Nuxt Cache

A flexible caching solution for Nuxt 3 that provides both in-memory and persistent storage caching strategies.

Features

• 🧠 useMemoryCache: In-memory caching with Nuxt's payload system
• 💾 useStorageCache: Persistent caching using localStorage
• 🔗 MemoryLink: Auto-prefetching NuxtLink component with in-memory caching
• 📍 StorageLink: Auto-prefetching NuxtLink component with persistent storage caching
• 🧩 useSmartLinks: Centralised management of URL and cache settings for SmartLinks
• ⚡️ Zero-config setup with sensible defaults
• 🎯 Full TypeScript support
• 🔄 Compatible with useFetch, useLazyFetch, and custom fetch composables
• 💪 Built on top of VueUse's useStorage for persistent caching

Installation

npm install @crbroughton/nuxt-cache

1. Add @crbroughton/nuxt-cache to the modules section of your nuxt.config.ts:

export default defineNuxtConfig({
  modules: [
    '@crbroughton/nuxt-cache'
  ],
})

Usage

Both the memory and persistent variants of nuxt-cache come with two flavours of caching. The first is designed for simple API interactions, where you do not require tranforming the data. These are:

• useMemoryCache
• useStorageCache

When transformation is required, two sets of level level caching functions are exposed:

• createMemoryHandler and createMemoryCache for memory caching
• createStorageHandler and createStorageCache for persistent caching

Memory Cache

Uses Nuxt's built-in payload system to cache data in memory. Ideal for server-side rendered data that doesn't need to persist.

// Basic usage
const { data } = await useFetch<MemoryCache<Product[]>>('/api/products', {
  {
  // other useFetch options
  ...useMemoryCache({ duration: 3600000 }) // Cache for 1 hour
  }
})

// With lazy loading
const { data } = await useLazyFetch<MemoryCache<Product[]>>('/api/products', {
  {
  // other useFetch options
  ...useMemoryCache({ duration: 3600000 })
  }
})

When requiring transformation of a response before exposing the response through useFetch, you can use the createMemoryHandler and createMemoryCache helpers.

const { data, status, error } = await useFetch(
  'https://fakestoreapi.com/products',
  {
    transform(input: Product[]) { // Need to manually declare the type here
      const modifiedProducts = input.map(product => ({
        id: product.id,
        title: product.title,
        price: product.price,
      }))
      return createMemoryHandler(modifiedProducts)
    },
    getCachedData(key, nuxtApp) {
      return createMemoryCache({
        key,
        nuxtApp,
        duration: 5000,
      })
    },
  },
)

Caveats of Memory Caching

Because in memory caching has no persistent store, we need to return both the data and the fetchedAt date back to the user to verify when a cached payload has gone out-of-date.

Because of this, we highly recommend using the MemoryCache type as a wrapper around your return type when using useFetch. This will ensure when accessing the returned data, that you are acting on the correct shape. The interface is as follows:

export interface MemoryCache<T> {
  data: T
  fetchedAt: Date
}

The above type is readily available via @crbroughton/nuxt-cache and has been exported for you to use.

Storage Cache

Uses localStorage to persist cached data between page reloads. Perfect for client-side data that should survive browser refreshes. Because the storage cache is persisent, we only need to return to you your actual data, and no fetchedAt date.

// Basic usage
const { data } = await useFetch<Product[]>('/api/products', {
  useStorageCache({ 
    duration: 3600000, // Cache for 1 hour
    key: 'products' // Optional custom key
  })
})

// With lazy loading
const { data } = await useLazyFetch<Product[]>('/api/products', {
  useStorageCache({ duration: 3600000 })
})

When requiring transformation of a response before exposing the response through useFetch, you can use the createStorageHandler and createStorageCache helpers.

type MinimalProduct = Pick<Product, 'id' | 'title' | 'price'>
const CACHE_KEY = '__storage_cache__/products'
const { data, status, error } = await useFetch<MinimalProduct[]>(
  'https://fakestoreapi.com/products',
  {
    transform(input) {
      const modifiedProducts = input.map(product => ({
        id: product.id,
        title: product.title,
        price: product.price,
      }))
      return createStorageHandler({
        storageKey: CACHE_KEY,
        data: modifiedProducts,
      })
    },
    getCachedData(key, nuxtApp) {
      return createStorageCache({
        key,
        nuxtApp,
        storageKey: CACHE_KEY,
        duration: 10000,
      })
    },
  },
)

