prime#




Functions#

prime

Manually add a key-value pair to a DataLoader cache.

prime()#

rootski.gql.prime.prime(loader: strawberry.dataloader.DataLoader[rootski.gql.prime.TKey, rootski.gql.prime.TValue], key: rootski.gql.prime.TKey, value: rootski.gql.prime.TValue) → None[source]#

Manually add a key-value pair to a DataLoader cache.

This is useful for reducing hits to a backend data store that is hit by the DataLoader in question. For example, if we want to query a database for a “page” of records, we will not know the IDs of those records in advance. Since DataLoaders are (usually) used to fetch records by ID, we cannot use DataLoaders to fetch pages.

Therefore, the query for these objects must be done outside of the DataLoader. However, once we’ve queried a page of records (not using the DataLoader), we will want to make the DataLoader aware of our fetched objects so that we will not needlessly fetch the same objects again. This function can be used to accomplish that.

Note

This function is an official part of the GraphQL JavaScript reference implementation. The subset of the GraphQL Dataloader API that has to do with this is called the “Prime API”. Unfortunately, it has not been included in strawberry-graphql as of Nov 1, 2021.

You can think of this function as “priming” a DataLoader’s cache with a value we acquired by some means other than calling DataLoader.load().

Parameters

  • loader – The DataLoader whose cache will have the key-value pair added to

  • key – The same type of key used in a call to DataLoader.load_fn(key)

  • value – The value that DataLoader.load_fn(key) should return. This should not be an Awaitable or a Future, but the actual value that would be the result of the Future after being awaited.