import { useState } from 'react'
import ReactDOM from 'react-dom/client'
import { useDebouncedValue } from '@tanstack/react-pacer/debouncer'
function App1() {
const [instantCount, setInstantCount] = useState(0)
function increment() {
setInstantCount((c) => c + 1)
}
// highest-level hook that watches an instant local state value and returns a debounced value
const [debouncedCount] = useDebouncedValue(instantCount, {
wait: 500,
// enabled: () => instantCount > 2, // optional, defaults to true
// leading: true, // optional, defaults to false
})
return (
<div>
<h1>TanStack Pacer useDebouncedValue Example 1</h1>
<table>
<tbody>
<tr>
<td>Instant Count:</td>
<td>{instantCount}</td>
</tr>
<tr>
<td>Debounced Count:</td>
<td>{debouncedCount}</td>
</tr>
</tbody>
</table>
<div>
<button onClick={increment}>Increment</button>
</div>
</div>
)
}
function App2() {
const [instantSearch, setInstantSearch] = useState('')
// highest-level hook that watches an instant local state value and returns a debounced value
// optionally, grab the debouncer from the last index of the returned array
const [debouncedSearch] = useDebouncedValue(instantSearch, {
wait: 500,
enabled: instantSearch.length > 2, // optional, defaults to true
})
function handleSearchChange(e: React.ChangeEvent<HTMLInputElement>) {
setInstantSearch(e.target.value)
}
return (
<div>
<h1>TanStack Pacer useDebouncedValue Example 2</h1>
<div>
<input
autoFocus
type="search"
value={instantSearch}
onChange={handleSearchChange}
placeholder="Type to search..."
style={{ width: '100%' }}
/>
</div>
<table>
<tbody>
<tr>
<td>Instant Search:</td>
<td>{instantSearch}</td>
</tr>
<tr>
<td>Debounced Search:</td>
<td>{debouncedSearch}</td>
</tr>
</tbody>
</table>
</div>
)
}
function App3() {
const [currentValue, setCurrentValue] = useState(50)
const [instantExecutionCount, setInstantExecutionCount] = useState(0)
// highest-level hook that watches an instant local state value and returns a debounced value
const [debouncedValue, debouncer] = useDebouncedValue(currentValue, {
wait: 250,
})
function handleRangeChange(e: React.ChangeEvent<HTMLInputElement>) {
const newValue = parseInt(e.target.value, 10)
setCurrentValue(newValue)
setInstantExecutionCount((c) => c + 1)
}
return (
<div>
<h1>TanStack Pacer useDebouncedValue 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>
Debounced Range (Readonly):
<input
type="range"
min="0"
max="100"
value={debouncedValue}
readOnly
style={{ width: '100%' }}
/>
<span>{debouncedValue}</span>
</label>
</div>
<table>
<tbody>
<tr>
<td>Enabled:</td>
<td>{debouncer.getOptions().enabled.toString()}</td>
</tr>
<tr>
<td>Is Pending:</td>
<td>{debouncer.getIsPending().toString()}</td>
</tr>
<tr>
<td>Instant Executions:</td>
<td>{instantExecutionCount}</td>
</tr>
<tr>
<td>Debounced Executions:</td>
<td>{debouncer.getExecutionCount()}</td>
</tr>
<tr>
<td>Saved Executions:</td>
<td>{instantExecutionCount - debouncer.getExecutionCount()}</td>
</tr>
<tr>
<td>% Reduction:</td>
<td>
{instantExecutionCount === 0
? '0'
: Math.round(
((instantExecutionCount - debouncer.getExecutionCount()) /
instantExecutionCount) *
100,
)}
%
</td>
</tr>
</tbody>
</table>
<div style={{ color: '#666', fontSize: '0.9em' }}>
<p>Debounced to 250ms wait time</p>
</div>
</div>
)
}
const root = ReactDOM.createRoot(document.getElementById('root')!)
