GetStaticProps with ISR doesn't working as expected | Next.js | Page 1

azure ruinBOT Nov 22, 2023, 3:00 PM

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Hi @drifting belfry. I'm kapa.ai, your friendly support bot. I will try to answer your question by searching through the knowledge base. :wave:

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Based on the information provided in the extracts, it seems like you're using the getStaticProps function correctly with the revalidate option. This should regenerate the page every 60 seconds. However, if the data is not updating as expected, there could be a few reasons for this.

Error in Data Fetching: If there's an error in your data fetching methods (bannerService.getBanners() or menuService.getMenuSeeAlso()), Next.js will not invalidate the currently shown page and will retry getStaticProps on the next request. Make sure these methods are working correctly and handling errors appropriately. If there's a server error, you might want to throw an error instead of returning so that the cache is not updated until the next successful request. Source (https://nextjs.org/docs/pages/building-your-application/data-fetching/incremental-static-regeneration)
On-Demand Revalidation: Starting with v12.2.0, Next.js supports On-Demand Incremental Static Regeneration to manually purge the Next.js cache for a specific page. This could be useful if the content from your CMS is updated. Inside getStaticProps, you do not need to specify revalidate to use on-demand revalidation. If revalidate is omitted, Next.js will use the default value of false (no revalidation) and only revalidate the page on-demand when revalidate() is called. Source (https://nextjs.org/docs/pages/building-your-application/data-fetching/incremental-static-regeneration)

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Testing in Development: If you're testing this in a local development environment with next dev, getStaticProps is invoked on every request. To verify your on-demand ISR configuration is correct, you will need to create a production build and start the production server. Source (https://nextjs.org/docs/pages/building-your-application/data-fetching/incremental-static-regeneration)

If none of these solutions work, you might want to check the official Next.js documentation or forums for more specific advice related to your issue.

Note: you can ask me a follow up question by @ mentioning me again :speech_balloon:

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@drifting belfry kapa.ai is still learning and improving, please let us know how it did by reacting below

drifting belfry Nov 22, 2023, 3:04 PM

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@azure ruin how can I implement the revalidation on demand in this case?

azure ruinBOT Nov 22, 2023, 3:04 PM

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Let me check the knowledge base for you. One moment! :books:

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To implement on-demand revalidation in your case, you need to create an API route that triggers revalidation when it receives a request with a specific secret token. Here's how you can do it:

Create a Secret Token: This token will be used to prevent unauthorized access to the revalidation API Route. You can add this secret as an Environment Variable to your application. Source (https://nextjs.org/docs/pages/building-your-application/data-fetching/incremental-static-regeneration)
Create the Revalidation API Route: This route will check for the secret token and trigger revalidation if the token is valid. Here's an example of how you can create this route:

// pages/api/revalidate.js
export default async function handler(req, res) {
  // Check for secret to confirm this is a valid request
  if (req.query.secret !== process.env.MY_SECRET_TOKEN) {
    return res.status(401).json({ message: 'Invalid token' })
  }
  
  try {
    // this should be the actual path not a rewritten path
    // e.g. for "/blog/[slug]" this should be "/blog/post-1"
    await res.revalidate('/path-to-revalidate')
    return res.json({ revalidated: true })
  } catch (err) {
    // If there was an error, Next.js will continue
    // to show the last successfully generated page
    return res.status(500).send('Error revalidating')
  }
}

Source (https://nextjs.org/docs/pages/building-your-application/data-fetching/incremental-static-regeneration)

Trigger Revalidation: You can now trigger revalidation by accessing the route with the following URL structure:

<https://<your-site.com>/api/revalidate?secret=<token>>

Replace <your-site.com> with your actual site URL and <token> with your secret token. Source (https://nextjs.org/docs/pages/building-your-application/data-fetching/incremental-static-regeneration)

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Remember, the path you pass to `res.revalidate()` should be the actual path of the page you want to revalidate, not a rewritten path. For example, if you have `pages/blog/slug].js` and a rewrite from `/post-1` -> `/blog/post-1`, you would need to call `res.revalidate('/blog/post-1')`. [Source (https://nextjs.org/docs/pages/building-your-application/rendering/incremental-static-regeneration)

Note: you can ask me a follow up question by @ mentioning me again :speech_balloon:

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@drifting belfry kapa.ai is still learning and improving, please let us know how it did by reacting below

drifting belfry Nov 22, 2023, 3:06 PM

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@azure ruin could it be a cache problem?

azure ruinBOT Nov 22, 2023, 3:06 PM

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Let me check the knowledge base for you. One moment! :books:

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Yes, it could be a cache issue. Next.js automatically caches the returned values of fetch in the Data Cache on the server. This means that the data can be fetched at build time or request time, cached, and reused on each data request. If the cache is not being invalidated or updated correctly, it could cause the data to not update as expected.

