Fix useReferenceManyFieldController does not debounce setFilters

docs/ReferenceManyField.md

@@ -111,6 +111,7 @@ This example leverages [`<SingleFieldList>`](./SingleFieldList.md) to display an
 | `pagination` | Optional | `Element` | -       | Pagination element to display pagination controls. empty by default (no pagination) |
 | `perPage`    | Optional | `number`  | 25      | Maximum number of referenced records to fetch                                       |
 | `sort`       | Optional | `{ field, order }` | `{ field: 'id', order: 'DESC' }` | Sort order to use when fetching the related records, passed to `getManyReference()` |
+| `debounce`   | Optional | `number`  | 500     | debounce time in ms for the `setFilters` callbacks                                  |
 
 `<ReferenceManyField>` also accepts the [common field props](./Fields.md#common-field-props), except `emptyText` (use the child `empty` prop instead).
 
@@ -172,6 +173,21 @@ export const AuthorShow = () => (
 );
 ```
 
+## `debounce`
+
+By default, `<ReferenceManyField>` does not refresh the data as soon as the user enters data in the filter form. Instead, it waits for half a second of user inactivity (via `lodash.debounce`) before calling the `dataProvider` on filter change. This is to prevent repeated (and useless) calls to the API.
+
+You can customize the debounce duration in milliseconds - or disable it completely - by passing a `debounce` prop to the `<ReferenceManyField>` component:
+
+```jsx
+// wait 1 seconds instead of 500 milliseconds before calling the dataProvider
+const PostCommentsField = () => (
+    <ReferenceManyField debounce={1000}>
+        ...
+    </ReferenceManyField>
+);
+```
+
 ## `filter`
 
 You can filter the query used to populate the possible values. Use the `filter` prop for that.

packages/ra-core/src/controller/field/useReferenceManyFieldController.spec.tsx

@@ -1,5 +1,5 @@
 import * as React from 'react';
-import { render, screen, waitFor } from '@testing-library/react';
+import { fireEvent, render, screen, waitFor } from '@testing-library/react';
 import expect from 'expect';
 
 import { testDataProvider } from '../../dataProvider/testDataProvider';
@@ -19,7 +19,7 @@ const ReferenceManyFieldController = props => {
 describe('useReferenceManyFieldController', () => {
     it('should set isLoading to true when related records are not yet fetched', async () => {
         const ComponentToTest = ({ isLoading }: { isLoading?: boolean }) => {
-            return <div>isLoading: {isLoading.toString()}</div>;
+            return <div>isLoading: {isLoading?.toString()}</div>;
         };
         const dataProvider = testDataProvider({
             getManyReference: () => Promise.resolve({ data: [], total: 0 }),
@@ -47,7 +47,7 @@ describe('useReferenceManyFieldController', () => {
 
     it('should set isLoading to false when related records have been fetched and there are results', async () => {
         const ComponentToTest = ({ isLoading }: { isLoading?: boolean }) => {
-            return <div>isLoading: {isLoading.toString()}</div>;
+            return <div>isLoading: {isLoading?.toString()}</div>;
         };
         const dataProvider = testDataProvider({
             getManyReference: () =>
@@ -273,4 +273,50 @@ describe('useReferenceManyFieldController', () => {
             );
         });
     });
+
+    it('should take only last change in case of a burst of setFilters calls (case of inputs being currently edited)', async () => {
+        let childFunction = ({ setFilters, filterValues }) => (
+            <input
+                aria-label="search"
+                type="text"
+                value={filterValues.q || ''}
+                onChange={event => {
+                    setFilters({ q: event.target.value });
+                }}
+            />
+        );
+        const dataProvider = testDataProvider();
+        const getManyReference = jest.spyOn(dataProvider, 'getManyReference');
+        render(
+            <CoreAdminContext dataProvider={dataProvider}>
+                <ReferenceManyFieldController
+                    resource="authors"
+                    source="id"
+                    record={{ id: 123, name: 'James Joyce' }}
+                    reference="books"
+                    target="author_id"
+                >
+                    {childFunction}
+                </ReferenceManyFieldController>
+            </CoreAdminContext>
+        );
+        const searchInput = screen.getByLabelText('search');
+
+        fireEvent.change(searchInput, { target: { value: 'hel' } });
+        fireEvent.change(searchInput, { target: { value: 'hell' } });
+        fireEvent.change(searchInput, { target: { value: 'hello' } });
+
+        await waitFor(() => new Promise(resolve => setTimeout(resolve, 600)));
+
+        // Called twice: on load and on filter changes
+        expect(getManyReference).toHaveBeenCalledTimes(2);
+        expect(getManyReference).toHaveBeenCalledWith('books', {
+            target: 'author_id',
+            id: 123,
+            filter: { q: 'hello' },
+            pagination: { page: 1, perPage: 25 },
+            sort: { field: 'id', order: 'DESC' },
+            meta: undefined,
+        });
+    });
 });

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

@@ -1,6 +1,7 @@
 import { useCallback, useEffect, useRef } from 'react';
 import get from 'lodash/get';
 import isEqual from 'lodash/isEqual';
+import lodashDebounce from 'lodash/debounce';
 
 import { useSafeSetState, removeEmpty } from '../../util';
 import { useGetManyReference } from '../../dataProvider';
@@ -15,6 +16,7 @@ import { useResourceContext } from '../../core';
 export interface UseReferenceManyFieldControllerParams<
     RecordType extends RaRecord = RaRecord
 > {
+    debounce?: number;
     filter?: any;
     page?: number;
     perPage?: number;
@@ -61,6 +63,7 @@ export const useReferenceManyFieldController = <
     props: UseReferenceManyFieldControllerParams<RecordType>
 ): ListControllerResult<ReferenceRecordType> => {
     const {
+        debounce = 500,
         reference,
         record,
         target,
@@ -128,14 +131,29 @@ export const useReferenceManyFieldController = <
         },
         [setDisplayedFilters, setFilterValues]
     );
-    const setFilters = useCallback(
-        (filters, displayedFilters) => {
+
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+    const debouncedSetFilters = useCallback(
+        lodashDebounce((filters, displayedFilters) => {
             setFilterValues(removeEmpty(filters));
             setDisplayedFilters(displayedFilters);
             setPage(1);
-        },
+        }, debounce),
         [setDisplayedFilters, setFilterValues, setPage]
     );
+
+    const setFilters = useCallback(
+        (filters, displayedFilters, debounce = true) => {
+            if (debounce) {
+                debouncedSetFilters(filters, displayedFilters);
+            } else {
+                setFilterValues(removeEmpty(filters));
+                setDisplayedFilters(displayedFilters);
+                setPage(1);
+            }
+        },
+        [setDisplayedFilters, setFilterValues, setPage, debouncedSetFilters]
+    );
     // handle filter prop change
     useEffect(() => {
         if (!isEqual(filter, filterRef.current)) {

packages/ra-ui-materialui/src/field/ReferenceManyField.tsx

@@ -67,6 +67,7 @@ export const ReferenceManyField = <
 ) => {
     const {
         children,
+        debounce,
         filter = defaultFilter,
         page = 1,
         pagination = null,
@@ -83,6 +84,7 @@ export const ReferenceManyField = <
         RecordType,
         ReferenceRecordType
     >({
+        debounce,
         filter,
         page,
         perPage,
@@ -108,6 +110,7 @@ export interface ReferenceManyFieldProps<
     RecordType extends Record<string, any> = Record<string, any>
 > extends FieldProps<RecordType> {
     children: ReactNode;
+    debounce?: number;
     filter?: FilterPayload;
     page?: number;
     pagination?: ReactElement;