Simple Vuex plugin to keep data across pages

data-persist.js

const persistInterval = 24*60*60*1000; // 1 day

const plugin = store => {
   
    store.subscribe( ( mutation, state ) => {
		
		// Save to local storage all the changes made in the cart state
        if( 'shop/addToCart' === mutation.type || 'shop/removeFromCart' === mutation.type ) {
			let record = { data:  state.shop.cart, ts: new Date().getTime() + persistInterval };
			try {
				localStorage.setItem( 'my_site_cart', JSON.stringify( record ) );
			} catch(e) {}
		}
		
		// When cart is created, get the state from local storage if exists
		if( 'shop/initStore' === mutation.type ) {
			let storage = false;
			try {
				storage = localStorage.getItem( 'my_site_cart' ) || false;
				if( storage ) {
					storage = JSON.parse( storage );
				}
			} catch(e) {}
			
			if( storage && new Date().getTime() < storage.ts ) {
                store.commit( 'shop/setCart', storage.data );
			}
		}
    });
}

export default plugin;