Simplifying State Management in React Native with Zustand

npm install zustand

yarn add zustand

import create from 'zustand';

// Create the store
const myStore1 = create((set, get) => ({
    items: [], // Initial state

    // Action to fetch items from an API
    fetchItems: async () => {
        try {
            const response = await fetch('https://api.example.com/items'); // Replace with your API URL
            const data = await response.json();
            set({ items: data });
        } catch (error) {
            console.error('Failed to fetch items:', error);
        }
    },

    // Action to add an item
    addItem: (item) => set((state) => ({
        items: [...state.items, item],
    })),

    // Action to remove an item
    removeItem: (id) => set((state) => ({
        items: state.items.filter(item => item.id !== id),
    })),

    // Action to get the count of items
    getItemCount: () => get().items.length,
}));

export default myStore1;

import React, { useEffect } from 'react';
import { View, Text, Button, FlatList, StyleSheet } from 'react-native';
import myStore1 from './myStore1'; // Adjust the path to where your store file is located

const App = () => {
    // Destructure actions and state from the store
    const { items, fetchItems, addItem, removeItem, getItemCount } = myStore1();

    // Fetch items when the component mounts
    useEffect(() => {
        fetchItems();
    }, [fetchItems]);

    const handleAddItem = () => {
        const newItem = { id: Date.now(), name: 'New Item' };
        addItem(newItem);
    };

    const handleRemoveItem = (id) => {
        removeItem(id);
    };

    return (
        <View style={styles.container}>
            <Text style={styles.header}>Item List ({getItemCount()})</Text>
            <Button title="Add Item" onPress={handleAddItem} />
            <FlatList
                data={items}
                keyExtractor={(item) => item.id.toString()}
                renderItem={({ item }) => (
                    <View style={styles.item}>
                        <Text>{item.name}</Text>
                        <Button title="Remove" onPress={() => handleRemoveItem(item.id)} />
                    </View>
                )}
            />
        </View>
    );
};

const styles = StyleSheet.create({
    container: {
        flex: 1,
        padding: 16,
    },
    header: {
        fontSize: 24,
        marginBottom: 16,
    },
    item: {
        flexDirection: 'row',
        justifyContent: 'space-between',
        padding: 16,
        borderBottomWidth: 1,
        borderBottomColor: '#ccc',
    },
});

export default App;

import AsyncStorage from '@react-native-async-storage/async-storage';
import { create } from 'zustand';
import { persist, createJSONStorage } from 'zustand/middleware';

// Create the store
export const useScansStore = create()(
    persist(
        (set, get) => ({
            fishes: 0, // Initial state
            addAFish: () => set({ fishes: get().fishes + 1 }) // Function to update state
        }),
        {
            name: "food-storage", // Key used to store the data
            storage: createJSONStorage(() => AsyncStorage), // Use AsyncStorage for persistence
        }
    )
);

import { MMKV } from "react-native-mmkv";

export const storage = new MMKV({
    id: 'my-app-storage',
    encryptionKey: 'some_encryption_key'
})

export const mmkvStorage = {
    setItem: (key, value) => {
        storage.set(key, value)
    },
    getItem: (key) => {
        const value = storage.getString(key)
        return value ?? null
    },
    removeItem: (key) => {
        storage.delete(key)
    },
}

import { create } from 'zustand';
import { persist, createJSONStorage } from 'zustand/middleware';
import mmkvStorage from './mmkvStorage'; // Import the MMKV storage configuration

// Create the store
export const useScansStore = create()(
    persist(
        (set, get) => ({
            fishes: 0, // Initial state
            addAFish: () => set({ fishes: get().fishes + 1 }) // Function to update state
        }),
        {
            name: "food-storage", // Key used to store the data
            storage: createJSONStorage(() => mmkvStorage), // Use MMKV for persistence
        }
    )
);