Global State Management Library with React

This is a simple yet powerful global state management library built using React's useSyncExternalStore. It allows you to manage global state across multiple components, handle both primitive and object states, and optionally persist the state using localStorage.

Features

• Global State Management: Easily manage state across multiple components without prop drilling.
• Primitive and Object State Support: Handle both primitive types (e.g., numbers, strings) and complex objects.
• State Persistence: Optionally persist state using localStorage with a simple configuration.
• Partial Object Updates: Perform partial updates to object state without overriding the entire object.

Installation

1. Clone the repository:

   git clone https://github.com/codewithwaheed/zorx.git
   cd zorx

2. Install dependencies:

   npm install

Usage

Creating a Store

You can create a global store using the createUseStore function. It supports both primitive and object states and can persist the state to localStorage.

// src/store.ts
import { useSyncExternalStore } from "react";

export type Listener = () => void;

function createStore<T>({
  initialState,
  key,
}: {
  initialState: T;
  key?: string;
}) {
  let subscribers: Listener[] = [];
  let state = initialState;

  // Load persisted state from localStorage
  if (key && typeof window !== "undefined") {
    const persistedState = localStorage.getItem(key);
    if (persistedState) {
      try {
        const parsedState = JSON.parse(persistedState);
        if (typeof parsedState === typeof initialState) {
          state = parsedState;
        }
      } catch (error) {
        console.error("Error parsing state from localStorage", error);
      }
    }
  }

  const notifyStateChanged = () => {
    subscribers.forEach((fn) => fn());
  };

  const persistState = (newState: T) => {
    if (key && typeof window !== "undefined") {
      localStorage.setItem(key, JSON.stringify(newState));
    }
  };

  return {
    subscribe(fn: Listener) {
      subscribers.push(fn);
      return () => {
        subscribers = subscribers.filter((listener) => listener !== fn);
      };
    },
    getSnapshot() {
      return state;
    },
    setState(newState: Partial<T> | T) {
      if (typeof newState === "object" && !Array.isArray(newState)) {
        state = { ...(state as object), ...newState };
      } else {
        state = newState as T;
      }
      notifyStateChanged();
      persistState(state);
    },
  };
}

export function createUseStore<T>(initialState: T, key?: string) {
  const store = createStore({ initialState, key });
  return () =>
    [
      useSyncExternalStore(store.subscribe, store.getSnapshot),
      store.setState,
    ] as const;
}

Example: Managing a Primitive State

For managing a simple primitive state (like a number), create a store and use it inside your component.

// example/globalStore.ts
import { createUseStore } from "../src/store";

export const useCountStore = createUseStore<number>(0, "countState"); // Using localStorage to persist

Then, in your component, you can easily increment or decrement the count:

// example/Counter.tsx
import React from "react";
import { useCountStore } from "./globalStore";

const Counter = ({ index }: { index: number }) => {
  const [count, setCount] = useCountStore();

  const increment = () => setCount(count + 1);
  const decrement = () => setCount(count - 1);

  return (
    <div>
      <h2>
        Counter {index}: {count}
      </h2>
      <button onClick={increment}>Increment</button>
      <button onClick={decrement}>Decrement</button>
    </div>
  );
};

export default Counter;

Example: Managing an Object State

For more complex state management, you can manage an object state and perform partial updates:

// example/globalStore.ts
import { createUseStore } from "../src/store";

interface State {
  count: number;
  user: {
    name: string;
    city: string;
  };
}

export const useGlobalStore = createUseStore<State>(
  {
    count: 0,
    user: {
      name: "Alice",
      city: "Berlin",
    },
  },
  "globalAppState"
);

In your component, you can update only specific properties of the object:

// example/UserComponent.tsx
import React from "react";
import { useGlobalStore } from "./globalStore";

export function UserComponent() {
  const [{ count, user }, setGlobalState] = useGlobalStore();

  const increment = () => {
    setGlobalState({ count: count + 1 });
  };

  const changeCity = () => {
    setGlobalState({ user: { ...user, city: "Hamburg" } }); // Partial update
  };

  return (
    <div>
      <h2>Count: {count}</h2>
      <p>User: {user.name}</p>
      <p>City: {user.city}</p>
      <button onClick={increment}>Increment Count</button>
      <button onClick={changeCity}>Change City</button>
    </div>
  );
}

Running the Example

To run the example:

npm run dev

The example application will start, showcasing the use of both primitive and object-based state management.

Customization

• Initial State: You can pass any initial state to createUseStore — either a primitive or an object.
• Persistence: By providing a key to createUseStore, the state will be automatically persisted in localStorage and restored when the app reloads.

Contributing

Feel free to open issues and submit pull requests for any improvements or bug fixes. Contributions are welcome!

License

This project is licensed under the MIT License.