Nuxt•4w ago

dumb question: cache usage with useFetch

Hey guys - I couldn't find the answer in the official docs. What is the correct way to cache API responses based on keys ? I understand that passing a key is to de-duplicate requests between server/side rendering, but I thought it alone would be enough to cache requests - to avoid hitting the API and instead grab from disk cache. Apparently I need to pass a cache key - is that it ? Indeed I need to force cache whenever I need to ? Thanks in advance brothers.

const { data: response, error } = await useFetch(
      '/api/...',
      {
        method: 'GET',
        cache: 'force-cache',
        key: 'my-key-here',
      }
    )

const { data: response, error } = await useFetch(
      '/api/...',
      {
        method: 'GET',
        cache: 'force-cache',
        key: 'my-key-here',
      }
    )

14 Replies

kapa.ai•4w ago

Hi @lpmagal. I'm kapa.ai, your friendly support bot. I will try to answer your question by searching through the knowledge base. :wave: ---------------------- Your question about caching with useFetch in Nuxt is not dumb at all. It's a common area of confusion. Let me clarify this for you based on the available information. 1. Key Usage: You're correct that the key parameter is primarily used for de-duplication of requests, especially between server-side and client-side rendering. However, it's not sufficient alone for caching API responses on the client-side across page reloads or revisits Docs > Getting-started > Data fetching > Keys (https://nuxt.com/docs/getting-started/data-fetching#keys). 2. Cache Option: The cache option you're using is indeed part of the solution, but it works slightly differently than you might expect. The cache option is passed directly to the underlying fetch API and affects how the browser handles the HTTP request caching Docs > Api > Composables > useFetch (https://nuxt.com/docs/api/composables/use-fetch#params). It doesn't directly control Nuxt's internal caching mechanism. 3. Correct Usage: To properly cache API responses in Nuxt, you should use a combination of approaches: a. Use the key parameter for request de-duplication. b. Utilize the getCachedData option for custom caching logic. c. Consider using useNuxtData for accessing cached data across components. Here's an example of how you might set this up:

const { data: response, error } = await useFetch('/api/...', {
  method: 'GET',
  key: 'my-key-here',
  getCachedData: (key) => {
    // Implement your custom caching logic here
    // For example, you could use localStorage or another caching mechanism
    return JSON.parse(localStorage.getItem(key))
  }
})

const { data: response, error } = await useFetch('/api/...', {
  method: 'GET',
  key: 'my-key-here',
  getCachedData: (key) => {
    // Implement your custom caching logic here
    // For example, you could use localStorage or another caching mechanism
    return JSON.parse(localStorage.getItem(key))
  }
})

4. Additional Considerations: - The cache: 'force-cache' option you're using is actually not a standard option for the Fetch API. The correct values are 'default', 'no-store', 'reload', 'no-cache', 'force-cache', or 'only-if-cached' Docs > Api > Composables > useFetch (https://nuxt.com/docs/api/composables/use-fetch#params). - For client-side caching across page reloads, you might need to implement a custom caching strategy using getCachedData and possibly localStorage or another client-side storage mechanism. 5. Nuxt 3.8 Update: As of Nuxt 3.8, there's a new feature called getCachedData which allows for more control over caching, including the ability to implement custom Time-To-Live (TTL) logic for cached data YouTube: Nuxt 3.8 - Client-side caching with getCachedData (https://www.youtube.com/watch?v=aQPR0xn-MMk). Remember, the exact caching strategy you should use depends on your specific use case, including considerations like data freshness requirements and user experience. ---------------------- Note: you can ask me a follow up question by @ mentioning me again :speech_balloon: ----------------------

kapa.ai•4w ago

<@301830740675526657> Kapa.ai is still learning and improving, please let me know how I did by reacting below.

lpmagalOP•3w ago

// @kapa.ai I really thought that we would have a native caching solution - that didn't require us to manually type how to cache. I.E:

const { data: response, error } = await useFetch(
      '/api/...',
      {
        method: 'GET',
        key: 'my-key-here',
      }
    )

const { data: response, error } = await useFetch(
      '/api/...',
      {
        method: 'GET',
        key: 'my-key-here',
      }
    )

Calling this 1st time would fire the API request. Calling this the 2nd time would load from cache. I believe then there is no such thing - I mean, cache automatically without having to set up a method (like localStorage or pinia) ?

