如何在react - admin的referenceinput中设置默认值

import React from 'react';
import { FormDataConsumer, ReferenceInput, SelectInput } from 'react-admin';

const MyForm = () => (
    <form>
        <ReferenceInput source="category_id" reference="categories">
            <SelectInput optionText="name" />
        </ReferenceInput>
        <FormDataConsumer>
            {({ formData, ...rest }) => (
                <ReferenceInput
                    source="subcategory_id"
                    reference="subcategories"
                    filter={{ category_id: formData.category_id }}
                    {...rest}
                >
                    <SelectInput optionText="name" />
                </ReferenceInput>
            )}
        </FormDataConsumer>
    </form>
);

export default MyForm;