Optimizing State Updates with Batching in SolidJS

The Problem with Individual State Updates

In traditional reactive systems, each individual state change triggers a re-render of the UI. This can lead to redundant operations and decreased performance. For instance, consider a simple form with two input fields that update two separate signals. When the form is submitted, each signal’s value is updated individually, triggering multiple UI updates and effects.

Introducing Batching in SolidJS

SolidJS provides a built-in batch function that enables developers to manually batch state updates. By wrapping related state updates within a batch call, developers can delay UI updates until all values are changed. This approach reduces the number of times effects are run, resulting in more efficient code.

Using Batch in SolidJS

To demonstrate the power of batching, let’s consider an example where we have two signals, p1 and p2, displayed in the UI as h1 elements. We create an effect that logs both values to the console when either value changes. Without batching, each individual state update triggers a separate UI update and effect.

import { createSignal, batch } from 'olid-js';

const [p1, setP1] = createSignal('Initial value 1');
const [p2, setP2] = createSignal('Initial value 2');

// Create an effect that logs both values to the console
createEffect(() => {
  console.log(`p1: ${p1()}, p2: ${p2()}`);
});

// Without batching
setP1('Bread');
setP2('Cheese');

// With batching
batch(() => {
  setP1('Bread');
  setP2('Cheese');
});

By wrapping the state updates within a batch call, we delay the UI updates until both values are changed. This results in a single console log and improved performance.

When to Use Batch

Batching is particularly useful when updating multiple unique signals that depend on each other. By delaying UI updates until all values are changed, developers can prevent redundant operations and improve overall application performance.

• Update multiple signals that depend on each other
• Avoid redundant operations and effects
• Improve overall application performance

By leveraging batching and other optimization techniques, developers can build faster, more responsive, and more scalable applications.