Sometimes you need to not only query data from a server, but you also want to push data
from the server to the client. GraphQL-core 3 has you also covered here, because it
implements the “Subscribe” algorithm described in the GraphQL spec. To execute a GraphQL
subscription, you must use the
subscribe() method from the
graphql.subscription module. Instead of a single
function returns an asynchronous iterator yielding a stream of those, unless there was
an immediate error. Of course you will then also need to maintain a persistent channel
to the client (often realized via WebSockets) to push these results back.
GraphQL-core 3 provides many more low-level functions that can be used to work with
GraphQL schemas and queries. We encourage you to explore the contents of the various
graphql.utilities, and to look into the source
code and tests of GraphQL-core 3 in order to find all the functionality that is
provided and understand it in detail.