Loading...
}\n * {JSON.stringify(accumulatedData, undefined, 2)}\n * \n * );\n * }\n * ```\n *\n * Instead of using `useEffect` here, we can re-write this component to use the `onData` callback function accepted in `useSubscription`'s `options` object:\n *\n * ```jsx\n * export function Subscriptions() {\n * const [accumulatedData, setAccumulatedData] = useState([]);\n * const { data, error, loading } = useSubscription(\n * query,\n * {\n * onData({ data }) {\n * setAccumulatedData((prev) => [...prev, data])\n * }\n * }\n * );\n *\n * return (\n * <>\n * {loading &&Loading...
}\n * {JSON.stringify(accumulatedData, undefined, 2)}\n * \n * );\n * }\n * ```\n *\n * > ⚠️ **Note:** The `useSubscription` option `onData` is available in Apollo Client >= 3.7. In previous versions, the equivalent option is named `onSubscriptionData`.\n *\n * Now, the first message will be added to the `accumulatedData` array since `onData` is called _before_ the component re-renders. React 18 automatic batching is still in effect and results in a single re-render, but with `onData` we can guarantee each message received after the component mounts is added to `accumulatedData`.\n *\n * @since 3.0.0\n * @param subscription - A GraphQL subscription document parsed into an AST by `gql`.\n * @param options - Options to control how the subscription is executed.\n * @returns Query result object\n */\nexport function useSubscription<\n TData = any,\n TVariables extends OperationVariables = OperationVariables,\n>(\n subscription: DocumentNode | TypedDocumentNode