
        <tbody>
          <setValueThrottler.Subscribe
            selector={(state) => ({ executionCount: state.executionCount })}
          >
            {({ executionCount }) => (
              <>
                <tr>
                  <td>Instant Execution Count:</td>
                  <td>{instantExecutionCount}</td>
                </tr>
                <tr>
                  <td>Throttled Execution Count:</td>
                  <td>{executionCount}</td>
                </tr>
                <tr>
                  <td>Saved Executions:</td>
                  <td>
                    {instantExecutionCount - executionCount} (
                    {instantExecutionCount > 0
                      ? (
                          ((instantExecutionCount - executionCount) /
                            instantExecutionCount) *
                          100
                        ).toFixed(2)
                      : 0}
                    % Reduction in execution calls)
                  </td>
                </tr>
              </>
            )}
          </setValueThrottler.Subscribe>
        </tbody>
      </table>
      <div style={{ color: '#666', fontSize: '0.9em' }}>
        <p>Throttled to 1 update per 250ms (trailing edge)</p>
      </div>
      <div>
        <button onClick={() => setValueThrottler.flush()}>Flush</button>
      </div>
      <setValueThrottler.Subscribe selector={(state) => state}>
        {(state) => (
          <pre style={{ marginTop: '20px' }}>
            {JSON.stringify(state, null, 2)}
          </pre>
        )}
      </setValueThrottler.Subscribe>
    </div>
  )
}

const root = document.getElementById('root')!
render(
  // optionally, provide default options to an optional PacerProvider
  <PacerProvider
  // defaultOptions={{
  //   throttler: {
  //     leading: true,
  //   },
  // }}
  >
    <div>
      <App1 />
      <hr />
      <App2 />
      <hr />
      <App3 />
    </div>
  </PacerProvider>,
  root,
)

import { useRef, useState } from 'preact/hooks'
import { render } from 'preact'
import type { TargetedEvent } from 'preact'
import { useThrottler } from '@tanstack/preact-pacer/throttler'
import { PacerProvider } from '@tanstack/preact-pacer/provider'

function App1() {
  // Use your state management library of choice
  const [instantCount, setInstantCount] = useState(0)
  const instantCountRef = useRef(0)
  const [throttledCount, setThrottledCount] = useState(0)

  // Lower-level useThrottler hook - requires you to manage your own state
  // No selector needed - we'll use Subscribe HOC to subscribe to state in the component tree
  const setCountThrottler = useThrottler(
    setThrottledCount,
    {
      wait: 1000,
      // leading: true, // default
      // trailing: true, // default
      // enabled: () => instantCountRef.current > 2,
    },
    // Alternative to setCountThrottler.Subscribe: pass a selector as 3rd arg to cause re-renders and subscribe to state
    // (state) => state,
  )

  function increment() {
    const nextCount = ++instantCountRef.current
    setInstantCount(nextCount)
    setCountThrottler.maybeExecute(nextCount)
  }

  return (
    <div>
      <h1>TanStack Pacer useThrottler Example 1</h1>
      <table>
        <tbody>
          <setCountThrottler.Subscribe
            selector={(state) => ({ executionCount: state.executionCount })}
          >
            {({ executionCount }) => (
              <>
                <tr>
                  <td>Execution Count:</td>
                  <td>{executionCount}</td>
                </tr>
                <tr>
                  <td>Instant Count:</td>
                  <td>{instantCount}</td>
                </tr>
                <tr>
                  <td>Throttled Count:</td>
                  <td>{throttledCount}</td>
                </tr>
              </>
            )}
          </setCountThrottler.Subscribe>
        </tbody>
      </table>
      <div>
        <button onClick={increment}>Increment</button>
        <button
          onClick={() => setCountThrottler.flush()}
          style={{ marginLeft: '10px' }}
        >
          Flush
        </button>
      </div>
      <setCountThrottler.Subscribe selector={(state) => state}>
        {(state) => (
          <pre style={{ marginTop: '20px' }}>
            {JSON.stringify(state, null, 2)}
          </pre>
        )}
      </setCountThrottler.Subscribe>
    </div>
  )
}

function App2() {
  const [instantSearch, setInstantSearch] = useState('')
  const instantSearchRef = useRef('')
  const [throttledSearch, setThrottledSearch] = useState('')

