useMany Hook | Options, Patterns & Edge Cases in Refine v5

import BasicUsageLivePreview from "./_basic-usage-live-preview.md";

useMany is an extended version of TanStack Query's useQuery that supports all of its features and adds some more.

• It uses the getMany method as the query function from the dataProvider which is passed to <Refine>.

• It uses a query key to cache the data. The query key is generated from the provided properties. You can see the query key by using the TanStack Query devtools.

It is useful when you want to fetch multiple records from the API. It will return the data and some functions to control the query.

If your data provider does not have a getMany method, useMany will use the getOne method instead. This is not recommended, as it will make requests one by one for each id. It is better to implement the getMany method in the data provider.

Usage

The useMany hook expects a resource and ids property, which will be passed to the getMany method from the dataProvider as a parameter.

When these properties are changed, the useMany hook will trigger a new request.

Realtime Updates

This feature is only available if you use a Live Provider.

When the useMany hook is mounted, it will call the subscribe method from the liveProvider with some parameters such as channel, resource etc. It is useful when you want to subscribe to live updates.

Properties

resource <PropTag required />

This parameter will be passed to the getMany method from the dataProvider as a parameter. t is usually used as an API endpoint path but it all depends on how you handle the resource in the getMany method.

useMany({
  resource: "categories",
});

For more information, refer to the creating a data provider tutorial &#8594

If you have multiple resources with the same name, you can pass the identifier instead of the name of the resource. It will only be used as the main matching key for the resource, data provider methods will still work with the name of the resource defined in the <Refine/> component.

For more information, refer to the identifier of the <Refine/> component documentation &#8594

ids <PropTag required />

This prop will be passed to the getMany method from the dataProvider as a parameter. It is used to determine which records to fetch.

useMany({
  ids: [1, 2, 3],
});

dataProviderName

This prop allows you to specify which dataProvider if you have more than one. Just pass it like in the example:

useMany({
  dataProviderName: "second-data-provider",
});

queryOptions

queryOptions is used to pass additional options to the useQuery hook. It is useful when you want to pass additional options to the useQuery hook.

useMany({
  queryOptions: {
    retry: 3,
    enabled: false,
  },
});

For more information, refer to the useQuery documentation&#8594

meta

meta is a special property that can be used to pass additional information to data provider methods for the following purposes:

• Customizing the data provider methods for specific use cases.
• Generating GraphQL queries using plain JavaScript Objects (JSON).

In the following example, we pass the headers property in the meta object to the create method. With similar logic, you can pass any properties to specifically handle the data provider methods.

import { stringify } from "query-string";

useMany({
  // highlight-start
  meta: {
    headers: { "x-meta-data": "true" },
  },
  // highlight-end
});

const myDataProvider = {
  //...
  getMany: async ({
    resource,
    ids,
    // highlight-next-line
    meta,
  }) => {
    // highlight-next-line
    const headers = meta?.headers ?? {};
    const url = `${apiUrl}/${resource}?${stringify({ id: ids })}`;

    //...
    //...

    // highlight-next-line
    const { data } = await httpClient.get(`${url}`, { headers });

    return {
      data,
    };
  },
  //...
};

For more information, refer to the meta section of the General Concepts documentation&#8594

successNotification

NotificationProvider is required for this prop to work.

After data is fetched successfully, useMany can call open function from NotificationProvider to show a success notification. With this prop, you can customize the success notification.

useMany({
  successNotification: (data, ids, resource) => {
    return {
      message: `${data.title} Successfully fetched.`,
      description: "Success with no errors",
      type: "success",
    };
  },
});

errorNotification

NotificationProvider is required for this prop to work.

After data fetching is failed, useMany will call the open function from NotificationProvider to show an error notification. With this prop, you can customize the error notification.

useMany({
  errorNotification: (data, ids, resource) => {
    return {
      message: `Something went wrong when getting ${data.id}`,
      description: "Error",
      type: "error",
    };
  },
});

liveMode

LiveProvider is required for this prop to work.

Determines whether to update data automatically ("auto") or not ("manual") if a related live event is received. It can be used to update and show data in Realtime throughout your app.

useMany({
  liveMode: "auto",
});

onLiveEvent

LiveProvider is required for this prop to work.

The callback function is executed when new events from a subscription have arrived.

useMany({
  onLiveEvent: (event) => {
    console.log(event);
  },
});

liveParams

LiveProvider is required for this prop to work.

Params to pass to liveProvider's subscribe method.

overtimeOptions

If you want loading overtime for the request, you can pass the overtimeOptions prop to the this hook. It is useful when you want to show a loading indicator when the request takes too long. interval is the time interval in milliseconds. onInterval is the function that will be called on each interval.

Return overtime object from this hook. elapsedTime is the elapsed time in milliseconds. It becomes undefined when the request is completed.

const { overtime } = useMany({
  //...
  overtimeOptions: {
    interval: 1000,
    onInterval(elapsedInterval) {
      console.log(elapsedInterval);
    },
  },
});

console.log(overtime.elapsedTime); // undefined, 1000, 2000, 3000 4000, ...

// You can use it like this:
{
  elapsedTime >= 4000 && <div>this takes a bit longer than expected</div>;
}

Return Values

Returns an object with TanStack Query's useQuery return values.

For more information, refer to the useQuery documentation &#8594

Additional Values

overtime

overtime object is returned from this hook. elapsedTime is the elapsed time in milliseconds. It becomes undefined when the request is completed.

const { overtime } = useMany();

console.log(overtime.elapsedTime); // undefined, 1000, 2000, 3000 4000, ...

API Reference

Properties

<PropsTable module="@refinedev/core/useMany" successNotification-default='`false`' errorNotification-default='"Error (status code: `statusCode`)"' />

Type Parameters

Return values