<ShowBase>
<ShowBase> is a headless variant of <Show>. It fetches the record from the data provider via dataProvider.getOne(), puts it in a ShowContext, and renders its child. Use it to build a custom show page layout.
Contrary to <Show>, it does not render the page layout, so no title, no actions, and no <Card>.
<ShowBase> relies on the useShowController hook.
Usage
Use <ShowBase> instead of <Show> when you want a completely custom page layout, without the default actions and title.
// in src/posts.jsx
import * as React from "react";
import { ShowBase } from 'react-admin';
const PostShow = () => (
    <ShowBase resource="posts">
        <Grid container>
            <Grid item xs={8}>
                <SimpleShowLayout>
                    ...
                </SimpleShowLayout>
            </Grid>
            <Grid item xs={4}>
                Show instructions...
            </Grid>
        </Grid>
        <div>
            Post related links...
        </div>
    </ShowBase>
);
Components using <ShowBase> can be used as the show prop of a <Resource> component:
// in src/App.jsx
import { Admin, Resource } from 'react-admin';
import { dataProvider } from './dataProvider';
import { PostShow } from './posts';
const App = () => (
    <Admin dataProvider={dataProvider}>
        <Resource name="posts" show={PostShow} />
    </Admin>
);
Tip: See useShowController for a completely headless version of this component.
Props
| Prop | Required | Type | Default | Description | 
|---|---|---|---|---|
| authLoading | Optional | ReactNode | The component to render while checking for authentication and permissions | |
| children | Optional | ReactNode | The components rendering the record fields | |
| render | Optional | (props: ShowControllerResult<RecordType>) => ReactNode | Alternative to children, a function that takes the ShowController context and renders the form | |
| disable Authentication | Optional | boolean | Set to trueto disable the authentication check | |
| error | Optional | ReactNode | The component to render when failing to load the record | |
| id | Optional | string | The record identifier. If not provided, it will be deduced from the URL | |
| loading | Optional | ReactNode | The component to render while loading the record to show | |
| offline | Optional | ReactNode | The component to render when there is no connectivity and the record isn’t in the cache | |
| queryOptions | Optional | object | The options to pass to the useQueryhook | |
| redirectOnError | Optional | 'list'|false|function | 'list' | The page to redirect to when an error occurs | 
| resource | Optional | string | The resource name, e.g. posts | 
authLoading
By default, <ShowBase> renders the children while checking for authentication and permissions. You can display a component during this time via the authLoading prop:
import { ShowBase } from 'react-admin';
export const PostShow = () => (
    <ShowBase authLoading={<p>Checking for permissions...</p>}>
        ...
    </ShowBase>
);
children
<ShowBase> renders its children wrapped by a RecordContext, so you can use any component that depends on such a context to be defined - including all Field components.
For instance, to display several fields in a single line, you can use Material UI’s <Grid> component:
import { ShowBase, TextField, DateField, ReferenceField, WithRecord } from 'react-admin';
import { Grid } from '@mui/material';
import StarIcon from '@mui/icons-material/Star';
const BookShow = () => (
    <ShowBase>
        <Grid container spacing={2} sx={{ margin: 2 }}>
            <Grid item xs={12} sm={6}>
                <TextField label="Title" source="title" />
            </Grid>
            <Grid item xs={12} sm={6}>
                <ReferenceField label="Author" source="author_id" reference="authors">
                    <TextField source="name" />
                </ReferenceField>
            </Grid>
            <Grid item xs={12} sm={6}>
                <DateField label="Publication Date" source="published_at" />
            </Grid>
            <Grid item xs={12} sm={6}>
                <WithRecord label="Rating" render={record => <>
                    {[...Array(record.rating)].map((_, index) => <StarIcon key={index} />)}
                </>} />
            </Grid>
        </Grid>
    </ShowBase>
);
disableAuthentication
By default, the <ShowBase> component will automatically redirect the user to the login page if the user is not authenticated. If you want to disable this behavior and allow anonymous access to a show page, set the disableAuthentication prop to true.
import { ShowBase } from 'react-admin';
const PostShow = () => (
    <ShowBase disableAuthentication>
        ...
    </ShowBase>
);
error
By default, <ShowBase> redirects to the list when an error happens while loading the record to show. You can render an error component via the error prop:
import { ShowBase } from 'react-admin';
export const PostShow = () => (
    <ShowBase error={<p>Something went wrong while loading your post!</p>}>
        ...
    </ShowBase>
);
id
By default, <ShowBase> deduces the identifier of the record to show from the URL path. So under the /posts/123/show path, the id prop will be 123. You may want to force a different identifier. In this case, pass a custom id prop.
import { ShowBase } from 'react-admin';
export const PostShow = () => (
    <ShowBase id="123">
        ...
