subscribe - GQty

subscribe() is an asynchronous generator for continuous GraphQL data streams.

const notifications = subscribe(
  ({ subscription }) => subscription.newNotification
);
 
for await (const notification of notifications) {
  console.log("Got new notification:", notification);
}
 
// You may unsubscribe at any point
<button onClick={() => notifications.unsubscribe()}>Unsubscribe</button>;

Options

`cachePolicy`

The cache policy to use for queries or mutations, defaults to default. You can read more about cache policy options in Concepts.

`extensions`

A query extention object, carrying extra information to your query fetcher.

subscribe(({ subscription }) => subscription.newNotification, {
  extentions: {
    authToken: "Bearer ...",
  },
});

gqty/index.ts

const queryFetcher = async ({
  query,
  variables,
  operationName,
  extensions,
}) => {
  const repsonse = await fetch("/graphql", {
    method: "POST",
    headers: {
      authorization: extensions?.authToken,
      "content-type": "application/json",
    },
    body: JSON.stringify({
      query,
      variables,
      operationName,
    }),
  });
 
  return await response.json();
};

`retryPolicy`

Failing queries can be automatically retried, this option allows you to customize the retrying behavior, or disabling it altogether.

Retry Policy	Description
`true`	Enables auto retry with the default options.
`false`	Disables auto retry.
`number`	Enables auto retry with the default options and a custom `maxRetries` count.
`{ maxRetries, retryDelay }`	Enables auto retry with custom options.

When you specify retryPolicy as an object, the following properties are available.

`maxRetries`

The maximum number of times to retry a failed query, defaults to 3.

`retryDelay`

Retry Delay	Description
`number`	A fixed number of milliseconds to wait between retries.
`(attempt: number) => number`	A function that returns the number of milliseconds to wait between retries, the default is an exponential backoff function: $min({2^x}, 30) * 1000\text{ms}$ .

`onError()`

Called when an error is received for Query, Mutation or Subscription.

If omitted, the error will be thrown and active subscriptions will be closed.

`onSelect()`

The onSelect callback is called when a selection is made by accessing the properties of query objects.

onSelect?: (selection: Selection, cache?: CacheDataContainer) => void;

`onSubscribe()`

Called when a subscription is established, receives an unsubscribe function as parameter.

onSubscribe?: (unsubscribe: () => void) => void;

`operationName`

GraphQL operation name for this query, useful for debugging and testing.

resolve