Add server side validation support

cypress/e2e/edit.cy.js

@@ -319,7 +319,7 @@ describe('Edit Page', () => {
         cy.get('body').click('left'); // dismiss notification
 
         cy.get('div[role="alert"]').should(el =>
-            expect(el).to.have.text('this title cannot be used')
+            expect(el).to.have.text('The form is invalid')
         );
 
         cy.get(ListPagePosts.elements.recordRows)

docs/Validation.md

@@ -362,52 +362,88 @@ const CustomerCreate = () => (
 
 ## Server-Side Validation
 
-You can use the errors returned by the dataProvider mutation as a source for the validation. In order to display the validation errors, a custom `save` function needs to be used:
+Server-side validation is supported out of the box for `pessimistic` mode only. It requires that the dataProvider throws an error with the following shape:
 
-{% raw %}
-```jsx
-import * as React from 'react';
-import { useCallback } from 'react';
-import { Create, SimpleForm, TextInput, useCreate, useRedirect, useNotify } from 'react-admin';
-
-export const UserCreate = () => {
-    const redirect = useRedirect();
-    const notify = useNotify();
-
-    const [create] = useCreate();
-    const save = useCallback(
-        async values => {
-            try {
-                await create(
-                    'users',
-                    { data: values },
-                    { returnPromise: true }
-                );
-                notify('ra.notification.created', {
-                    type: 'info',
-                    messageArgs: { smart_count: 1 },
-                });
-                redirect('list');
-            } catch (error) {
-                if (error.body.errors) {
-                    // The shape of the returned validation errors must match the shape of the form
-                    return error.body.errors;
+```
+{
+    body: {
+        errors: {
+            title: 'An article with this title already exists. The title must be unique.',
+            date: 'The date is required',
+            tags: { message: "The tag 'agrriculture' doesn't exist" },
+        }
+    }
+}
+```
+
+**Tip**: The shape of the returned validation errors must match the form shape: each key needs to match a `source` prop.
+
+**Tip**: The returned validation errors might have any validation format we support (simple strings, translation strings or translation objects with a `message` attribute) for each key.
+
+**Tip**: If your data provider leverages React Admin's [`httpClient`](https://marmelab.com/react-admin/DataProviderWriting.html#example-rest-implementation), all error response bodies are wrapped and thrown as `HttpError`. This means your API only needs to return an invalid response with a json body containing the `errors` key.
+
+```js
+import { fetchUtils } from "react-admin";
+
+const httpClient = fetchUtils.fetchJson;
+
+const apiUrl = 'https://my.api.com/';
+/*
+  Example response from the API when there are validation errors:
+
+  {
+    "errors": {
+      "title": "An article with this title already exists. The title must be unique.",
+      "date": "The date is required",
+      "tags": { "message": "The tag 'agrriculture' doesn't exist" },
+    }
+  }
+*/
+
+const myDataProvider = {
+    create: (resource, params) =>
+        httpClient(`${apiUrl}/${resource}`, {
+            method: 'POST',
+            body: JSON.stringify(params.data),
+        }).then(({ json }) => ({
+            data: { ...params.data, id: json.id },
+        })),
+}
+```
+
+**Tip:** If you are not using React Admin's `httpClient`, you can still wrap errors in an `HttpError` to return them with the correct shape:
+
+```js
+import { HttpError } from 'react-admin'
+
+const myDataProvider = {
+    create: async (resource, { data }) => {
+        const response = await fetch(`${process.env.API_URL}/${resource}`, {
+            method: 'POST',
+            body: JSON.stringify(data),
+        });
+
+        const body = response.json();
+        /*
+            body should be something like:
+            {
+                errors: {
+                    title: "An article with this title already exists. The title must be unique.",
+                    date: "The date is required",
+                    tags: { message: "The tag 'agrriculture' doesn't exist" },
                 }
             }
-        },
-        [create, notify, redirect]
-    );
-
-    return (
-        <Create>
-            <SimpleForm onSubmit={save}>
-                <TextInput label="First Name" source="firstName" />
-                <TextInput label="Age" source="age" />
-            </SimpleForm>
-        </Create>
-    );
-};
-```
-{% endraw %}
+        */
+
+        if (status < 200 || status >= 300) {
+            throw new HttpError(
+                (body && body.message) || status,
+                status,
+                body
+            );
+        }
 
