[✨] Nextjs style cache revalidation for server fetched data

[engineersamwell]

Is your feature request related to a problem?

Currently when fetching data in a routeLoader$ i've noticed stale data with back buttoning after changing an item. Let's say I'm fetching products in a routeLoader$ to be displayed on a products page, then I click a product that takes me to product 1 with name 'a' which I change the name to 'b' then I back button to the products page. The list will still show product 1 with 'a' instead of the correct value 'b'. If I forward and back again it will show the change.

• Note this is with default settings and not changing the cacheControl. I can fix this issue if I use cacheControl to disable the cache completely, but imo that's not optimal. I should be able to aggressively cache content while having the manual control to revalidate that content only when I know it's changed.

Describe the solution you'd like

Nextjs solves this issue with cache revalidation in a few ways, see: https://nextjs.org/docs/app/building-your-application/data-fetching/forms-and-mutations#revalidating-data

You can either revalidate a path:

export default async function submit() {
  await submitForm()
  revalidatePath('/')
}

Or revalidate a collection associated with a fetch:

export default async function Page() {
  const res = await fetch('https://...', { next: { tags: ['posts'] } })
  const data = await res.json()
  // ...
}

export default async function submit() {
  await addPost()
  revalidateTag('posts')
}

The revalidateTag is very precise and a solution I would love to see with Qwik.

Describe alternatives you've considered

• One alternative is to disable caching or to use staleWhileRevalidate with a shorter maxAge
• Another would be to use client side fetching, but I don't really consider this an option as it negates much of the benefit of Qwik server side data fetching.

Additional context

No response

[gioboa]

We moved this issue to qwik-evolution repo to create a RFC discussion for this.
Here is our Qwik RFC process thanks.