CODE EXAMPLE FOR JAVASCRIPT

useContext from localhost

import React,{useState, createContext} from 'react';

export const ProductsContext = createContext();

export const ProductsProvider = props => {
    const [categories, setCategories] = useState({ categories: {} });
    const [products, setProducts] = useState({ products: {} });
    const [loading, setLoading] = useState(true);
    useEffect(() => {
        (async () => {
            const [categoriesResult, productsResult] = await Promise.all([fetch('http://localhost:3000/api/categories'), fetch('http://localhost:3000/api/products')]);
            setCategories(categoriesResult);
            setProducts(productsResult);
            setLoading(false);
          })();
        }, []);
    return (
    <ProductsContext.Provider value={ { products, categories, loading } }>
        {props.children}
    </ProductsContext.Provider>
    );
}