blitz: Automatic Cache Invalidation

What do you want and why?

Currently you need to manually call refetch() or mutate() on a useQuery result after doing a mutation.

We should try to come up with a way to automatically invalidate queries so that most users don’t have to think about it all.

I haven’t spent a lot of time thinking about this, but here’s a couple options.

Based on file structure

We could automatically invalidate queries at the same folder level of the mutation.

So with this file structure,

app/products/queries/getProduct.ts
app/products/queries/getProducts.ts
app/products/mutations/createProduct.ts
app/products/mutations/updateProduct.ts
app/products/mutations/deleteProduct.ts

Calling createProduct, updateProduct, or deleteProduct would invalidate the cache for getProduct and getProducts.

But the problem with this is that app/queries/getDisplayProducts.ts would not be invalidated even thought it is also affected. But maybe this is still worth it if it solves the 80% use case.

Via Some Type of Introspection Magic

Maybe it’s possible for us to compute the entire data graph at build time using a combination of the Prisma DMMF and Typescript? If possible, this would be amazing because we could accurately invalidate all queries anywhere in the app.

I think this would only work with Prisma, so we should still have some other fallback method for Blitz apps without Prisma.

On Route Change

Something else that’s a possibility is busting the cache on route change, but that still requires you to think about it.

I’m super keen to hear anyone’s ideas on this!