MutationCache

The MutationCache is the storage for mutations.

Normally, you will not interact with the MutationCache directly and instead use the QueryClient.

1 import { MutationCache } from 'react-query'
2 
3 const mutationCache = new MutationCache()

Its available methods are:

• getAll
• subscribe
• clear

mutationCache.getAll

getAll returns all mutations within the cache.

Note: This is not typically needed for most applications, but can come in handy when needing more information about a mutation in rare scenarios

 const mutations = mutationCache.getAll()

Returns

• Mutation[]
  • Mutation instances from the cache

mutationCache.subscribe

The subscribe method can be used to subscribe to the mutation cache as a whole and be informed of safe/known updates to the cache like mutation states changing or mutations being updated, added or removed.

1 const callback = mutation => {
2   console.log(mutation)
3 }
4 
5 const unsubscribe = mutationCache.subscribe(callback)

Options

• callback: (mutation?: Mutation) => void
  • This function will be called with the mutation cache any time it is updated.

Returns

• unsubscribe: Function => void
  • This function will unsubscribe the callback from the mutation cache.

mutationCache.clear

The clear method can be used to clear the cache entirely and start fresh.

 mutationCache.clear()