  // Lower-level useThrottler hook - requires you to manage your own state
  // No selector needed - we'll use Subscribe HOC to subscribe to state in the component tree
  const setSearchThrottler = useThrottler(
    setThrottledSearch,
    {
      wait: 1000,
      enabled: () => instantSearchRef.current.length > 2,
    },
    // Alternative to setSearchThrottler.Subscribe: pass a selector as 3rd arg to cause re-renders and subscribe to state
    // (state) => state,
  )

  function handleSearchChange(e: TargetedEvent<HTMLInputElement>) {
    const newValue = e.currentTarget.value
    instantSearchRef.current = newValue
    setInstantSearch(newValue)
    setSearchThrottler.maybeExecute(newValue)
  }

  return (
    <div>
      <h1>TanStack Pacer useThrottler Example 2</h1>
      <div>
        <input
          autoFocus
          type="search"
          value={instantSearch}
          onInput={handleSearchChange}
          placeholder="Type to search..."
          style={{ width: '100%' }}
        />
      </div>
      <table>
        <tbody>
          <setSearchThrottler.Subscribe
            selector={(state) => ({ executionCount: state.executionCount })}
          >
            {({ executionCount }) => (
              <>
                <tr>
                  <td>Execution Count:</td>
                  <td>{executionCount}</td>
                </tr>
                <tr>
                  <td>Instant Search:</td>
                  <td>{instantSearch}</td>
                </tr>
                <tr>
                  <td>Throttled Search:</td>
                  <td>{throttledSearch}</td>
                </tr>
              </>
            )}
          </setSearchThrottler.Subscribe>
        </tbody>
      </table>
      <div>
        <button onClick={() => setSearchThrottler.flush()}>Flush</button>
      </div>
      <setSearchThrottler.Subscribe selector={(state) => state}>
        {(state) => (
          <pre style={{ marginTop: '20px' }}>
            {JSON.stringify(state, null, 2)}
          </pre>
        )}
      </setSearchThrottler.Subscribe>
    </div>
  )
}

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

  // Lower-level useThrottler hook - requires you to manage your own state
  // No selector needed - we'll use Subscribe HOC to subscribe to state in the component tree
  const setValueThrottler = useThrottler(
    setThrottledValue,
    {
      wait: 250,
      // leading: true, // default
      // trailing: true, // default
    },
    // Alternative to setValueThrottler.Subscribe: pass a selector as 3rd arg to cause re-renders and subscribe to state
    // (state) => state,
  )

  function handleRangeChange(e: TargetedEvent<HTMLInputElement>) {
    const newValue = parseInt(e.currentTarget.value, 10)

    // instant state update
    setCurrentValue(newValue)
    setInstantExecutionCount((c) => c + 1)

    // throttled state update
    setValueThrottler.maybeExecute(newValue)
  }

  return (
    <div>
      <h1>TanStack Pacer useThrottler Example 3</h1>
      <div style={{ marginBottom: '20px' }}>
        <label>
          Current Range:
          <input
            type="range"
            min="0"
            max="100"
            value={currentValue}
            onInput={handleRangeChange}
            style={{ width: '100%' }}
          />
          <span>{currentValue}</span>
        </label>
      </div>
      <div style={{ marginBottom: '20px' }}>
        <label>
          Throttled Range (Readonly):
          <input
            type="range"
            min="0"
            max="100"
            value={throttledValue}
            disabled
            style={{ width: '100%' }}
          />
          <span>{throttledValue}</span>
        </label>
      </div>
      <table>
        <tbody>
          <setValueThrottler.Subscribe
            selector={(state) => ({ executionCount: state.executionCount })}
          >
            {({ executionCount }) => (
              <>
                <tr>
                  <td>Instant Execution Count:</td>
                  <td>{instantExecutionCount}</td>
                </tr>
                <tr>
                  <td>Throttled Execution Count:</td>
                  <td>{executionCount}</td>
                </tr>
                <tr>
                  <td>Saved Executions:</td>
                  <td>
                    {instantExecutionCount - executionCount} (
                    {instantExecutionCount > 0
                      ? (
                          ((instantExecutionCount - executionCount) /
                            instantExecutionCount) *
                          100
                        ).toFixed(2)
                      : 0}
                    % Reduction in execution calls)
                  </td>
                </tr>
              </>
            )}
          </setValueThrottler.Subscribe>
        </tbody>
      </table>
      <div style={{ color: '#666', fontSize: '0.9em' }}>
        <p>Throttled to 1 update per 250ms (trailing edge)</p>
      </div>
      <div>
        <button onClick={() => setValueThrottler.flush()}>Flush</button>
      </div>
      <setValueThrottler.Subscribe selector={(state) => state}>
        {(state) => (
          <pre style={{ marginTop: '20px' }}>
            {JSON.stringify(state, null, 2)}
          </pre>
        )}
      </setValueThrottler.Subscribe>
    </div>
  )
}

const root = document.getElementById('root')!
render(
  // optionally, provide default options to an optional PacerProvider
  <PacerProvider
  // defaultOptions={{
  //   throttler: {
  //     leading: true,
  //   },
  // }}
  >
    <div>
      <App1 />
      <hr />
      <App2 />
      <hr />
      <App3 />
    </div>
  </PacerProvider>,
  root,
)