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import { createFetchMultipartSubscription } from '@apollo/client/utilities/subscriptions/relay';
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import { Environment, Network, RecordSource, Store } from 'relay-runtime';
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const fetchMultipartSubs = createFetchMultipartSubscription('https://api.example.com');
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const network = Network.create(fetchQuery, fetchMultipartSubs);
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export const RelayEnvironment = new Environment({
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  network,
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  store: new Store(new RecordSource()),
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});

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import { createFetchMultipartSubscription } from '@apollo/client/utilities/subscriptions/urql';
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import { Client, fetchExchange, subscriptionExchange } from '@urql/core';
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const url = 'https://api.example.com';
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const multipartSubscriptionForwarder = createFetchMultipartSubscription(url);
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const client = new Client({
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  url,
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  exchanges: [
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    fetchExchange,
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    subscriptionExchange({
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      forwardSubscription: multipartSubscriptionForwarder,
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    }),
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  ],
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});

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const COMMENTS_SUBSCRIPTION: TypedDocumentNode<
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  OnCommentAddedSubscription,
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  OnCommentAddedSubscriptionVariables
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> = gql`
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  subscription OnCommentAdded($postID: ID!) {
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    commentAdded(postID: $postID) {
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      id
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      content
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    }
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  }
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`;

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import { GraphQLWsLink } from '@apollo/client/link/subscriptions';
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import { createClient } from 'graphql-ws';
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const wsLink = new GraphQLWsLink(
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  createClient({
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    url: 'ws://127.0.0.1:4000/subscriptions',
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  }),
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);

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import { split, HttpLink } from '@apollo/client';
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import { getMainDefinition } from '@apollo/client/utilities';
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import { GraphQLWsLink } from '@apollo/client/link/subscriptions';
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import { createClient } from 'graphql-ws';
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const httpLink = new HttpLink({
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  uri: 'https://127.0.0.1:4000/graphql',
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});
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const wsLink = new GraphQLWsLink(
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  createClient({
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    url: 'ws://127.0.0.1:4000/subscriptions',
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  }),
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);
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// The split function takes three parameters:
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//
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// * A function that's called for each operation to execute
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// * The Link to use for an operation if the function returns a "truthy" value
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// * The Link to use for an operation if the function returns a "falsy" value
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const splitLink = split(
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  ({ query }) => {
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    const definition = getMainDefinition(query);
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    return definition.kind === 'OperationDefinition' && definition.operation === 'subscription';
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  },
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  wsLink,
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  httpLink,
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);

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import { ApolloClient, InMemoryCache } from '@apollo/client';
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// ...code from the above example goes here...
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const client = new ApolloClient({
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  link: splitLink,
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  cache: new InMemoryCache()
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});

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import { GraphQLWsLink } from '@apollo/client/link/subscriptions';
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import { createClient } from 'graphql-ws';
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const wsLink = new GraphQLWsLink(createClient({
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  url: 'ws://127.0.0.1:4000/subscriptions',
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  connectionParams: {
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    authToken: user.authToken,
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  },
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}));

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const COMMENTS_SUBSCRIPTION: TypedDocumentNode<
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  OnCommentAddedSubscription,
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  OnCommentAddedSubscriptionVariables
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> = gql`
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  subscription OnCommentAdded($postID: ID!) {
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    commentAdded(postID: $postID) {
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      id
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      content
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    }
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  }
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`;
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function LatestComment({ postID }: LatestCommentProps) {
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  const { data, loading } = useSubscription(
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    COMMENTS_SUBSCRIPTION,
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    { variables: { postID } }
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  );
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  return <h4>New comment: {!loading && data.commentAdded.content}</h4>;
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}

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const COMMENTS_QUERY: TypedDocumentNode<
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  CommentsForPostQuery,
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  CommentsForPostQueryVariables
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> = gql`
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  query CommentsForPost($postID: ID!) {
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    post(postID: $postID) {
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      comments {
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        id
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        content
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      }
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    }
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  }
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`;
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function CommentsPageWithData({ params }: CommentsPageWithDataProps) {
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  const result = useQuery(
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    COMMENTS_QUERY,
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    { variables: { postID: params.postID } }
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  );
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  return <CommentsPage {...result} />;
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}

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const COMMENTS_SUBSCRIPTION: TypedDocumentNode<
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  OnCommentAddedSubscription,
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  OnCommentAddedSubscriptionVariables
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> = gql`
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  subscription OnCommentAdded($postID: ID!) {
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    commentAdded(postID: $postID) {
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      id
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      content
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    }
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  }
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`;

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function CommentsPageWithData({ params }: CommentsPageWithDataProps) {
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  const { subscribeToMore, ...result } = useQuery(
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    COMMENTS_QUERY,
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    { variables: { postID: params.postID } }
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  );
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  return (
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    <CommentsPage
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      {...result}
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      subscribeToNewComments={() =>
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        subscribeToMore({
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          document: COMMENTS_SUBSCRIPTION,
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          variables: { postID: params.postID },
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          updateQuery: (prev, { subscriptionData }) => {
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            if (!subscriptionData.data) return prev;
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            const newFeedItem = subscriptionData.data.commentAdded;
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            return Object.assign({}, prev, {
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              post: {
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                comments: [newFeedItem, ...prev.post.comments]
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              }
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            });
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          }
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        })
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      }
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    />
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  );
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}

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export function CommentsPage({ subscribeToNewComments }: CommentsPageProps) {
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  useEffect(() => subscribeToNewComments(), []);
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  return <>...</>
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}