Octane Example: UseDebouncedState

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import { useRef, useState } from 'octane'
import { createRoot } from 'octane'
import { useDebouncedState } from '@tanstack/octane-pacer/debouncer'

function App1() {
  const [instantCount, setInstantCount] = useState(0)
  const instantCountRef = useRef(0)

  // higher-level hook that uses Octane.useState with the state setter automatically debounced
  // optionally, grab the debouncer from the last index of the returned array
  const [debouncedCount, setDebouncedCount, debouncer] = useDebouncedState(
    instantCount,
    {
      wait: 500,
      // enabled: () => instantCountRef.current > 2, // optional, defaults to true
      // leading: true, // optional, defaults to false
    },
    // Alternative to debouncer.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)
    setDebouncedCount(nextCount)
  }

  return (
    <div>
      <h1>{'TanStack Pacer useDebouncedState Example 1'}</h1>
      <table>
        <tbody>
          <debouncer.Subscribe
            selector={(state) => ({
              isPending: state.isPending,
              executionCount: state.executionCount,
            })}
          >
            {({ isPending, executionCount }) => (
              <>
                <tr>
                  <td>{'Is Pending:'}</td>
                  <td>{isPending.toString()}</td>
                </tr>
                <tr>
                  <td>{'Execution Count:'}</td>
                  <td>{executionCount}</td>
                </tr>
                <tr>
                  <td colSpan={2}>
                    <hr />
                  </td>
                </tr>
                <tr>
                  <td>{'Instant Count:'}</td>
                  <td>{instantCount}</td>
                </tr>
                <tr>
                  <td>{'Debounced Count:'}</td>
                  <td>{debouncedCount}</td>
                </tr>
              </>
            )}
          </debouncer.Subscribe>
        </tbody>
      </table>
      <div>
        <button onClick={increment}>{'Increment'}</button>
      </div>
      <debouncer.Subscribe selector={(state) => state}>
        {(state) => (
          <pre style={{ marginTop: '20px' }}>
            {JSON.stringify(state, null, 2)}
          </pre>
        )}
      </debouncer.Subscribe>
    </div>
  )
}

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

  // higher-level hook that uses Octane.useState with the state setter automatically debounced
  const [debouncedSearch, setDebouncedSearch, debouncer] = useDebouncedState(
    instantSearch,
    {
      wait: 500,
      enabled: () => instantSearchRef.current.length > 2, // optional, defaults to true
    },
    // Alternative to debouncer.Subscribe: pass a selector as 3rd arg to cause re-renders and subscribe to state
    // (state) => state,
  )

  function handleSearchChange(e: Event & { currentTarget: HTMLInputElement }) {
    const newValue = e.currentTarget.value
    instantSearchRef.current = newValue
    setInstantSearch(newValue)
    setDebouncedSearch(newValue)
  }

  return (
    <div>
      <h1>{'TanStack Pacer useDebouncedState Example 2'}</h1>
      <div>
        <input
          autoFocus
          type="search"
          value={instantSearch}
          onInput={handleSearchChange}
          placeholder="Type to search..."
          style={{ width: '100%' }}
        />
      </div>
      <table>
        <tbody>
          <debouncer.Subscribe
            selector={(state) => ({
              isPending: state.isPending,
              executionCount: state.executionCount,
            })}
          >
            {({ isPending, executionCount }) => (
              <>
                <tr>
                  <td>{'Is Pending:'}</td>
                  <td>{isPending.toString()}</td>
                </tr>
                <tr>
                  <td>{'Execution Count:'}</td>
                  <td>{executionCount}</td>
                </tr>
                <tr>
                  <td colSpan={2}>
                    <hr />
                  </td>
                </tr>
                <tr>
                  <td>{'Instant Search:'}</td>
                  <td>{instantSearch}</td>
                </tr>
                <tr>
                  <td>{'Debounced Search:'}</td>
                  <td>{debouncedSearch}</td>
                </tr>
              </>
            )}
          </debouncer.Subscribe>
        </tbody>
      </table>
      <debouncer.Subscribe selector={(state) => state}>
        {(state) => (
          <pre style={{ marginTop: '20px' }}>
            {JSON.stringify(state, null, 2)}
          </pre>
        )}
      </debouncer.Subscribe>
    </div>
  )
}

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

  // higher-level hook that uses Octane.useState with the state setter automatically debounced
  const [debouncedValue, setDebouncedValue, debouncer] = useDebouncedState(
    currentValue,
    {
      wait: 250,
    },
    // Alternative to debouncer.Subscribe: pass a selector as 3rd arg to cause re-renders and subscribe to state
    // (state) => state,
  )

  function handleRangeChange(e: Event & { currentTarget: HTMLInputElement }) {
    const newValue = parseInt(e.currentTarget.value, 10)
    setCurrentValue(newValue)
    setInstantExecutionCount((c) => c + 1)
    setDebouncedValue(newValue)
  }

  return (
    <div>
      <h1>{'TanStack Pacer useDebouncedState 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>
          {'Debounced Range (Readonly):'}
          <input
            type="range"
            min="0"
            max="100"
            value={debouncedValue}
            disabled
            style={{ width: '100%' }}
          />
          <span>{debouncedValue}</span>
        </label>
      </div>
      <table>
        <tbody>
          <debouncer.Subscribe
            selector={(state) => ({
              isPending: state.isPending,
              executionCount: state.executionCount,
            })}
          >
            {({ isPending, executionCount }) => (
              <>
                <tr>
                  <td>{'Is Pending:'}</td>
                  <td>{isPending.toString()}</td>
                </tr>
                <tr>
                  <td>{'Instant Executions:'}</td>
                  <td>{instantExecutionCount}</td>
                </tr>
                <tr>
                  <td>{'Debounced Executions:'}</td>
                  <td>{executionCount}</td>
                </tr>
                <tr>
                  <td>{'Saved Executions:'}</td>
                  <td>{instantExecutionCount - executionCount}</td>
                </tr>
                <tr>
                  <td>{'% Reduction:'}</td>
                  <td>
                    {instantExecutionCount === 0
                      ? '0'
                      : Math.round(
                          ((instantExecutionCount - executionCount) /
                            instantExecutionCount) *
                            100,
                        )}
                    {'%'}
                  </td>
                </tr>
              </>
            )}
          </debouncer.Subscribe>
        </tbody>
      </table>
      <div style={{ color: '#666', fontSize: '0.9em' }}>
        <p>{'Debounced to 250ms wait time'}</p>
      </div>
      <debouncer.Subscribe selector={(state) => state}>
        {(state) => (
          <pre style={{ marginTop: '20px' }}>
            {JSON.stringify(state, null, 2)}
          </pre>
        )}
      </debouncer.Subscribe>
    </div>
  )
}

function PacerExample() {
  return (
    <div>
      <App1 />
      <hr />
      <App2 />
      <hr />
      <App3 />
    </div>
  )
}
createRoot(document.getElementById('app')!).render(PacerExample)