React Example: UseQueuedState
tsx
import ReactDOM from 'react-dom/client'
import { useQueuedState } from '@tanstack/react-pacer/queuer'
import { useState } from 'react'
function App1() {
// Queuer that uses React.useState under the hood
const [queueItems, addItem, queuer] = useQueuedState({
maxSize: 25,
initialItems: [1, 2, 3, 4, 5, 6, 7, 8, 9, 10],
started: false,
wait: 1000, // wait 1 second between processing items - wait is optional!
})
return (
<div>
<h1>TanStack Pacer useQueuedState Example 1</h1>
<div>Queue Size: {queuer.getSize()}</div>
<div>Queue Max Size: {25}</div>
<div>Queue Full: {queuer.getIsFull() ? 'Yes' : 'No'}</div>
<div>Queue Peek: {queuer.getPeek()}</div>
<div>Queue Empty: {queuer.getIsEmpty() ? 'Yes' : 'No'}</div>
<div>Queue Idle: {queuer.getIsIdle() ? 'Yes' : 'No'}</div>
<div>Queuer Status: {queuer.getIsRunning() ? 'Running' : 'Stopped'}</div>
<div>Items Processed: {queuer.getExecutionCount()}</div>
<div>Queue Items: {queueItems.join(', ')}</div>
<div
style={{
display: 'grid',
gridTemplateColumns: 'repeat(2, 1fr)',
gap: '8px',
maxWidth: '600px',
margin: '16px 0',
}}
>
<button
onClick={() => {
const nextNumber = queueItems.length
? queueItems[queueItems.length - 1] + 1
: 1
addItem(nextNumber)
}}
disabled={queuer.getIsFull()}
>
Add Number
</button>
<button
disabled={queuer.getIsEmpty()}
onClick={() => {
const item = queuer.getNextItem()
console.log('getNextItem item', item)
}}
>
Process Next
</button>
<button onClick={() => queuer.clear()} disabled={queuer.getIsEmpty()}>
Clear Queue
</button>
<button onClick={() => queuer.reset()} disabled={queuer.getIsEmpty()}>
Reset Queue
</button>
<button onClick={() => queuer.start()} disabled={queuer.getIsRunning()}>
Start Processing
</button>
<button onClick={() => queuer.stop()} disabled={!queuer.getIsRunning()}>
Stop Processing
</button>
</div>
</div>
)
}
function App2() {
const [currentValue, setCurrentValue] = useState(50)
const [queuedValue, setQueuedValue] = useState(50)
const [instantExecutionCount, setInstantExecutionCount] = useState(0)
// Queuer that processes a single value with delays
const [, addItem, queuer] = useQueuedState<number>({
maxSize: 100,
started: true,
wait: 100,
onGetNextItem: (item) => {
setQueuedValue(item)
},
})
function handleRangeChange(e: React.ChangeEvent<HTMLInputElement>) {
const newValue = parseInt(e.target.value, 10)
setCurrentValue(newValue)
setInstantExecutionCount((c) => c + 1)
addItem(newValue)
}
return (
<div>
<h1>TanStack Pacer useQueuedState Example 2</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>
Queued Range (Readonly):
<input
type="range"
min="0"
max="100"
value={queuedValue}
readOnly
style={{ width: '100%' }}
/>
<span>{queuedValue}</span>
</label>
</div>
<table>
<tbody>
<tr>
<td>Queue Size:</td>
<td>{queuer.getSize()}</td>
</tr>
<tr>
<td>Queue Full:</td>
<td>{queuer.getIsFull() ? 'Yes' : 'No'}</td>
</tr>
<tr>
<td>Queue Empty:</td>
<td>{queuer.getIsEmpty() ? 'Yes' : 'No'}</td>
</tr>
<tr>
<td>Queue Idle:</td>
<td>{queuer.getIsIdle() ? 'Yes' : 'No'}</td>
</tr>
<tr>
<td>Queuer Status:</td>
<td>{queuer.getIsRunning() ? 'Running' : 'Stopped'}</td>
</tr>
<tr>
<td>Instant Executions:</td>
<td>{instantExecutionCount}</td>
</tr>
<tr>
<td>Items Processed:</td>
<td>{queuer.getExecutionCount()}</td>
</tr>
<tr>
<td>Saved Executions:</td>
<td>{instantExecutionCount - queuer.getExecutionCount()}</td>
</tr>
<tr>
<td>% Reduction:</td>
<td>
{instantExecutionCount === 0
? '0'
: Math.round(
((instantExecutionCount - queuer.getExecutionCount()) /
instantExecutionCount) *
100,
)}
%
</td>
</tr>
</tbody>
</table>
<div style={{ color: '#666', fontSize: '0.9em' }}>
<p>Queued with 100ms wait time</p>
</div>
</div>
)
}
const root = ReactDOM.createRoot(document.getElementById('root')!)
root.render(
<div>
<App1 />
<hr />
<App2 />
</div>,
)
import ReactDOM from 'react-dom/client'
import { useQueuedState } from '@tanstack/react-pacer/queuer'
import { useState } from 'react'
function App1() {
// Queuer that uses React.useState under the hood
const [queueItems, addItem, queuer] = useQueuedState({
maxSize: 25,
initialItems: [1, 2, 3, 4, 5, 6, 7, 8, 9, 10],
started: false,
wait: 1000, // wait 1 second between processing items - wait is optional!
