Object-Based UI State Management vs. JavaScript Proxy-Based UI State Management
Published: 2024-07-13 02:33:56

State management is a critical aspect of modern UI development, especially as applications grow in complexity. Two popular methods for managing UI state in JavaScript applications are object-based UI state management and proxy-based UI state management. Both approaches have their advantages and trade-offs. This article delves into these two methodologies, comparing their concepts, implementation, and practical use cases, using Redux and Zustand as examples.

**Object-Based UI State Management:**

Object-based state management involves managing the state using plain JavaScript objects. This method typically leverages libraries like Redux, MobX, or even the Context API in React. The core idea is to have a central store (an object) that holds the application’s state, and components subscribe to changes in this state.

**Key Characteristics:**

**Centralized Store:** State is stored in a single or a few central objects.
**Immutable Updates:** State updates are performed immutably. Instead of modifying the existing state, a new state object is created and replaced.

**Action-Based Changes:** State changes are triggered by dispatching actions (in libraries like Redux), which describe the changes to be made.

**Selectors:** Functions that derive specific pieces of state from the central store, allowing components to subscribe to only the data they need.

**Advantages:**

**Predictability:** Clear flow of data and state transitions make it easy to reason about the state changes.

**Debugging:** Tools like Redux DevTools provide powerful debugging capabilities, showing the state before and after each action.

**Testing:** The separation of actions and reducers (or similar constructs) facilitates easier unit testing.
Disadvantages:

**Boilerplate Code:** Often involves writing more code (actions, reducers, selectors), which can be verbose and cumbersome.

**Performance:** Frequent state updates can lead to performance bottlenecks if not managed properly, especially in large applications.

<u>Example with Redux:</u>

**Redux Code Sample
1)Installation:**

```
npm install redux react-redux
```

**2. Defining Actions:**
```
// actions.js
export const INCREMENT = 'INCREMENT';
export const DECREMENT = 'DECREMENT';

export const increment = () => ({
  type: INCREMENT
});

export const decrement = () => ({
  type: DECREMENT
});
```

**3. Creating Reducers:**
```
// reducers.js
import { INCREMENT, DECREMENT } from './actions';

const initialState = {
  count: 0
};
const counterReducer = (state = initialState, action) => {
  switch (action.type) {
    case INCREMENT:
      return { ...state, count: state.count + 1 };
    case DECREMENT:
      return { ...state, count: state.count - 1 };
    default:
      return state;
  }
};
export default counterReducer;
```

**4. Setting Up the Store**
```
// store.js
import { createStore } from 'redux';
import counterReducer from './reducers';

const store = createStore(counterReducer);
export default store;
```

**5. Connecting React Components**
```
// App.js
import React from 'react';
import { Provider, useSelector, useDispatch } from 'react-redux';
import store from './store';
import { increment, decrement } from './actions';

const Counter = () => {
  const count = useSelector(state => state.count);
  const dispatch = useDispatch();
  return (
    <div>
      <p>Count: {count}</p>
      <button onClick={() => dispatch(increment())}>Increment</button>
      <button onClick={() => dispatch(decrement())}>Decrement</button>
    </div>
  );
};
const App = () => (
  <Provider store={store}>
    <Counter />
  </Provider>
);
export default App;
```

**Proxy-Based UI State Management**

Proxy-based state management leverages the Proxy object in JavaScript, which allows for the creation of objects with custom behavior for fundamental operations like getting and setting properties. Libraries like Vue 3 (with its Composition API and reactive system) and Immer use Proxies to achieve reactivity and immutability.

**Key Characteristics:**

**Reactive State:** State is made reactive by wrapping objects in a Proxy, which intercepts operations and triggers updates.

**Transparent Mutations:** State can be mutated directly, and the Proxy ensures that the changes are tracked and propagated.

**Minimal Boilerplate:** Direct mutations reduce the need for boilerplate code, making the development process more straightforward.

**Advantages:**

**Simplicity:** Allows for direct state mutations, reducing the need for boilerplate code.

**Reactivity:** Automatically tracks dependencies and updates, providing a responsive UI without manual subscription management.

**Performance:** Efficiently tracks and updates only the parts of the state that change.

**Disadvantages:**

**Complexity in Debugging:** Debugging can be more challenging due to the implicit nature of reactivity.

**Learning Curve:** Understanding Proxies and their behavior can be more difficult for developers unfamiliar with this concept.

**Example with Valtio Composition API:**

**1. Valtio Code Sample**
Installation
```
npm install valtio
```

**2. Creating State**
```
// state.js
import { proxy } from 'valtio';

const state = proxy({
  count: 0
});
export default state;
```

**3. Creating Actions**
```
// actions.js
import state from './state';

export const increment = () => {
  state.count += 1;
};
export const decrement = () => {
  state.count -= 1;
};
```

**4. Connecting React Components**
```
// App.js
import React from 'react';
import { useSnapshot } from 'valtio';
import state, { increment, decrement } from './state';

const Counter = () => {
  const snap = useSnapshot(state);
  return (
    <div>
      <p>Count: {snap.count}</p>
      <button onClick={increment}>Increment</button>
      <button onClick={decrement}>Decrement</button>
    </div>
  );
};
const App = () => <Counter />;
export default App;
```

**Comparison and Use Cases**

**Predictability and Debugging:**

- Object-based state management offers better predictability and easier debugging with tools like Redux DevTools.

- Proxy-based state management can be less predictable due to the implicit reactivity, making debugging more complex.
Boilerplate and Development Speed:


- Object-based state management often requires more boilerplate code, which can slow down development.

- Proxy-based state management simplifies the code by allowing direct mutations, speeding up the development process.

**Performance:**

Both methods can be performant if used correctly. Object-based management can suffer from performance issues if the state tree is large and frequently updated.

 - Proxy-based management can provide efficient updates by tracking only the necessary state changes.
Learning Curve:

 - Object-based state management may be easier for developers familiar with traditional Redux-like patterns.

 - Proxy-based state management, while powerful, requires understanding Proxies and reactive patterns, which can have a steeper learning curve.

**Use Cases:**

**Object-Based:** Ideal for applications where state transitions need to be explicitly managed and debugged, such as complex enterprise applications.

**Proxy-Based:** Suitable for applications where ease of state management and reactivity are prioritized, such as real-time data dashboards or interactive interfaces.

**Conclusion**
Both Redux and Valtio offer powerful state management solutions with distinct advantages. Redux excels in predictability and tooling for complex applications, while Valtio provides simplicity and automatic reactivity for straightforward state management. Choosing the right tool depends on your application’s needs and your team’s familiarity with the respective libraries.