kapa.ai•3w ago

Let me check the knowledge base for you again. One moment! :books: ---------------------- You're right in your understanding, and I apologize if my previous answer wasn't clear enough. Let me clarify the current state of caching in Nuxt based on the latest information available. Nuxt does indeed have a native caching solution that works similarly to what you described, but it's important to understand how it functions: 1. Default Caching Behavior: By default, useFetch does cache data based on the key parameter. When you use useFetch with a key, Nuxt will automatically cache the result Docs > Getting-started > Data fetching > Keys (https://nuxt.com/docs/getting-started/data-fetching#keys). 2. How It Works: - The first time the useFetch call is made, it will fire the API request. - On subsequent calls with the same key, it will return the cached data without making a new API request. 3. Caching Scope: However, this automatic caching is primarily designed for the duration of a single page load or server-side render. It doesn't persist across page reloads or browser sessions by default. 4. Recent Updates: As of Nuxt 3.8, there have been improvements to the caching system. The getCachedData option was introduced to allow for more control over caching, including the ability to implement custom caching strategies YouTube: Nuxt 3.8 - Client-side caching with getCachedData (https://www.youtube.com/watch?v=aQPR0xn-MMk). 5. Example of Default Behavior: Your example is correct for the default behavior within a single page load:

const { data: response, error } = await useFetch('/api/...', {
  method: 'GET',
  key: 'my-key-here',
})

const { data: response, error } = await useFetch('/api/...', {
  method: 'GET',
  key: 'my-key-here',
})

This will cache the result automatically for the duration of the page's lifecycle. 6. Limitations: The native caching solution doesn't automatically persist data across page reloads or browser sessions. For that level of persistence, you would indeed need to implement a custom solution using localStorage, pinia, or other state management tools. 7. Custom Persistence: If you need data to persist across page reloads, you might consider using the getCachedData option to implement a custom caching strategy, as mentioned in the Nuxt 3.8 update GitHub PR: feat(nuxt): custom cache support for data fetching composables (https://github.com/nuxt/nuxt/pull/20747). In conclusion, while Nuxt does offer automatic caching within a page's lifecycle, persistent caching across sessions or page reloads still requires some custom implementation. The framework provides tools to make this easier, but it doesn't automatically handle all caching scenarios out of the box to allow for flexibility in different use cases. ---------------------- Note: you can ask me a follow up question by @ mentioning me again :speech_balloon: ----------------------

kapa.ai•3w ago

<@301830740675526657> Kapa.ai is still learning and improving, please let me know how I did by reacting below.

lpmagalOP•3w ago

/// @kapa.ai Hm, right. I have an use case that's causing questions on my head. I have the "/" page and "/wathever-page". As soon I enter the "/" page, the component will fire that API request as mentioned above. I would like that when navigating to "wathever" page and coming back to "/", as soon as the component mounts, to not fire the API but the cache - since I didnt need to invalidate that data. I just wanted to spare some requests - using the cache. What would be the best approach ?

kapa.ai•3w ago

Let me check the knowledge base for you again. One moment! :books: ---------------------- Your use case is a common scenario in web applications, and Nuxt provides some built-in features to handle this efficiently. Let's explore the best approach based on the information available: 1. Shared Prerender Data: Nuxt 3 has introduced a feature called "Shared Prerender Data" which automatically shares payload data between pages that are prerendered. This can significantly improve performance when using useAsyncData or useFetch to fetch the same data on different pages Docs > Guide > Going-further > Experimental Features > sharedPrerenderData (https://nuxt.com/docs/guide/going-further/experimental-features#sharedprerenderdata). 2. Using useNuxtData: For client-side navigation, you can leverage the useNuxtData composable to access cached data across components and pages. This allows you to reuse data that has already been fetched Docs > Api > Composables > useNuxtData (https://nuxt.com/docs/api/composables/use-nuxt-data). Here's how you could implement this: On your "/" page:

<script setup>
const { data } = await useFetch('/api/...', {
  key: 'my-api-data'
})
</script>

<script setup>
const { data } = await useFetch('/api/...', {
  key: 'my-api-data'
})
</script>

On your "/whatever-page" or when returning to "/":

<script setup>
const { data } = useNuxtData('my-api-data')

// If data doesn't exist in cache, fetch it
if (!data.value) {
  const { data: freshData } = await useFetch('/api/...', {
    key: 'my-api-data'
  })
  data.value = freshData.value
}
</script>

