@n1ru4l/in-memory-live-query-store
A GraphQL live query store that tracks, invalidates and re-executes registered operations. Drop in replacement for graphql-js
execute
. Add live query capabilities to your existing GraphQL schema.
Check out the todo example server for a sample integration.
Install Instructions
yarn add -E @n1ru4l/in-memory-live-query-store
API
InMemoryLiveQueryStore
A InMemoryLiveQueryStore
instance tracks, invalidates and re-executes registered live query operations.
The store will keep track of all root query field coordinates (e.g. Query.todos
) and global resource identifiers (e.g. Todo:1
). The store can than be notified to re-execute live query operations that select a given root query field or resource identifier by calling the invalidate
method with the corresponding values.
A resource identifier is composed out of the typename and the actual resolved id value separated by a colon, but can be customized. For ensuring that the store keeps track of all your query resources you should always select the id
field on your object types. The store will only keep track of fields with the name id
and the type ID!
(GraphQLNonNull(GraphQLID)
).
import { InMemoryLiveQueryStore } from "@n1ru4l/in-memory-live-query-store";
import { parse } from "graphql";
import { schema } from "./schema";
const inMemoryLiveQueryStore = new InMemoryLiveQueryStore();
const rootValue = {
todos: [
{
id: "1",
content: "Foo",
isComplete: false,
},
],
};
inMemoryLiveQueryStore
.execute({
schema,
operationDocument: parse( `
query todosQuery @live {
todos {
id
content
isComplete
}
}
`),
rootValue: rootValue,
contextValue: {},
variableValues: null,
operationName: "todosQuery",
})
.then(async (result) => {
if (isAsyncIterable(result)) {
for (const value of result) {
console.log(value);
}
}
});
rootValue.todos[0].isComplete = true;
inMemoryLiveQueryStore.invalidate(`Todo:1`);
rootValue.todos.push({ id: "2", content: "Baz", isComplete: false });
inMemoryLiveQueryStore.invalidate(`Query.todos`);
The InMemoryLiveQueryStore.execute
function is a drop-in replacement for the default execute
function exported from graphql-js
.
Pass it to your favorite graphql transport that supports returning AsyncIterator
from execute
and thus delivering incremental query execution results.
List of known and tested compatible transports/servers:
Recipes
Using with Redis
You can use Redis to synchronize invalidations across multiple instances.
import Redis from 'ioredis'
import { InMemoryLiveQueryStore } from '@n1ru4l/in-memory-live-query-store'
import {
execute as defaultExecute,
ExecutionArgs,
ExecutionResult
} from 'graphql'
import { LiveExecutionResult } from '@n1ru4l/graphql-live-query'
declare type MaybePromise<T> = T | Promise<T>
declare type ExecutionParameter =
| Parameters<typeof defaultExecute>
| [ExecutionArgs]
export interface LiveQueryStore {
invalidate: (identifiers: Array<string> | string) => Promise<void>
execute: (
...args: ExecutionParameter
) => MaybePromise<
| AsyncIterableIterator<ExecutionResult | LiveExecutionResult>
| ExecutionResult
>
}
const CHANNEL = 'LIVE_QUERY_INVALIDATIONS'
export class RedisLiveQueryStore {
pub: Redis.Redis
sub: Redis.Redis
liveQueryStore: InMemoryLiveQueryStore
constructor(redisUrl: string) {
this.pub = new Redis(redisUrl)
this.sub = new Redis(redisUrl)
this.liveQueryStore = new InMemoryLiveQueryStore()
this.sub.subscribe(CHANNEL, err => {
if (err) throw err
})
this.sub.on('message', (channel, resourceIdentifier) => {
if (channel === CHANNEL && resourceIdentifier)
this.liveQueryStore.invalidate(resourceIdentifier)
})
}
async invalidate(identifiers: Array<string> | string) {
if (typeof identifiers === 'string') {
identifiers = [identifiers]
}
for (const identifier of identifiers) {
this.pub.publish(CHANNEL, identifier)
}
}
execute(...args: ExecutionParameter) {
return this.liveQueryStore.execute(...args)
}
}