In some circumstances, you may need to delete all cached data and force revalidation. You can do this by purging the Data Cache. Here are the steps to do it:

Under your project, go to the Settings tab.
In the Data Cache section, select Purge Everything.
On the dialog, confirm that you wish to delete and click the Continue & Purge Everything button.

Purging your Data Cache will create a temporary increase in request times for users as new data needs to be refetched. Source (https://vercel.com/docs/infrastructure/data-cache/manage-data-cache)

Also, if you're using fetch requests, they are not cached if:

The cache: 'no-store' is added to fetch requests.
The revalidate: 0 option is added to individual fetch requests.
The fetch request is inside a Router Handler that uses the POST method.
The fetch request comes after the usage of headers or cookies.
The const dynamic = 'force-dynamic' route segment option is used.
The fetchCache route segment option is configured to skip cache by default.
The fetch request uses Authorization or Cookie headers and there's an uncached request above it in the component tree.

To opt out of caching for individual fetch requests, you can set the cache option in fetch to 'no-store'. This will fetch data dynamically, on every request. Source (https://nextjs.org/docs/app/building-your-application/data-fetching/fetching-caching-and-revalidating)

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If none of these solutions work, you might want to check the official Next.js documentation or forums for more specific advice related to your issue.

Note: you can ask me a follow up question by @ mentioning me again :speech_balloon:

#

@drifting belfry kapa.ai is still learning and improving, please let us know how it did by reacting below

drifting belfry Nov 22, 2023, 3:11 PM

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can I implment it on my frontend in my getstaticprops?

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@azure ruin can I implment it on my frontend in my getstaticprops?

azure ruinBOT Nov 22, 2023, 3:12 PM

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Let me check the knowledge base for you. One moment! :books:

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No, you cannot directly implement on-demand revalidation within getStaticProps. The getStaticProps function is used to fetch data at build time and return it as props to your page. It runs only on the server-side and it cannot trigger a revalidation itself.

However, you can use getStaticProps in combination with an API route to achieve on-demand revalidation. The API route can be called from anywhere (like a CMS webhook, a button click in your frontend, etc.) to trigger the revalidation.

Here's an example of how you can create an API route for on-demand revalidation:

// pages/api/revalidate.js
export default async function handler(req, res) {
  // Check for secret to confirm this is a valid request
  if (req.query.secret !== process.env.MY_SECRET_TOKEN) {
    return res.status(401).json({ message: 'Invalid token' })
  }
  
  try {
    // this should be the actual path not a rewritten path
    // e.g. for "/blog/[slug]" this should be "/blog/post-1"
    await res.revalidate('/path-to-revalidate')
    return res.json({ revalidated: true })
  } catch (err) {
    // If there was an error, Next.js will continue
    // to show the last successfully generated page
    return res.status(500).send('Error revalidating')
  }
}

Source (https://nextjs.org/docs/pages/building-your-application/data-fetching/incremental-static-regeneration)

Then, you can trigger revalidation by making a request to this API route from your frontend or CMS webhook:

fetch('/api/revalidate?secret=<your-secret-token>')

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Remember to replace `<your-secret-token>` with your actual secret token. Source (https://nextjs.org/docs/pages/building-your-application/data-fetching/incremental-static-regeneration)

#GetStaticProps with ISR doesn't working as expected

If none of these solutions work, you might want to check the official Next.js documentation or forums for more specific advice related to your issue.

Note: you can ask me a follow up question by @ mentioning me again :speech_balloon:

Note: you can ask me a follow up question by @ mentioning me again :speech_balloon:

If none of these solutions work, you might want to check the official Next.js documentation or forums for more specific advice related to your issue.

Note: you can ask me a follow up question by @ mentioning me again :speech_balloon:

Remember to replace <your-secret-token> with your actual secret token. Source (https://nextjs.org/docs/pages/building-your-application/data-fetching/incremental-static-regeneration)

Note: you can ask me a follow up question by @ mentioning me again :speech_balloon:

Remember to replace `<your-secret-token>` with your actual secret token. Source (https://nextjs.org/docs/pages/building-your-application/data-fetching/incremental-static-regeneration)