-**Tip**: The shape of the returned validation errors must correspond to the form: a key needs to match a `source` prop.
+        return body;
+    }
+}
+```

examples/simple/src/dataProvider.tsx

@@ -1,5 +1,5 @@
 import fakeRestProvider from 'ra-data-fakerest';
-import { DataProvider, withLifecycleCallbacks } from 'react-admin';
+import { DataProvider, HttpError, withLifecycleCallbacks } from 'react-admin';
 import get from 'lodash/get';
 import data from './data';
 import addUploadFeature from './addUploadFeature';
@@ -96,7 +96,13 @@ const sometimesFailsDataProvider = new Proxy(uploadCapableDataProvider, {
             params.data &&
             params.data.title === 'f00bar'
         ) {
-            return Promise.reject(new Error('this title cannot be used'));
+            return Promise.reject(
+                new HttpError('The form is invalid', 400, {
+                    errors: {
+                        title: 'this title cannot be used',
+                    },
+                })
+            );
         }
         return uploadCapableDataProvider[name](resource, params);
     },

packages/ra-core/src/controller/create/useCreateController.spec.tsx

@@ -13,6 +13,7 @@ import {
     SaveContextProvider,
     useRegisterMutationMiddleware,
 } from '../saveContext';
+import { DataProvider } from '../..';
 
 describe('useCreateController', () => {
     describe('getRecordFromLocation', () => {
@@ -502,4 +503,33 @@ describe('useCreateController', () => {
             expect.any(Function)
         );
     });
+
+    it('should return errors from the create call', async () => {
+        const create = jest.fn().mockImplementationOnce(() => {
+            return Promise.reject({ body: { errors: { foo: 'invalid' } } });
+        });
+        const dataProvider = ({
+            create,
+        } as unknown) as DataProvider;
+        let saveCallback;
+        render(
+            <CoreAdminContext dataProvider={dataProvider}>
+                <CreateController {...defaultProps}>
+                    {({ save, record }) => {
+                        saveCallback = save;
+                        return <div />;
+                    }}
+                </CreateController>
+            </CoreAdminContext>
+        );
+        await new Promise(resolve => setTimeout(resolve, 10));
+        let errors;
+        await act(async () => {
+            errors = await saveCallback({ foo: 'bar' });
+        });
+        expect(errors).toEqual({ foo: 'invalid' });
+        expect(create).toHaveBeenCalledWith('posts', {
+            data: { foo: 'bar' },
+        });
+    });
 });

packages/ra-core/src/controller/create/useCreateController.ts

@@ -6,7 +6,11 @@ import { Location } from 'history';
 import { UseMutationOptions } from 'react-query';
 
 import { useAuthenticated } from '../../auth';
-import { useCreate, UseCreateMutateParams } from '../../dataProvider';
+import {
+    HttpError,
+    useCreate,
+    UseCreateMutateParams,
+} from '../../dataProvider';
 import { useRedirect, RedirectionSideEffect } from '../../routing';
 import { useNotify } from '../../notification';
 import { SaveContextValue, useMutationMiddlewares } from '../saveContext';
@@ -74,7 +78,7 @@ export const useCreateController = <
     const [create, { isLoading: saving }] = useCreate<
         RecordType,
         MutationOptionsError
-    >(resource, undefined, otherMutationOptions);
+    >(resource, undefined, { ...otherMutationOptions, returnPromise: true });
 
