Add ListContext to ReferenceArrayInput

docs/Inputs.md

@@ -1406,7 +1406,7 @@ http://myapi.com/tags?id=[1,23,4]
 http://myapi.com/tags?page=1&perPage=25
 ```
 
-Once it receives the deduplicated reference resources, this component delegates rendering to a subcomponent, to which it passes the possible choices as the `choices` attribute.
+Once it receives the deduplicated reference resources, this component delegates rendering to a subcomponent, by providing the possible choices through the `ReferenceArrayInputContext`. This context value can be accessed with the [`useReferenceArrayInputContext`](#usereferencearrayinputcontext) hook.
 
 This means you can use `<ReferenceArrayInput>` with [`<SelectArrayInput>`](#selectarrayinput), or with the component of your choice, provided it supports the `choices` attribute.
 
@@ -1477,8 +1477,30 @@ You can tweak how this component fetches the possible values using the `perPage`
 ```
 {% endraw %}
 
+In addition to the `ReferenceArrayInputContext`, `<ReferenceArrayInput>` also sets up a `ListContext` providing access to the records from the reference resource in a similar fashion to that of the `<List>` component. This `ListContext` value is accessible with the [`useListContext`](/List.md#uselistcontext) hook.
+
 `<ReferenceArrayInput>` also accepts the [common input props](./Inputs.md#common-input-props).
 
+### `useReferenceArrayInputContext`
+
+The [`<ReferenceArrayInput>`](#referencearrayinput) component take care of fetching the data, and put that data in a context called `ReferenceArrayInputContext` so that it’s available for its descendants. This context also stores filters, pagination, sort state, and provides callbacks to update them.
+
+Any component decendent of `<ReferenceArryInput>` can grab information from the `ReferenceArrayInputContext` using the `useReferenceArrayInputContext` hook. Here is what it returns:
+
+```js
+const {
+    choices, // An array of records matching both the current input value and the filters
+    error, // A potential error that may have occured while fetching the data
+    warning, // A potential warning regarding missing references 
+    loaded, // boolean that is false until the data is available
+    loading, // boolean that is true on mount, and false once the data was fetched
+    setFilter, // a callback to update the filters, e.g. setFilters({ q: 'query' })
+    setPagination, // a callback to change the pagination, e.g. setPagination({ page: 2, perPage: 50 })
+    setSort, // a callback to change the sort, e.g. setSort({ field: 'name', order: 'DESC' })
+    setSortForList, // a callback to set the sort with the same signature as the one from the ListContext. This is required to avoid breaking backward compatibility and will be removed in v4
+} = useReferenceArrayInputContext();
+```
+
 ### `<ReferenceInput>`
 
 Use `<ReferenceInput>` for foreign-key values, for instance, to edit the `post_id` of a `comment` resource. This component fetches the related record (using `dataProvider.getMany()`) as well as possible choices (using `dataProvider.getList()` in the reference resource), then delegates rendering to a subcomponent, to which it passes the possible choices as the `choices` attribute.

packages/ra-core/src/controller/field/useReferenceArrayFieldController.ts

@@ -11,6 +11,7 @@ import usePaginationState from '../usePaginationState';
 import useSelectionState from '../useSelectionState';
 import useSortState from '../useSortState';
 import { useResourceContext } from '../../core';
+import { indexById } from '../../util/indexById';
 
 interface Option {
     basePath: string;
@@ -239,12 +240,4 @@ const useReferenceArrayFieldController = (
     };
 };
 
-const indexById = (records: Record[] = []): RecordMap =>
-    records
-        .filter(r => typeof r !== 'undefined')
-        .reduce((prev, current) => {
-            prev[current.id] = current;
-            return prev;
-        }, {});
-
 export default useReferenceArrayFieldController;

packages/ra-core/src/controller/input/ReferenceArrayInputContext.ts

@@ -0,0 +1,29 @@
+import { createContext } from 'react';
+import { PaginationPayload, Record, SortPayload } from '../../types';
+
+/**
+ * Context which provides access to the useReferenceArrayInput features.
+ *
+ * @example
+ * const ReferenceArrayInput = ({ children }) => {
+ *     const controllerProps = useReferenceArrayInputController();
+ *     return (
+ *         <ReferenceArrayInputContextProvider value={controllerProps}>
+ *             {children}
+ *         </ReferenceArrayInputContextProvider>
+ *     )
+ * }
+ */
+export const ReferenceArrayInputContext = createContext(undefined);
+
+export interface ReferenceArrayInputContextValue {
+    choices: Record[];
+    error?: any;
+    warning?: any;
+    loading: boolean;
+    loaded: boolean;
+    setFilter: (filter: any) => void;
+    setPagination: (pagination: PaginationPayload) => void;
+    setSort: (sort: SortPayload) => void;
+    setSortForList: (sort: string, order?: string) => void;
+}

packages/ra-core/src/controller/input/ReferenceArrayInputContextProvider.tsx

@@ -0,0 +1,31 @@
+import * as React from 'react';
+import { ReactNode } from 'react';
+import {
+    ReferenceArrayInputContext,
+    ReferenceArrayInputContextValue,
+} from './ReferenceArrayInputContext';
+
+/**
+ * Provider for the context which provides access to the useReferenceArrayInput features.
+ *
+ * @example
+ * const ReferenceArrayInput = ({ children }) => {
+ *     const controllerProps = useReferenceArrayInputController();
+ *     return (
+ *         <ReferenceArrayInputContextProvider value={controllerProps}>
+ *             {children}
+ *         </ReferenceArrayInputContextProvider>
+ *     )
+ * }
+ */
+export const ReferenceArrayInputContextProvider = ({
+    children,
+    value,
+}: {
+    children: ReactNode;
+    value: ReferenceArrayInputContextValue;
+}) => (
+    <ReferenceArrayInputContext.Provider value={value}>
+        {children}
+    </ReferenceArrayInputContext.Provider>
+);