rsnext/examples/with-relay-modern-server-express/lib/createRelayEnvironment.js
2018-12-10 22:05:53 +01:00

52 lines
1.5 KiB
JavaScript

import { Environment, Network, RecordSource, Store } from 'relay-runtime'
import fetch from 'isomorphic-unfetch'
let relayEnvironment = null
// Define a function that fetches the results of an operation (query/mutation/etc)
// and returns its results as a Promise:
function fetchQuery (
operation,
variables,
cacheConfig,
uploadables
) {
// Because we implement the graphql server, the client must to point to the same host
const relayServer = process.browser ? '' : process.env.RELAY_SERVER
return fetch(`${relayServer}/graphql`, {
method: 'POST',
headers: {
'Accept': 'application/json',
'Content-Type': 'application/json'
}, // Add authentication and other headers here
body: JSON.stringify({
query: operation.text, // GraphQL text from input
variables
})
}).then(response => response.json())
}
export default function initEnvironment ({ records = {} } = {}) {
// Create a network layer from the fetch function
const network = Network.create(fetchQuery)
const store = new Store(new RecordSource(records))
// Make sure to create a new Relay environment for every server-side request so that data
// isn't shared between connections (which would be bad)
if (!process.browser) {
return new Environment({
network,
store
})
}
// reuse Relay environment on client-side
if (!relayEnvironment) {
relayEnvironment = new Environment({
network,
store
})
}
return relayEnvironment
}