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createAsyncQueuer

Function: createAsyncQueuer()

ts
function createAsyncQueuer<TValue, TSelected>(
   fn, 
   initialOptions, 
selector): SolidAsyncQueuer<TValue, TSelected>
function createAsyncQueuer<TValue, TSelected>(
   fn, 
   initialOptions, 
selector): SolidAsyncQueuer<TValue, TSelected>

Defined in: async-queuer/createAsyncQueuer.ts:120

Creates a Solid-compatible AsyncQueuer instance for managing an asynchronous queue of items, exposing Solid signals for all stateful properties.

Features:

  • Priority queueing via getPriority or item priority property
  • Configurable concurrency limit
  • FIFO (First In First Out) or LIFO (Last In First Out) queue behavior
  • Pause/resume processing
  • Task cancellation
  • Item expiration
  • Lifecycle callbacks for success, error, settled, items change, etc.
  • All stateful properties (active items, pending items, counts, etc.) are exposed as Solid signals for reactivity

Tasks are processed concurrently up to the configured concurrency limit. When a task completes, the next pending task is processed if the concurrency limit allows.

Error Handling:

  • If an onError handler is provided, it will be called with the error and queuer instance
  • If throwOnError is true (default when no onError handler is provided), the error will be thrown
  • If throwOnError is false (default when onError handler is provided), the error will be swallowed
  • Both onError and throwOnError can be used together; the handler will be called before any error is thrown
  • The error state can be checked using the underlying AsyncQueuer instance

State Management and Selector

The hook uses TanStack Store for reactive state management. The selector parameter allows you to specify which 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 state properties:

  • activeItems: Array of items currently being processed
  • errorCount: Number of items that failed processing
  • isRunning: Whether the queuer is currently running (not stopped)
  • pendingItems: Array of items waiting to be processed
  • rejectionCount: Number of items that were rejected (expired or failed validation)
  • settleCount: Number of items that have completed processing (successful or failed)
  • successCount: Number of items that were processed successfully

Example usage:

tsx
// Default behavior - no reactive state subscriptions
const asyncQueuer = createAsyncQueuer(async (item) => {
  // process item
  return await fetchData(item);
}, {
  initialItems: [],
  concurrency: 2,
  maxSize: 100,
  started: false,
  onSuccess: (result) => {
    console.log('Item processed:', result);
  },
  onError: (error) => {
    console.error('Processing failed:', error);
  }
});

// Opt-in to re-render when queue state changes (optimized for UI updates)
const asyncQueuer = createAsyncQueuer(
  async (item) => await fetchData(item),
  { concurrency: 2, started: true },
  (state) => ({
    pendingItems: state.pendingItems,
    activeItems: state.activeItems,
    isRunning: state.isRunning
  })
);

// Opt-in to re-render when processing metrics change (optimized for tracking progress)
const asyncQueuer = createAsyncQueuer(
  async (item) => await fetchData(item),
  { concurrency: 2, started: true },
  (state) => ({
    successCount: state.successCount,
    errorCount: state.errorCount,
    settleCount: state.settleCount
  })
);

// Add items to queue
asyncQueuer.addItem(newItem);

// Start processing
asyncQueuer.start();

// Access the selected state (will be empty object {} unless selector provided)
const { pendingItems, activeItems } = asyncQueuer.state();
// Default behavior - no reactive state subscriptions
const asyncQueuer = createAsyncQueuer(async (item) => {
  // process item
  return await fetchData(item);
}, {
  initialItems: [],
  concurrency: 2,
  maxSize: 100,
  started: false,
  onSuccess: (result) => {
    console.log('Item processed:', result);
  },
  onError: (error) => {
    console.error('Processing failed:', error);
  }
});

// Opt-in to re-render when queue state changes (optimized for UI updates)
const asyncQueuer = createAsyncQueuer(
  async (item) => await fetchData(item),
  { concurrency: 2, started: true },
  (state) => ({
    pendingItems: state.pendingItems,
    activeItems: state.activeItems,
    isRunning: state.isRunning
  })
);

// Opt-in to re-render when processing metrics change (optimized for tracking progress)
const asyncQueuer = createAsyncQueuer(
  async (item) => await fetchData(item),
  { concurrency: 2, started: true },
  (state) => ({
    successCount: state.successCount,
    errorCount: state.errorCount,
    settleCount: state.settleCount
  })
);

// Add items to queue
asyncQueuer.addItem(newItem);

// Start processing
asyncQueuer.start();

// Access the selected state (will be empty object {} unless selector provided)
const { pendingItems, activeItems } = asyncQueuer.state();

Type Parameters

TValue

TSelected = {}

Parameters

fn

(value) => Promise<any>

initialOptions

AsyncQueuerOptions<TValue> = {}

selector

(state) => TSelected

Returns

SolidAsyncQueuer<TValue, TSelected>

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