     const save = useCallback(
         (
@@ -91,55 +95,67 @@ export const useCreateController = <
                     : transform
                     ? transform(data)
                     : data
-            ).then((data: Partial<RecordType>) => {
+            ).then(async (data: Partial<RecordType>) => {
                 const mutate = getMutateWithMiddlewares(create);
-                mutate(
-                    resource,
-                    { data, meta },
-                    {
-                        onSuccess: async (data, variables, context) => {
-                            if (onSuccessFromSave) {
-                                return onSuccessFromSave(
-                                    data,
-                                    variables,
-                                    context
-                                );
-                            }
-                            if (onSuccess) {
-                                return onSuccess(data, variables, context);
-                            }
+                try {
+                    await mutate(
+                        resource,
+                        { data, meta },
+                        {
+                            onSuccess: async (data, variables, context) => {
+                                if (onSuccessFromSave) {
+                                    return onSuccessFromSave(
+                                        data,
+                                        variables,
+                                        context
+                                    );
+                                }
+                                if (onSuccess) {
+                                    return onSuccess(data, variables, context);
+                                }
 
-                            notify('ra.notification.created', {
-                                type: 'info',
-                                messageArgs: { smart_count: 1 },
-                            });
-                            redirect(finalRedirectTo, resource, data.id, data);
-                        },
-                        onError: onErrorFromSave
-                            ? onErrorFromSave
-                            : onError
-                            ? onError
-                            : (error: Error | string) => {
-                                  notify(
-                                      typeof error === 'string'
-                                          ? error
-                                          : error.message ||
-                                                'ra.notification.http_error',
-                                      {
-                                          type: 'error',
-                                          messageArgs: {
-                                              _:
-                                                  typeof error === 'string'
-                                                      ? error
-                                                      : error && error.message
-                                                      ? error.message
-                                                      : undefined,
-                                          },
-                                      }
-                                  );
-                              },
+                                notify('ra.notification.created', {
+                                    type: 'info',
+                                    messageArgs: { smart_count: 1 },
+                                });
+                                redirect(
+                                    finalRedirectTo,
+                                    resource,
+                                    data.id,
+                                    data
+                                );
+                            },
+                            onError: onErrorFromSave
+                                ? onErrorFromSave
+                                : onError
+                                ? onError
+                                : (error: Error | string) => {
+                                      notify(
+                                          typeof error === 'string'
+                                              ? error
+                                              : error.message ||
+                                                    'ra.notification.http_error',
+                                          {
+                                              type: 'error',
+                                              messageArgs: {
+                                                  _:
+                                                      typeof error === 'string'
+                                                          ? error
+                                                          : error &&
+                                                            error.message
+                                                          ? error.message
+                                                          : undefined,
+                                              },
+                                          }
+                                      );
+                                  },
+                        }
+                    );
+                } catch (error) {
+                    if ((error as HttpError).body?.errors != null) {
+                        return (error as HttpError).body.errors;
                     }
-                );
+                }
             }),
         [
             create,

packages/ra-core/src/controller/edit/useEditController.spec.tsx

@@ -906,4 +906,38 @@ describe('useEditController', () => {
             expect.any(Function)
         );
     });
+
+    it('should return errors from the update call in pessimistic mode', async () => {
+        let post = { id: 12 };
+        const update = jest.fn().mockImplementationOnce(() => {
+            return Promise.reject({ body: { errors: { foo: 'invalid' } } });
+        });
+        const dataProvider = ({
+            getOne: () => Promise.resolve({ data: post }),
+            update,
+        } as unknown) as DataProvider;
+        let saveCallback;
+        render(
+            <CoreAdminContext dataProvider={dataProvider}>
+                <EditController {...defaultProps} mutationMode="pessimistic">
+                    {({ save, record }) => {
+                        saveCallback = save;
+                        return <>{JSON.stringify(record)}</>;
+                    }}
+                </EditController>
+            </CoreAdminContext>
+        );
+        await screen.findByText('{"id":12}');
+        let errors;
+        await act(async () => {
+            errors = await saveCallback({ foo: 'bar' });
+        });
+        expect(errors).toEqual({ foo: 'invalid' });
+        screen.getByText('{"id":12}');
+        expect(update).toHaveBeenCalledWith('posts', {
+            id: 12,
+            data: { foo: 'bar' },
+            previousData: { id: 12 },
+        });
+    });
 });