Graphql subscription? about apollo-multi-endpoint-link HOT 3 OPEN

import { ApolloLink, NextLink, Operation } from '@apollo/client/link/core'
import { GraphQLWsLink } from '@apollo/client/link/subscriptions'
import { getMainDefinition, hasDirectives } from '@apollo/client/utilities'
import { createClient } from 'graphql-ws'

import { createHttpLink } from './httpLink'

export class GatewayLink extends ApolloLink {
  wsLink: ApolloLink
  httpLink: ApolloLink
  constructor(env: Envs, clientName: string) {
    super()
    this.wsLink = new GraphQLWsLink(
      createClient({
        url: YOUR URL HERE,
        lazy: true,
      })
    )
    this.httpLink = createHttpLink({
      uri:  YOUR URI HERE,
      headers: {
        'X-Request-From': clientName,
      },
    })
  }

  public request(operation: Operation, forward?: NextLink) {
    if (hasDirectives(['rest'], operation.query)) {
      return forward?.(operation) ?? null
    }
    const definition = getMainDefinition(operation.query)
    if (
      definition.kind === 'OperationDefinition' &&
      definition.operation === 'subscription'
    ) {
      return this.wsLink.request(operation, forward)
    }
    return this.httpLink.request(operation, forward)
  }
}