})
return (
<div>
<h1>TanStack Pacer useQueuedState Example 1</h1>
<div>Queue Size: {queuer.getSize()}</div>
<div>Queue Max Size: {25}</div>
<div>Queue Full: {queuer.getIsFull() ? 'Yes' : 'No'}</div>
<div>Queue Peek: {queuer.getPeek()}</div>
<div>Queue Empty: {queuer.getIsEmpty() ? 'Yes' : 'No'}</div>
<div>Queue Idle: {queuer.getIsIdle() ? 'Yes' : 'No'}</div>
<div>Queuer Status: {queuer.getIsRunning() ? 'Running' : 'Stopped'}</div>
<div>Items Processed: {queuer.getExecutionCount()}</div>
<div>Queue Items: {queueItems.join(', ')}</div>
<div
style={{
display: 'grid',
gridTemplateColumns: 'repeat(2, 1fr)',
gap: '8px',
maxWidth: '600px',
margin: '16px 0',
}}
>
<button
onClick={() => {
const nextNumber = queueItems.length
? queueItems[queueItems.length - 1] + 1
: 1
addItem(nextNumber)
}}
disabled={queuer.getIsFull()}
>
Add Number
</button>
<button
disabled={queuer.getIsEmpty()}
onClick={() => {
const item = queuer.getNextItem()
console.log('getNextItem item', item)
}}
>
Process Next
</button>
<button onClick={() => queuer.clear()} disabled={queuer.getIsEmpty()}>
Clear Queue
</button>
<button onClick={() => queuer.reset()} disabled={queuer.getIsEmpty()}>
Reset Queue
</button>
<button onClick={() => queuer.start()} disabled={queuer.getIsRunning()}>
Start Processing
</button>
<button onClick={() => queuer.stop()} disabled={!queuer.getIsRunning()}>
Stop Processing
</button>
</div>
</div>
)
}
function App2() {
const [currentValue, setCurrentValue] = useState(50)
const [queuedValue, setQueuedValue] = useState(50)
const [instantExecutionCount, setInstantExecutionCount] = useState(0)
// Queuer that processes a single value with delays
const [, addItem, queuer] = useQueuedState<number>({
maxSize: 100,
started: true,
wait: 100,
onGetNextItem: (item) => {
setQueuedValue(item)
},
})
function handleRangeChange(e: React.ChangeEvent<HTMLInputElement>) {
const newValue = parseInt(e.target.value, 10)
setCurrentValue(newValue)
setInstantExecutionCount((c) => c + 1)
addItem(newValue)
}
return (
<div>
<h1>TanStack Pacer useQueuedState Example 2</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>
Queued Range (Readonly):
<input
type="range"
min="0"
max="100"
value={queuedValue}
readOnly
style={{ width: '100%' }}
/>
<span>{queuedValue}</span>
</label>
</div>
<table>
<tbody>
<tr>
<td>Queue Size:</td>
<td>{queuer.getSize()}</td>
</tr>
<tr>
<td>Queue Full:</td>
<td>{queuer.getIsFull() ? 'Yes' : 'No'}</td>
</tr>
<tr>
<td>Queue Empty:</td>
<td>{queuer.getIsEmpty() ? 'Yes' : 'No'}</td>
</tr>
<tr>
<td>Queue Idle:</td>
<td>{queuer.getIsIdle() ? 'Yes' : 'No'}</td>
</tr>
<tr>
<td>Queuer Status:</td>
<td>{queuer.getIsRunning() ? 'Running' : 'Stopped'}</td>
</tr>
<tr>
<td>Instant Executions:</td>
<td>{instantExecutionCount}</td>
</tr>
<tr>
<td>Items Processed:</td>
<td>{queuer.getExecutionCount()}</td>
</tr>
<tr>
<td>Saved Executions:</td>
<td>{instantExecutionCount - queuer.getExecutionCount()}</td>
</tr>
<tr>
<td>% Reduction:</td>
<td>
{instantExecutionCount === 0
? '0'
: Math.round(
((instantExecutionCount - queuer.getExecutionCount()) /
instantExecutionCount) *
100,
)}
%
</td>
</tr>
</tbody>
</table>
<div style={{ color: '#666', fontSize: '0.9em' }}>
<p>Queued with 100ms wait time</p>
</div>
</div>
)
}
const root = ReactDOM.createRoot(document.getElementById('root')!)
root.render(
<div>
<App1 />
<hr />
<App2 />
</div>,
)
Subscribe to Bytes
Your weekly dose of JavaScript news. Delivered every Monday to over 100,000 devs, for free.