Smart Link Components

You may also wish to fetch data before the user has ever navigated to a page; The package provides two smart link components that automatically prefetch API data when users hover or interact with links, optimizing the navigation experience:

MemoryLink (Memory Cache)

Extends NuxtLink to prefetch and cache API data in memory:

<MemoryLink 
  to="/products"
  url="https://api.example.com/products"
  cacheKey="products-list"
  :cacheDuration="5000"
>
  View Products
</MemoryLink>

Then in your target page:

const { data } = await useFetch<MemoryCache<Product[]>>(
  'https://api.example.com/products',
  {
    ...useMemoryCache({ duration: 5000 }),
    key: 'products-list' // Match the cacheKey from SmartLink
  }
)

StorageLink (Persistent Cache)

Similar to MemoryLink but with persistent storage using localStorage:

<StorageLink 
  to="/products"
  url="https://api.example.com/products"
  cacheKey="products-list"
  :cacheDuration="5000"
>
  View Products
</StorageLink>

Then in your target page:

const { data } = await useFetch<Product[]>(
  'https://api.example.com/products',
  {
    ...useStorageCache({ 
      duration: 5000,
      key: 'products-list' // Match the cacheKey from SmartStorageLink
    })
  }
)

Both components:

• Prefetch data on hover
• Cache the response for the specified duration
• Prevent duplicate API calls when navigating
• Check cache validity before making new requests
• Handle loading states to prevent multiple simultaneous requests

Smart Links Management

The defineSmartLinks helper provides a centralised way to manage URLs and cache settings for your application's smart links. This helper exposes provideSmartLinks and useSmartLinks for easy access to your smart links.

Setting up SmartLinks

First, provide your smart links in a parent component:

import { provideSmartLinks } from '@crbroughton/nuxt-cache'

// In your parent component
provideSmartLinks({
  products: {
    url: 'https://api.example.com/products',
    cacheKey: 'products-cache',
    cacheDuration: 5000 // 5 seconds
  },
  settings: {
    url: 'https://api.example.com/settings',
    cacheKey: 'settings-cache',
    cacheDuration: 3600000 // 1 hour
  }
})

Using SmartLinks in components

Then use these smart links throughout your application:

import { useSmartLinks } from '@crbroughton/nuxt-cache'

// In any component
const { getSmartLink } = useSmartLinks<typeof smartLinks>() // provide the type of your smartlinks

// Get properties for a specific smart link
const productsLink = getSmartLink('products')
console.log(productsLink.url) // https://api.example.com/products
console.log(productsLink.cacheDuration) // 5000

// Get just the cache key for use with MemoryLink or StorageLink
const productsCacheKey = smartLinks.getCacheKey('products') // 'products'

// Get just the URL for a fetch call
const productsUrl = smartLinks.getCacheUrl('products') // 'https://api.example.com/products'

Using with SmartLink components

SmartLinks pairs perfectly with the MemoryLink and StorageLink components:

<template>
  <div>
    <!-- Using the built in helpers that provideSmartLink exports -->
    <MemoryLink 
      to="/products"
      :url="getCacheUrl('products')"
      :cacheKey="getCacheKey('products')"
      :cacheDuration="getSmartLink('products').cacheDuration"
    >
      View Products
    </MemoryLink>
    <!-- Using v-bind-->
    <MemoryLink 
      to="/products"
      v-bind="getSmartLink('products')"
    >
      View Products
    </MemoryLink>
  </div>
</template>

<script setup>
import { useSmartLinks } from '@crbroughton/nuxt-cache'

const { getCacheUrl, getCacheKey, getSmartLink } = useSmartLinks()
</script>

This approach provides type-safe access to your API endpoints and cache settings, making it easier to maintain consistent caching behaviour across your application.

How It Works

Memory Cache

• Uses Nuxt's payload system to store data in memory
• Data persists only for the current session
• Automatically cleared on page refresh

Storage Cache

• Uses localStorage through VueUse's useStorage
• Data persists between page reloads
• Automatically handles JSON serialization/deserialization
• Includes timestamp checking for cache invalidation

SmartLinks

• Provides a centralized store for managing API endpoints and cache settings
• Type-safe access to URLs and cache configuration
• Simplifies the use of MemoryLink and StorageLink components
• Helps maintain consistent caching behavior across your application

Contributing

1. Clone this repository
2. Install dependencies using bun install
3. Run development server using bun dev
4. Create a PR with your changes

License

MIT License