<script setup>
const { data } = useNuxtData('my-api-data')

// If data doesn't exist in cache, fetch it
if (!data.value) {
  const { data: freshData } = await useFetch('/api/...', {
    key: 'my-api-data'
  })
  data.value = freshData.value
}
</script>

3. Optimistic Updates: If you need to update the data after a mutation, you can use optimistic updates with useNuxtData. This allows you to update the UI immediately while refreshing the data in the background Docs > Api > Composables > useNuxtData > Optimistic Updates (https://nuxt.com/docs/api/composables/use-nuxt-data#optimistic-updates). 4. Route Rules for Caching: For more advanced caching strategies, you can use Nuxt's route rules to define caching behavior for specific routes. This can help in scenarios where you want to cache data for a certain period Docs > Guide > Concepts > Rendering > Hybrid Rendering (https://nuxt.com/docs/guide/concepts/rendering#hybrid-rendering). 5. Lazy Fetching: If you want to avoid blocking navigation while fetching data, you can use the lazy option with useFetch. This will allow the navigation to complete before the data is fetched Docs > Getting-started > Data fetching > Lazy (https://nuxt.com/docs/getting-started/data-fetching#lazy). Here's an example:

const { status, data: posts } = useLazyFetch('/api/posts', {
  key: 'my-api-data'
})

const { status, data: posts } = useLazyFetch('/api/posts', {
  key: 'my-api-data'
})

By combining these approaches, you can create an efficient caching strategy that minimizes API requests and improves user experience. The exact implementation will depend on your specific requirements, but these tools provide a solid foundation for managing data across page navigations in Nuxt. ---------------------- Note: you can ask me a follow up question by @ mentioning me again :speech_balloon: ----------------------

kapa.ai•3w ago

<@301830740675526657> Kapa.ai is still learning and improving, please let me know how I did by reacting below.

lpmagalOP•3w ago

@kapa.ai alright. In this case, the component does not need to server-render the data as I'm showing the "loading" state of the componente. Is the lazyFetch still required ?

kapa.ai•3w ago

Let me check the knowledge base for you again. One moment! :books: ---------------------- Based on your specific use case where you're showing a loading state and don't need server-side rendering of the data, you can indeed use a different approach. Let's clarify this using the available information: 1. Client-side only fetching: If you don't need the data to be server-rendered and are comfortable with showing a loading state, you can use the server: false option with useFetch. This will ensure that the data is only fetched on the client-side Docs > Getting-started > Data fetching > Client-only fetching (https://nuxt.com/docs/getting-started/data-fetching#client-only-fetching). Here's how you can implement this:

const { status, data: posts } = useFetch('/api/posts', {
  key: 'my-api-data',
  server: false
})

const { status, data: posts } = useFetch('/api/posts', {
  key: 'my-api-data',
  server: false
})

2. Lazy fetching: In this case, useLazyFetch is not strictly required. The main difference between useFetch with server: false and useLazyFetch is that useLazyFetch doesn't block navigation, while useFetch with server: false will still await the data on client-side navigation (but not on initial load) Docs > Getting-started > Data fetching > Client-only fetching (https://nuxt.com/docs/getting-started/data-fetching#client-only-fetching). 3. Handling loading state: With this approach, you'll need to handle the loading state in your component. The status variable from useFetch can help you manage this:

<template>
  <div v-if="status === 'pending'">
    Loading...
  </div>
  <div v-else>
    {{ posts }}
  </div>
</template>

<script setup>
const { status, data: posts } = useFetch('/api/posts', {
  key: 'my-api-data',
  server: false
})
</script>

<template>
  <div v-if="status === 'pending'">
    Loading...
  </div>
  <div v-else>
    {{ posts }}
  </div>
</template>

<script setup>
const { status, data: posts } = useFetch('/api/posts', {
  key: 'my-api-data',
  server: false
})
</script>

4. Caching behavior: Using this method, the data will still be cached based on the key you provide. This means that when navigating back to the page, it will use the cached data if available, potentially avoiding unnecessary API calls Docs > Getting-started > Data fetching > Keys (https://nuxt.com/docs/getting-started/data-fetching#keys). In conclusion, for your specific use case where you're showing a loading state and don't need server-side rendering, using useFetch with server: false is sufficient. You don't necessarily need useLazyFetch unless you want to avoid blocking navigation on subsequent client-side route changes. This approach will still provide caching benefits while allowing you to handle the loading state as needed in your component. ---------------------- Note: you can ask me a follow up question by @ mentioning me again :speech_balloon: ----------------------

kapa.ai•3w ago

<@301830740675526657> Kapa.ai is still learning and improving, please let me know how I did by reacting below.

