revalidateTag doesn't seem to be working

lzyaclast year

14

import type { CollectionAfterChangeHook } from 'payload'

import { revalidateTag } from 'next/cache'

import type { CaseStudy } from '@/payload-types'

export const revalidateTagged: CollectionAfterChangeHook<CaseStudy> = ({
  doc,
  previousDoc,
  req: { payload },
}) => {
  if (doc._status === 'published') {
    const tag = 'case-studies'
    payload.logger.info(`Revalidating tag: ${tag}`)
    revalidateTag(tag)
  }

  return doc
}

• 

  rilromlast year

  Are you using middleware for auth at all? I ran into a similar issue today where middleware was doing a redirect, even though the revalidation function was saying it succeeded.

• 

  lzyaclast year

  no middleware

  
  
  

  i made a simple reproduction using the blank template

  
  
  

  can someone explain where i've made the goof up

  
  
  

  the code of interest is mainly going to be

  src/payload.config.ts

  ,

  src/app/(frontend)/books

  and

  src/collections/Books
  
  

  when I add a book

  https://media.discordapp.net/attachments/1280125746400067584/1280147085328646164/image.png?ex=66d70561&is=66d5b3e1&hm=ed90a4d7522811b2da400d24f5e691f9e0a3774a9d3bcd63d6f8513fd7e73bc5&=&format=webp&quality=lossless&width=2380&height=816
  
  

  i don't see any issues since clearly

  revalidateTag

  has been called

  
  
  

  and

  books

  is part of the tag list in the

  unstable_cache

  wrapped fetch to the Books collection

• 

  rilromlast year

  Could you try something in this format:

  
  
  

  const getCachedUser = unstable_cache(

  
  

  async () => getUser(),

  
  

  ['my-app-user'],

  
  

  { tags: ['user'] }

  
  

  );

• 

  lzyaclast year

  const getBooks = async () => {
    const payload = await getPayloadHMR({ config })
      const books = await payload
        .find({ collection: 'books', pagination: false })
        .then(({ docs }) => docs)
  
      return books
  }
  
  const cachedGetBooks = unstable_cache(
    async () => getBooks(),
    ['books'],
    { tags: ['books'] }
  )

  
  
  

  so like this?

• 

  rilromlast year

  Yep

• 

  lzyaclast year

  let me try that

  
  
  

  bruh why did that work 😭

  
  
  

  like actually

  
  
  

  why does that work

• 

  rilromlast year

  So the tags object is what’s actually used for revalidation, the second parameter you were trying to use is actually for creating separate caches if needed (e.g. per user id)

• 

  lzyaclast year

  what do you mean by separate caches here

• 

  rilromlast year

  Take a look at this example

  https://nextjs.org/docs/app/api-reference/functions/unstable_cache#example
• 

  lzyaclast year

  ohh so it maintains a cached value per id?

• 

  rilromlast year

  It can do yeah

• 

  lzyaclast year

  but what would the purpose of that be?

  
  
  

  im a little new to cache revalidation please bear with me 😅

  
  
  

  because if we revalidate the tag "books"

  
  
  

  then wouldn't all the cached values get refreshed with new values from the data source (e.g payload)

• 

  rilromlast year

  I think an example would be if a user logs out and logs in as someone else in the same session. The user id would change which would invalidate the cache.

• 

  lzyaclast year

  the cache containing the value of the signed in user?

  
  
  

  are there multiple caches in this scenario you've just described

  
  
  

  or is that the only cache

  
  
  

  I've updated my repo to be a simple example of cache revalidation in payload cms :)