useListContext
Whenever react-admin displays a List, it creates a ListContext
to store the list data, as well as filters, pagination, sort state, and callbacks to update them.
The ListContext
is available to descendants of:
<List>
,<ListGuesser>
,<ListBase>
,<ReferenceArrayField>
,<ReferenceManyField>
All descendant components can therefore access the list context, using the useListContext
hook. As a matter of fact, react-admin’s <Datagrid>
, <FilterForm>
, and <Pagination>
components all use the useListContext
hook.
Usage
Call useListContext
in a component, then use this component as a descendant of a List
component.
// in src/posts/Aside.js
import { Typography } from '@mui/material';
import { useListContext } from 'react-admin';
export const Aside = () => {
const { data, isLoading } = useListContext();
if (isLoading) return null;
return (
<div>
<Typography variant="h6">Posts stats</Typography>
<Typography variant="body2">
Total views: {data.reduce((sum, post) => sum + post.views, 0)}
</Typography>
</div>
);
};
// in src/posts/PostList.js
import { List, Datagrid, TextField } from 'react-admin';
import Aside from './Aside';
export const PostList = () => (
<List aside={<Aside />}>
<Datagrid>
<TextField source="id" />
<TextField source="title" />
<TextField source="views" />
</Datagrid>
</List>
);
Return Value
The useListContext
hook returns an object with the following keys:
const {
// fetched data
data, // an array of the list records, e.g. [{ id: 123, title: 'hello world' }, { ... }]
total, // the total number of results for the current filters, excluding pagination. Useful to build the pagination controls, e.g. 23
isFetching, // boolean that is true while the data is being fetched, and false once the data is fetched
isLoading, // boolean that is true until the data is available for the first time
// pagination
page, // the current page. Starts at 1
perPage, // the number of results per page. Defaults to 25
setPage, // a callback to change the page, e.g. setPage(3)
setPerPage, // a callback to change the number of results per page, e.g. setPerPage(25)
hasPreviousPage, // boolean, true if the current page is not the first one
hasNextPage, // boolean, true if the current page is not the last one
// sorting
sort, // a sort object { field, order }, e.g. { field: 'date', order: 'DESC' }
setSort, // a callback to change the sort, e.g. setSort({ field: 'name', order: 'ASC' })
// filtering
filterValues, // a dictionary of filter values, e.g. { title: 'lorem', nationality: 'fr' }
displayedFilters, // a dictionary of the displayed filters, e.g. { title: true, nationality: true }
setFilters, // a callback to update the filters, e.g. setFilters(filters, displayedFilters)
showFilter, // a callback to show one of the filters, e.g. showFilter('title', defaultValue)
hideFilter, // a callback to hide one of the filters, e.g. hideFilter('title')
// record selection
selectedIds, // an array listing the ids of the selected rows, e.g. [123, 456]
onSelect, // callback to change the list of selected rows, e.g. onSelect([456, 789])
onToggleItem, // callback to toggle the selection of a given record based on its id, e.g. onToggleItem(456)
onUnselectItems, // callback to clear the selection, e.g. onUnselectItems();
// misc
defaultTitle, // the translated title based on the resource, e.g. 'Posts'
resource, // the resource name, deduced from the location. e.g. 'posts'
refetch, // callback for fetching the list data again
} = useListContext();
Declarative Version
useListContext
often forces you to create a new component just to access the list context. If you prefer a declarative approach based on render props, you can use the <WithListContext>
component instead:
import { WithListContext } from 'react-admin';
import { Typography } from '@mui/material';
export const Aside = () => (
<WithListContext render={({ data, isLoading }) =>
!isLoading && (
<div>
<Typography variant="h6">Posts stats</Typography>
<Typography variant="body2">
Total views: {data.reduce((sum, post) => sum + post.views, 0)}
</Typography>
</div>
)} />
);
TypeScript
The useListContext
hook accepts a generic parameter for the record type:
import { Typography } from '@mui/material';
import { List, Datagrid, TextField, useListContext } from 'react-admin';
type Post = {
id: number;
title: string;
views: number;
};
export const Aside = () => {
const { data: posts, isLoading } = useListContext<Post>();
if (isLoading) return null;
return (
<div>
<Typography variant="h6">Posts stats</Typography>
<Typography variant="body2">
{/* TypeScript knows that posts is of type Post[] */}
Total views: {posts.reduce((sum, post) => sum + post.views, 0)}
</Typography>
</div>
);
};
export const PostList = () => (
<List aside={<Aside />}>
<Datagrid>
<TextField source="id" />
<TextField source="title" />
<TextField source="views" />
</Datagrid>
</List>
);
Recipes
You can find many usage examples of useListContext
in the documentation, including:
- Adding a Side Component with
<List actions>
- Building a Custom Actions Bar via
<List actions>
- Building a Custom Empty Page via
<List empty>
- Building a Custom Filter
- Building a Custom Sort Control
- Building a Custom Pagination Control
- Building a Custom Iterator
Tip: <ReferenceManyField>
, as well as other relationship-related components, also implement a ListContext
. That means you can use a <Datagrid>
of a <Pagination>
inside these components!