untracked

/**
 * @param fn The function to execute without tracking signal dependencies
 * @returns The result of the function execution
 */
untracked<T>(fn: () => T): T

Allows you to access signal values without creating dependencies. It’s useful when you need to read a signal’s value within an effect or computed value without causing that effect to re-run when the signal changes.

Basic Usage

import { signal, effect, untracked } from '@hellajs/core';

const count = signal(0);
const threshold = signal(10);

effect(() => {
  // This will create a dependency on count
  const currentCount = count();

  // This will NOT create a dependency on threshold
  const currentThreshold = untracked(() => threshold());

  console.log(`Count: ${currentCount}, Threshold: ${currentThreshold}`);
});

// Effect runs, logs: "Count: 0, Threshold: 10"

count.set(1);
// Effect runs, logs: "Count: 1, Threshold: 10"

threshold.set(20);
// Effect doesn't run, since threshold was read via untracked

Conditional Tracking Example

import { signal, computed, untracked } from '@hellajs/core';

const items = signal([1, 2, 3, 4]);
const config = signal({ shouldFilter: true, threshold: 3 });

const filteredItems = computed(() => {
  const list = items();

  // Only track config.shouldFilter, not the whole config object
  const shouldFilter = config().shouldFilter;

  if (shouldFilter) {
    // Don't track threshold changes
    const threshold = untracked(() => config().threshold);
    return list.filter(item => item <= threshold);
  }

  return list;
});