useSignal vs useState

The main difference between using @preact/signals-react and useState is in how the state updates are managed.

With @preact/signals-react, the state is managed using signals and observables, which allows for more granular control over state updates and can help to reduce unnecessary re-renders.

With useState, the state is managed using local state within the component, which can be simpler to use but may lead to more re-renders if the state updates frequently.

Overall, both approaches can be effective for managing state in a React component, and the choice between them may depend on the specific needs of your application.

Benefits of signals

Improved performance

@preact/signals-react leverages a signal-based architecture to manage state, which can help to reduce unnecessary re-renders and improve the performance of your React application. Signals only trigger re-renders when their values change, which can help to optimize the rendering process.

Improved modularity:

Separating your state management code from your component code can make your code more modular and easier to maintain. With @preact/signals-react, you can define signals as the source of truth for your application’s state, and then use those signals to update the state of your components. This can help to improve the overall structure and organization of your code.

Better debugging

@preact/signals-react provides a clear and intuitive way to trace signal dependencies and observe state changes, which can make it easier to debug your application when issues arise. This can be particularly useful in larger or more complex applications where state management can become a challenge.

Better scalability

As your application grows in size and complexity, managing state with useState can become more difficult and error-prone. @preact/signals-react can provide a more scalable solution for managing state, especially in applications with a large number of components or complex state dependencies.

In this example, we define two React components: Counter and CounterWithState. Counter uses useSignal to get the current count value from the countSignal and a setter function to update the count. CounterWithState uses the useState hook to define the current count value and a setter function to update the count. Both components render a button element that displays the current count value and has a click handler that updates the count.

useState

CounterWithState uses the useState hook to define the current count value and a setter function to update the count.

const CounterWithState = () => {
  // Use the useState hook to define the current count value and a setter function
  const [count, setCount] = useState(0);

  // Define a function to handle button clicks and update the count
  const handleClick = () => {
    setCount(count + 1);
  };

  // Return a button element with the current count value and a click handler
  return <button onClick={handleClick}>Count: {count}</button>;
};

useSignal

CounterWithSignal uses useSignal to get the current count value from the countSignal and a setter function to update the count.

import { createSignal } from '@preact/signals';
import { useSignal } from '@preact/signals-react';

// Define a signal for the current count value
const [countSignal, setCountSignal] = createSignal(0);

// Define a React component that uses the countSignal
const CounterWithSignal = () => {
  // Use the countSignal to get the current count value and a setter function
  const [count, setCount] = useSignal(countSignal);

  // Define a function to handle button clicks and update the count
  const handleClick = () => {
    setCount(count + 1);
  };

  // Return a button element with the current count value and a click handler
  return <button onClick={handleClick}>Count: {count}</button>;
};

Conclusion

It’s worth noting that there may be some cases where using useState is still the best option, such as for simple state management or for cases where performance is not a concern. However, in general, using @preact/signals-react can provide a more robust and scalable solution for managing state in React or React applications.