[Doc] Fix ReferenceOneField doc

Author: fzaninotto

docs/ReferenceOneField.md

@@ -59,14 +59,16 @@ const BookShow = () => (
 | -------------- | -------- | ------------------------------------------- | -------------------------------- | ----------------------------------------------------------------------------------- |
 | `reference`    | Required | `string`                                    | -                                | The name of the resource for the referenced records, e.g. 'book_details'            |
 | `target`       | Required | string                                      | -                                | Target field carrying the relationship on the referenced resource, e.g. 'book_id'   |
-| `children`     | Optional | `Element`                                   | -                                | The Field element used to render the referenced record                              |
-| `render`     | Optional | `(ReferenceFieldContext) => Element`                                   | -                                | A function that takes the `ReferenceFieldContext` and returns a React element                              |
+| `children`     | Optional * | `Element`                                   | -                                | The Field element used to render the referenced record                              |
+| `render`     | Optional * | `(ReferenceFieldContext) => Element`                                   | -                                | A function that takes the `ReferenceFieldContext` and returns a React element                              |
 | `empty`        | Optional | `ReactNode`                         | -                                | The text or element to display when the referenced record is empty                   |
 | `filter`       | Optional | `Object`                                    | `{}`                             | Used to filter referenced records                                                   |
 | `link`         | Optional | `string | Function`                         | `edit`                           | Target of the link wrapping the rendered child. Set to `false` to disable the link. |
 | `queryOptions` | Optional | [`UseQueryOptions`](https://tanstack.com/query/v5/docs/react/reference/useQuery) | `{}` | `react-query` client options |
 | `sort`         | Optional | `{ field: String, order: 'ASC' or 'DESC' }` | `{ field: 'id', order: 'ASC' }`  | Used to order referenced records                                                    |
 
+`*` You must provide either `children` or `render`.
+
 `<ReferenceOneField>` also accepts the [common field props](./Fields.md#common-field-props).
 
 ## `children`
@@ -81,34 +83,6 @@ For instance, if you want to render both the genre and the ISBN for a book:
 </ReferenceOneField>
 ```
 
-
-## `render`
-
-Alternatively to children you can pass a `render` function prop to `<ReferenceOneFieldBase>`. The `render` function prop will receive the `ReferenceFieldContext` as its argument, allowing to inline the render logic.
-When receiving a `render` function prop the `<ReferenceOneFieldBase>` component will ignore the children property.
-
-```jsx
-<ReferenceOneField
-    reference="book_details"
-    target="book_id"
-    render={({ isPending, error, referenceRecord }) => {
-        if (isPending) {
-            return <Typography>Loading...</Typography>;
-        }
-
-        if (error) {
-            return <Typography className="error" >{error.toString()}</Typography>;
-        }
-        return (
-            <div>
-                <Typography>{referenceRecord ? referenceRecord.genre : ''}</Typography>
-                <Typography>{referenceRecord ? referenceRecord.ISBN : ''}</Typography>
-            </div>
-        );
-    }}
-/>
-```
-
 ## `empty`
 
 Use `empty` to customize the text displayed when the related record is empty.
@@ -213,6 +187,38 @@ For instance, if you want to display the details of a given book, the `reference
 </ReferenceOneField>
 ```
 
+## `render`
+
+Alternatively to `children`, you can pass a `render` prop to `<ReferenceOneField>`. It will receive the `ReferenceFieldContext` as its argument, and should return a React node.
+
+This allows to inline the render logic for the related record.
+
+```tsx
+<ReferenceOneField
+    reference="book_details"
+    target="book_id"
+    render={({ isPending, error, referenceRecord }) => {
+        if (isPending) {
+            return <p>Loading...</p>;
+        }
+        if (error) {
+            return <p className="error" >{error.toString()}</p>;
+        }
+        if (!referenceRecord) {
+            return <p className="error">No details found</p>;
+        }
+        return (
+            <dl>
+                <dt>Genre</dt>
+                <dd>{referenceRecord.genre}</dd>
+                <dt>ISBN</dt>
+                <dd>{referenceRecord.ISBN}</dd>
+            </dl>
+        );
+    }}
+/>
+```
+
 ## `sort`
 
 You can also use `<ReferenceOneField>` in a one-to-many relationship. In that case, the first record will be displayed. This is where the `sort` prop comes in handy. It allows you to select the appropriate record to display.