root.render(
<div>
<App1 />
<hr />
<App2 />
<hr />
<App3 />
</div>,
)
import { useState } from 'react'
import ReactDOM from 'react-dom/client'
import { useDebouncedValue } from '@tanstack/react-pacer/debouncer'
function App1() {
const [instantCount, setInstantCount] = useState(0)
function increment() {
setInstantCount((c) => c + 1)
}
// highest-level hook that watches an instant local state value and returns a debounced value
const [debouncedCount] = useDebouncedValue(instantCount, {
wait: 500,
// enabled: () => instantCount > 2, // optional, defaults to true
// leading: true, // optional, defaults to false
})
return (
<div>
<h1>TanStack Pacer useDebouncedValue Example 1</h1>
<table>
<tbody>
<tr>
<td>Instant Count:</td>
<td>{instantCount}</td>
</tr>
<tr>
<td>Debounced Count:</td>
<td>{debouncedCount}</td>
</tr>
</tbody>
</table>
<div>
<button onClick={increment}>Increment</button>
</div>
</div>
)
}
function App2() {
const [instantSearch, setInstantSearch] = useState('')
// highest-level hook that watches an instant local state value and returns a debounced value
// optionally, grab the debouncer from the last index of the returned array
const [debouncedSearch] = useDebouncedValue(instantSearch, {
wait: 500,
enabled: instantSearch.length > 2, // optional, defaults to true
})
function handleSearchChange(e: React.ChangeEvent<HTMLInputElement>) {
setInstantSearch(e.target.value)
}
return (
<div>
<h1>TanStack Pacer useDebouncedValue Example 2</h1>
<div>
<input
autoFocus
type="search"
value={instantSearch}
onChange={handleSearchChange}
placeholder="Type to search..."
style={{ width: '100%' }}
/>
</div>
<table>
<tbody>
<tr>
<td>Instant Search:</td>
<td>{instantSearch}</td>
</tr>
<tr>
<td>Debounced Search:</td>
<td>{debouncedSearch}</td>
</tr>
</tbody>
</table>
</div>
)
}
function App3() {
const [currentValue, setCurrentValue] = useState(50)
const [instantExecutionCount, setInstantExecutionCount] = useState(0)
// highest-level hook that watches an instant local state value and returns a debounced value
const [debouncedValue, debouncer] = useDebouncedValue(currentValue, {
wait: 250,
})
function handleRangeChange(e: React.ChangeEvent<HTMLInputElement>) {
const newValue = parseInt(e.target.value, 10)
setCurrentValue(newValue)
setInstantExecutionCount((c) => c + 1)
}
return (
<div>
<h1>TanStack Pacer useDebouncedValue 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>
Debounced Range (Readonly):
<input
type="range"
min="0"
max="100"
value={debouncedValue}
readOnly
style={{ width: '100%' }}
/>
<span>{debouncedValue}</span>
</label>
</div>
<table>
<tbody>
<tr>
<td>Enabled:</td>
<td>{debouncer.getOptions().enabled.toString()}</td>
</tr>
<tr>
<td>Is Pending:</td>
<td>{debouncer.getIsPending().toString()}</td>
</tr>
<tr>
<td>Instant Executions:</td>
<td>{instantExecutionCount}</td>
</tr>
<tr>
<td>Debounced Executions:</td>
<td>{debouncer.getExecutionCount()}</td>
</tr>
<tr>
<td>Saved Executions:</td>
<td>{instantExecutionCount - debouncer.getExecutionCount()}</td>
</tr>
<tr>
<td>% Reduction:</td>
<td>
{instantExecutionCount === 0
? '0'
: Math.round(
((instantExecutionCount - debouncer.getExecutionCount()) /
instantExecutionCount) *
100,
)}
%
</td>
</tr>
</tbody>
</table>
<div style={{ color: '#666', fontSize: '0.9em' }}>
<p>Debounced to 250ms wait time</p>
</div>
</div>
)
}
const root = ReactDOM.createRoot(document.getElementById('root')!)
root.render(
<div>
<App1 />
<hr />
<App2 />
<hr />
<App3 />
</div>,
)
Your weekly dose of JavaScript news. Delivered every Monday to over 100,000 devs, for free.