useQueuedValue

Function: useQueuedValue()

function useQueuedValue<TValue, TSelected>(
   initialValue, 
   options, 
   selector?): [TValue, ReactQueuer<TValue, TSelected>]

function useQueuedValue<TValue, TSelected>(
   initialValue, 
   options, 
   selector?): [TValue, ReactQueuer<TValue, TSelected>]

Defined in: react-pacer/src/queuer/useQueuedValue.ts:103

A React hook that creates a queued value that processes state changes in order with an optional delay. This hook uses useQueuer internally to manage a queue of state changes and apply them sequentially.

The queued value will process changes in the order they are received, with optional delays between processing each change. This is useful for handling state updates that need to be processed in a specific order, like animations or sequential UI updates.

The hook returns a tuple containing:

The current queued value
The queuer instance with control methods

State Management and Selector

The hook uses TanStack Store for reactive state management via the underlying queuer instance. The selector parameter allows you to specify which queuer state changes will trigger a re-render, optimizing performance by preventing unnecessary re-renders when irrelevant state changes occur.

By default, there will be no reactive state subscriptions and you must opt-in to state tracking by providing a selector function. This prevents unnecessary re-renders and gives you full control over when your component updates. Only when you provide a selector will the component re-render when the selected state values change.

Available queuer state properties:

executionCount: Number of items that have been processed by the queuer
expirationCount: Number of items that have been removed due to expiration
isEmpty: Whether the queuer has no items to process
isFull: Whether the queuer has reached its maximum capacity
isIdle: Whether the queuer is not currently processing any items
isRunning: Whether the queuer is active and will process items automatically
items: Array of items currently waiting to be processed
itemTimestamps: Timestamps when items were added for expiration tracking
pendingTick: Whether the queuer has a pending timeout for processing the next item
rejectionCount: Number of items that have been rejected from being added
size: Number of items currently in the queue
status: Current processing status ('idle' | 'running' | 'stopped')

// Default behavior - no reactive state subscriptions
const [value, queuer] = useQueuedValue(initialValue, {
  wait: 500, // Wait 500ms between processing each change
  started: true // Start processing immediately
});

// Opt-in to re-render when queue processing state changes (optimized for loading indicators)
const [value, queuer] = useQueuedValue(
  initialValue,
  { wait: 500, started: true },
  (state) => ({
    isRunning: state.isRunning,
    isIdle: state.isIdle,
    status: state.status,
    pendingTick: state.pendingTick
  })
);

// Opt-in to re-render when queue contents change (optimized for displaying queue status)
const [value, queuer] = useQueuedValue(
  initialValue,
  { wait: 500, started: true },
  (state) => ({
    size: state.size,
    isEmpty: state.isEmpty,
    isFull: state.isFull
  })
);

// Opt-in to re-render when execution metrics change (optimized for stats display)
const [value, queuer] = useQueuedValue(
  initialValue,
  { wait: 500, started: true },
  (state) => ({
    executionCount: state.executionCount,
    expirationCount: state.expirationCount,
    rejectionCount: state.rejectionCount
  })
);

// Add changes to the queue
const handleChange = (newValue) => {
  queuer.addItem(newValue);
};

// Control the queue
const pauseProcessing = () => {
  queuer.stop();
};

const resumeProcessing = () => {
  queuer.start();
};

// Access the selected queuer state (will be empty object {} unless selector provided)
const { size, isRunning, executionCount } = queuer.state;

// Default behavior - no reactive state subscriptions
const [value, queuer] = useQueuedValue(initialValue, {
  wait: 500, // Wait 500ms between processing each change
  started: true // Start processing immediately
});

// Opt-in to re-render when queue processing state changes (optimized for loading indicators)
const [value, queuer] = useQueuedValue(
  initialValue,
  { wait: 500, started: true },
  (state) => ({
    isRunning: state.isRunning,
    isIdle: state.isIdle,
    status: state.status,
    pendingTick: state.pendingTick
  })
);

// Opt-in to re-render when queue contents change (optimized for displaying queue status)
const [value, queuer] = useQueuedValue(
  initialValue,
  { wait: 500, started: true },
  (state) => ({
    size: state.size,
    isEmpty: state.isEmpty,
    isFull: state.isFull
  })
);

// Opt-in to re-render when execution metrics change (optimized for stats display)
const [value, queuer] = useQueuedValue(
  initialValue,
  { wait: 500, started: true },
  (state) => ({
    executionCount: state.executionCount,
    expirationCount: state.expirationCount,
    rejectionCount: state.rejectionCount
  })
);

// Add changes to the queue
const handleChange = (newValue) => {
  queuer.addItem(newValue);
};

// Control the queue
const pauseProcessing = () => {
  queuer.stop();
};

const resumeProcessing = () => {
  queuer.start();
};

// Access the selected queuer state (will be empty object {} unless selector provided)
const { size, isRunning, executionCount } = queuer.state;

useQueuedValue

Function: useQueuedValue()

State Management and Selector

Type Parameters

Parameters

initialValue

options

selector?

Returns

Example

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