    </ShowBase>
);
Tip: Pass both a custom id and a custom resource prop to use <ShowBase> independently of the current URL. This even allows you to use more than one <ShowBase> component in the same page.
loading
By default, <ShowBase> renders the children while loading the record to show. You can display a component during this time via the loading prop:
import { ShowBase } from 'react-admin';
export const PostShow = () => (
    <ShowBase loading={<p>Loading the post...</p>}>
        ...
    </ShowBase>
);
offline
By default, <ShowBase> renders nothing when there is no connectivity and the record hasn’t been cached yet. You can provide your own component via the offline prop:
import { ShowBase } from 'react-admin';
export const PostShow = () => (
    <ShowBase offline={<p>No network. Could not load the post.</p>}>
        ...
    </ShowBase>
);
Tip: If the record is in the Tanstack Query cache but you want to warn the user that they may see an outdated version, you can use the <IsOffline> component:
import { ShowBase, IsOffline } from 'react-admin';
export const PostShow = () => (
    <ShowBase offline={<p>No network. Could not load the post.</p>}>
        <IsOffline>
            No network. The post data may be outdated.
        </IsOffline>
        ...
    </ShowBase>
);
queryOptions
<ShowBase> accepts a queryOptions prop to pass options to the react-query client.
This can be useful e.g. to override the default error side effect. By default, when the dataProvider.getOne() call fails at the dataProvider level, react-admin shows an error notification and refreshes the page.
You can override this behavior and pass custom side effects by providing a custom queryOptions prop:
import * as React from 'react';
import { useNotify, useRefresh, useRedirect, ShowBase, SimpleShowLayout } from 'react-admin';
const PostShow = () => {
    const notify = useNotify();
    const refresh = useRefresh();
    const redirect = useRedirect();
    const onError = (error) => {
        notify(`Could not load post: ${error.message}`, { type: 'error' });
        redirect('/posts');
        refresh();
    };
    return (
        <ShowBase queryOptions=>
            <SimpleShowLayout>
                ...
            </SimpleShowLayout>
        </ShowBase>
    );
}
The onError function receives the error from the dataProvider call (dataProvider.getOne()), which is a JavaScript Error object (see the dataProvider documentation for details).
The default onError function is:
(error) => {
    notify('ra.notification.item_doesnt_exist', { type: 'error' });
    redirect('list', resource);
    refresh();
}
redirectOnError
By default, <ShowBase> redirects to the list when an error happens while loading the record to show. You can change the default redirection by setting the redirectOnError prop:
- 'list': redirect to the List view (the default)
- false: do not redirect
- A function (resource, id) => stringto redirect to different targets depending on the record
import { ShowBase } from 'react-admin';
export const PostShow = () => (
    <ShowBase redirectOnError={false}>
        ...
    </ShowBase>
);
render
Alternatively, you can pass a render function prop instead of children. This function will receive the ShowContext as argument.
import { ShowBase, TextField, DateField, ReferenceField, WithRecord } from 'react-admin';
const BookShow = () => (
    <ShowBase render={({ isPending, error, record }) => {
        if (isPending) {
            return <p>Loading...</p>;
        }
        if (error) {
            return (
                <p className="error">
                    {error.message}
                </p>
            );
        }
        return <p>{record.title}</p>;
    }}/>
);
resource
By default, <ShowBase> operates on the current ResourceContext (defined at the routing level), so under the /posts/1/show path, the resource prop will be posts. You may want to force a different resource. In this case, pass a custom resource prop, and it will override the ResourceContext value.
import { ShowBase } from 'react-admin';
export const UsersShow = () => (
    <ShowBase resource="users">
        ...
    </ShowBase>
);
Tip: Pass both a custom id and a custom resource prop to use <ShowBase> independently of the current URL. This even allows you to use more than one <ShowBase> component in the same page.
Security
The <ShowBase> component requires authentication and will redirect anonymous users to the login page. If you want to allow anonymous access, use the disableAuthentication prop.
If your authProvider implements Access Control, <ShowBase>  will only render if the user has the “show” access to the related resource.
For instance, for the <PostShow>page below:
import { ShowBase, SimpleShowLayout, TextField } from 'react-admin';
// Resource name is "posts"
const PostShow = () => (
    <ShowBase>
        <SimpleShowLayout>
            <TextField source="title" />
            <TextField source="author" />
            <TextField source="published_at" />
        </SimpleShowLayout>
    </ShowBase>
);
<ShowBase> will call authProvider.canAccess() using the following parameters:
{ action: "show", resource: "posts" }
Users without access will be redirected to the Access Denied page.
Note: Access control is disabled when you use the disableAuthentication prop.
