react-hooks-global-states 🌟

Effortless global state management for React & React Native & Preact! 🚀 Define a global state in just one line of code and enjoy lightweight, flexible, and scalable state management. Try it now on CodePen and see it in action! ✨

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🔗 Explore More

• Live Example 📘
• Video Overview 🎥
• react-hooks-global-states compatible with both React & React Native
• react-global-state-hooks specific for web applications (local-storage integration).
• react-native-global-state-hooks specific for React Native projects (async-storage integration).

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🚀 React Hooks Global States - DevTools Extension

React Hooks Global States includes a dedicated, devTools extension to streamline your development workflow! Easily visualize, inspect, debug, and modify your application's global state in real-time right within your browser.

🔗 Install the DevTools Extension for Chrome

📸 DevTools Highlights

Track State Changes	Modify the State
Effortlessly monitor state updates and history.	Instantly edit global states directly from the extension.

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Restore the State	Custom Actions Granularity
Quickly revert your application to a previous state.	Precisely debug specific actions affecting state changes.

🛠 Creating a Global State

Define a global state in one line:

import { createGlobalState } from 'react-hooks-global-states/createGlobalState';
export const useCount = createGlobalState(0);

Now, use it inside a component:

const [count, setCount] = useCount();
return <Button onClick={() => setCount((count) => count + 1)}>{count}</Button>;

Works just like useState, but the state is shared globally! 🎉

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🎯 Selectors: Subscribing to Specific State Changes

For complex state objects, you can subscribe to specific properties instead of the entire state:

export const useContacts = createGlobalState({ entities: [], selected: new Set<number>() });

To access only the entities property:

const [contacts] = useContacts((state) => state.entities);
return (
  <ul>
    {contacts.map((contact) => (
      <li key={contact.id}>{contact.name}</li>
    ))}
  </ul>
);

📌 Using Dependencies in Selectors

You can also add dependencies to a selector. This is useful when you want to derive state based on another piece of state (e.g., a filtered list). For example, if you're filtering contacts based on a filter value:

const [contacts] = useContacts(
  (state) => state.entities.filter((item) => item.name.includes(filter)),
  [filter]
);

Alternatively, you can pass dependencies inside an options object:

const [contacts] = useContacts((state) => state.entities.filter((item) => item.name.includes(filter)), {
  dependencies: [filter],
  isEqualRoot: (a, b) => a.entities === b.entities,
});

Unlike Redux, where only root state changes trigger re-selection, this approach ensures that derived values recompute when dependencies change while maintaining performance.

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🔄 Reusing Selectors

📌 Creating a Selector

export const useContactsArray = useContacts.createSelectorHook((state) => state.entities);
export const useContactsCount = useContactsArray.createSelectorHook((entities) => entities.length);

📌 Using Selectors in Components

const [contacts] = useContactsArray();
const [count] = useContactsCount();

✅ Selectors support inline selectors and dependencies

You can still use dependencies inside a selector hook:

const [filteredContacts] = useContactsArray(
  (contacts) => contacts.filter((c) => c.name.includes(filter)),
  [filter]
);

✅ Selector hooks share the same state mutator

The stateMutator remains the same across all derived selectors, meaning actions and setState functions stay consistent.

const [actions1] = useContactsArray();
const [actions2] = useContactsCount();

console.log(actions1 === actions2); // true

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🎛 State Actions: Controlling State Modifications

Restrict state modifications by defining custom actions:

export const useContacts = createGlobalState(
  { filter: '', items: [] },
  {
    actions: {
      async fetch() {
        return async ({ setState }) => {
          const items = await fetchItems();
          setState({ items });
        };
      },
      setFilter(filter: string) {
        return ({ setState }) => {
          setState((state) => ({ ...state, filter }));
        };
      },
    },
  }
);

Now, instead of setState, the hook returns actions:

const [filter, { setFilter }] = useContacts();

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🌍 Accessing Global State Outside Components

Use stateControls() to retrieve or update state outside React components:

const [contactsRetriever, contactsApi] = useContacts.stateControls();
console.log(contactsRetriever()); // Retrieves the current state

✅ Subscribe to changes

const unsubscribe = contactsRetriever((state) => {
  console.log('State updated:', state);
});

✅ Subscriptions are great when one state depends on another.

const useSelectedContact = createGlobalState(null, {
  callbacks: {
    onInit: ({ setState, getState }) => {
      contactsRetriever(
        (state) => state.contacts,
        (contacts) => {
          if (!contacts.has(getState())) setState(null);
        }
      );
    },
  },
});

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🎭 Using Context for Scoped State

• Scoped State – Context state is isolated inside the provider.
• Same API – Context supports selectors, actions, and state controls.

📌 Creating a Context

import { createContext } from 'react-global-state-hooks/createContext';
export const [useCounterContext, CounterProvider] = createContext(0);

Wrap your app:

<CounterProvider>
  <MyComponent />
</CounterProvider>

Use the context state:

const [count] = useCounterContext();

📌 Context Selectors

Works just like global state, but within the provider.

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🔥 Observables: Watching State Changes

Observables let you react to state changes via subscriptions.

📌 Creating an Observable

export const useCounter = createGlobalState(0);
export const counterLogs = useCounter.createObservable((count) => `Counter is at ${count}`);

📌 Subscribing to an Observable

const unsubscribe = counterLogs((message) => {
  console.log(message);
});

📌 Using Observables Inside Context

export const [useStateControls, useObservableBuilder] = useCounterContext.stateControls();
const createObservable = useObservableBuilder();
useEffect(() => {
  const unsubscribe = createObservable((count) => {
    console.log(`Updated count: ${count}`);
  });
  return unsubscribe;
}, []);

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⚖️ createGlobalState vs. createContext

Feature	createGlobalState	createContext
Scope	Available globally across the entire app	Scoped to the Provider where it’s used
How to Use	const useCount = createGlobalState(0)	const [useCountContext, Provider] = createContext(0)
createSelectorHook	useCount.createSelectorHook	useCountContext.createSelectorHook
inline selectors?	✅ Supported	✅ Supported
Custom Actions	✅ Supported	✅ Supported
Observables	useCount.createObservable	const [, useObservableBuilder] = useCountContext.stateControls()
State Controls	useCount.stateControls()	const [useStateControls] = useCountContext.stateControls()
Best For	Global app state (auth, settings, cache)	Scoped module state, reusable component state, or state shared between child components without being fully global

🔄 Lifecycle Methods

Global state hooks support lifecycle callbacks for additional control.

const useData = createGlobalState(
  { value: 1 },
  {
    callbacks: {
      onInit: ({ setState }) => {
        console.log('Store initialized');
      },
      onStateChanged: ({ state, previousState }) => {
        console.log('State changed:', previousState, '→', state);
      },
      computePreventStateChange: ({ state, previousState }) => {
        return state.value === previousState.value;
      },
    },
  }
);

Use onInit for setup, onStateChanged to listen to updates, and computePreventStateChange to prevent unnecessary updates.

Metadata

There is a possibility to add non reactive information in the global state:

const useCount = createGlobalState(0, { metadata: { renders: 0 } });

How to use it?

const [count, , metadata] = useCount();

metadata.renders += 1;

🎯 Ready to Try It?

📦 NPM Package: react-hooks-global-states

🚀 Simplify your global state management in React & React Native today! 🚀