- If data already exists in cache, a query will return that data instead of making a network request.
- Everything that has a data dependency on something in the cache will automatically update when the data is updated, e.g. after a mutation.
- Cache data can be optimistically updated before the request completes, UI that queries this data will automatically update.
- Components will automatically refetch data if they need to, e.g. if an object is partially updated.
The pain points are pretty painful though:
- Really hard to debug unexpected refetches.
- Normalizing the data for the cache comes at a cost, it can be pretty slow for big responses.
- You quickly realise you need to really understand how the client works under the hood to be productive with debugging/complex behaviour.
I see it as a case of "this is the worst API/client, except for all the others". I'm curious to hear how people using non-graphql APIs are managing data in the client in web-apps with complex data needs?
[1] https://www.apollographql.com/docs/react/why-apollo [2] https://relay.dev/