lpmagalOP•3w ago

@kapa.ai what about cache at server side - nitro, for example ?

kapa.ai•3w ago

Let me check the knowledge base for you again. One moment! :books: ---------------------- Certainly! Let's discuss server-side caching with Nitro in Nuxt. Nitro, which is the server engine used by Nuxt, provides powerful caching capabilities at the server level. 1. Nitro Caching: Nitro offers a built-in caching system that works on top of its storage layer. This allows you to cache responses from your server routes efficiently Guide > Cache (https://nitro.unjs.io/guide/cache). 2. Route Rules for Caching: One of the most straightforward ways to implement server-side caching in Nuxt is by using route rules. These rules allow you to define caching strategies for specific routes. Here's an example:

export default defineNuxtConfig({
  routeRules: {
    '/api/**': { cache: { maxAge: 60 * 60 } }, // Cache API routes for 1 hour
    '/blog/**': { swr: true }, // Use stale-while-revalidate strategy
    '/products/**': { swr: 3600 } // SWR with 1 hour cache
  }
})

export default defineNuxtConfig({
  routeRules: {
    '/api/**': { cache: { maxAge: 60 * 60 } }, // Cache API routes for 1 hour
    '/blog/**': { swr: true }, // Use stale-while-revalidate strategy
    '/products/**': { swr: 3600 } // SWR with 1 hour cache
  }
})

This configuration caches API routes for an hour, uses stale-while-revalidate for blog routes, and caches product routes for an hour with SWR Docs > Guide > Concepts > Rendering > Hybrid Rendering (https://nuxt.com/docs/guide/concepts/rendering#hybrid-rendering). 3. Caching with defineCachedEventHandler: For more fine-grained control, you can use defineCachedEventHandler in your server routes:

export default defineCachedEventHandler((event) => {
  // Your handler logic here
}, {
  maxAge: 60 * 60 // Cache for 1 hour
})

export default defineCachedEventHandler((event) => {
  // Your handler logic here
}, {
  maxAge: 60 * 60 // Cache for 1 hour
})

This allows you to cache specific server handlers with custom options Guide > Cache (https://nitro.unjs.io/guide/cache). 4. Customizing Cache Storage: By default, Nitro uses memory storage for caching in production. However, you can customize this to use different storage solutions. For example, to use Redis:

export default defineNuxtConfig({
  nitro: {
    storage: {
      redis: {
        driver: 'redis',
        /* redis connector options */
        port: 6379,
        host: "127.0.0.1",
        username: "",
        password: "",
        db: 0
      }
    }
  }
})

export default defineNuxtConfig({
  nitro: {
    storage: {
      redis: {
        driver: 'redis',
        /* redis connector options */
        port: 6379,
        host: "127.0.0.1",
        username: "",
        password: "",
        db: 0
      }
    }
  }
})

This configuration sets up Redis as the cache storage Guide > Customize cache storage (https://nitro.unjs.io/guide/cache#customize-cache-storage). 5. Caching in Serverless Environments: For serverless deployments, like Vercel, you might need to use a distributed cache. Vercel KV (based on Redis) can be used for this purpose:

export default defineNuxtConfig({
  nitro: {
    storage: {
      data: { driver: 'vercelKV' }
    }
  }
})

export default defineNuxtConfig({
  nitro: {
    storage: {
      data: { driver: 'vercelKV' }
    }
  }
})

This sets up Vercel KV as the cache storage for your Nuxt application Deploy > Providers > Vercel KV storage (https://nitro.unjs.io/deploy/providers/vercel#vercel-kv-storage). 6. Cache Invalidation: Remember that with server-side caching, you'll need to consider cache invalidation strategies to ensure your data remains fresh when needed. By leveraging these server-side caching capabilities, you can significantly improve the performance of your Nuxt application, reducing the load on your server and improving response times for your users. ---------------------- Note: you can ask me a follow up question by @ mentioning me again :speech_balloon: ----------------------

kapa.ai•3w ago

<@301830740675526657> Kapa.ai is still learning and improving, please let me know how I did by reacting below.

Gaming

Programming

dumb question: cache usage with useFetch