<ReferenceManyInput>

Use <ReferenceManyInput> in an <Edit> or <Create> view to edit one-to-many relationships, e.g. to edit the variants of a product in the product edition view. It’s an Enterprise Edition component, part of the @react-admin/ra-relationships package.

<ReferenceManyInput> fetches the related records, and renders them in a sub-form. When users add, remove or update related records, the <ReferenceManyInput> component stores these changes locally. When the users actually submit the form, <ReferenceManyInput> computes a diff with the existing relationship, and sends the related changes (additions, deletions, and updates) to the server.

Tip: If you need to edit an array of embedded records, i.e. if the variants above are actually embedded in the product record, you should use <ArrayInput> instead.

Tip: If there is only one related record, you should use <ReferenceOneInput> instead.

Usage

An example one-to-many relationship can be found in ecommerce systems: a product has many variants.

┌───────────────┐       ┌──────────────┐
│ products      │       │ variants     │
│---------------│       │--------------│
│ id            │───┐   │ id           │
│ name          │   └──╼│ product_id   │
│ price         │       │ sku          │
│ category_id   │       │ size         │
└───────────────┘       │ color        │
                        │ stock        │
                        └──────────────┘

You probably want to let users edit variants directly from the product Edition view (instead of having to go to the variant Edition view). <ReferenceManyInput> allows to do that.

import {
    Edit,
    SimpleForm,
    TextInput,
    NumberInput,
    ReferenceInput,
    SelectInput,
} from 'react-admin';
import { ReferenceManyInput } from '@react-admin/ra-relationships';

const ProductEdit = () => (
    <Edit mutationMode="optimistic">
        <SimpleForm>
            <TextInput source="name" />
            <NumberInput source="price" />
            <ReferenceInput source="category_id" reference="categories" />
            <ReferenceManyInput reference="variants" target="product_id">
                <SimpleFormIterator inline disableReordering>
                    <TextInput source="sku" />
                    <SelectInput source="size" choices={sizes} />
                    <SelectInput source="color" choices={colors} />
                    <NumberInput source="stock" defaultValue={0} />
                </SimpleFormIterator>
            </ReferenceManyInput>
        </SimpleForm>
    </Edit>
);

<ReferenceManyInput> requires a reference and a target prop to know which entity to fetch, and a child component (usually a <SimpleFormIterator>) to edit the relationship.

<ReferenceManyInput> persists the changes in the reference records (variants in the above example) after persisting the changes in the main resource (product in the above example). This means that you can also use <ReferenceManyInput> in <Create> views.

Tip: <ReferenceManyInput> cannot be used with undoable mutations. You have to set mutationMode="optimistic" or mutationMode="pessimistic" in the parent <Edit>, as in the example above.

Props

children

<ReferenceManyInput> creates an <ArrayInputContext>, so it accepts the same type of children as <ArrayInput>: a Form iterator. React-admin bundles one such iterator: <SimpleFormIterator>. It renders one row for each related record, giving the user the ability to add, remove, or edit related records.

<ReferenceManyInput reference="variants" target="product_id">
    <SimpleFormIterator disableReordering>
        <TextInput source="sku" />
        <SelectInput source="size" choices={sizes} />
        <SelectInput source="color" choices={colors} />
        <NumberInput source="stock" defaultValue={0} />
    </SimpleFormIterator>
</ReferenceManyInput>

Check out the <SimpleFormIterator> documentation for more details.

defaultValue

When the current record has no related records, <ReferenceManyInput> renders an empty list with an “Add” button to add related records.

You can use the defaultValue prop to populate the list of related records in that case. It must be an array of objects.

<ReferenceManyInput
    reference="variants"
    target="product_id"
    defaultValue={[
        { sku: 'SKU_1', size: 'S', color: 'black', stock: 0 },
        { sku: 'SKU_2', size: 'M', color: 'black', stock: 0 },
        { sku: 'SKU_3', size: 'L', color: 'black', stock: 0 },
        { sku: 'SKU_4', size: 'XL', color: 'black', stock: 0 },
    ]}
>
    <SimpleFormIterator disableReordering>
        <TextInput source="sku" />
        <SelectInput source="size" choices={sizes} />
        <SelectInput source="color" choices={colors} />
        <NumberInput source="stock" defaultValue={0} />
    </SimpleFormIterator>
</ReferenceManyInput>

filter

You can filter the query used to populate the current values. Use the filter prop for that.

<ReferenceManyInput
    reference="variants"
    target="product_id"
    filter={{ is_published: true }}
>
    ...
</ReferenceManyInput>

helperText

If you need to display a text below the input (usually to explain the expected data to the user), use the helperText prop.

<ReferenceManyInput
    reference="variants"
    target="product_id"
    helperText="Enter at least 5 variants for each product"
>
    ...
</ReferenceManyInput>

label

By default, <ReferenceManyInput> humanizes the reference name to build a label. You can customize the label by passing the label prop.

<ReferenceManyInput
    reference="variants"
    target="product_id"
    label="Product variants"
>
    ...
</ReferenceManyInput>

React-admin uses the i18n system to translate the label, so you can use translation keys to have one label for each language supported by the interface:

<ReferenceManyInput
    reference="variants"
    target="product_id"
    label="resource.products.fields.variants"
>
    ...
</ReferenceManyInput>

perPage

By default, react-admin restricts the possible values to 25 and displays no pagination control. You can change the limit by setting the perPage prop:

<ReferenceManyInput reference="variants" target="product_id" perPage={10}>
    ...
</ReferenceManyInput>

reference

The name of the resource to fetch for the related records.

For instance, if you want to display the variants of a given product, the reference name should be variants:

<ReferenceManyInput reference="books" target="author_id">
    ...
</ReferenceManyInput>

sort

By default, related records appear ordered by id desc. You can change this order by setting the sort prop (an object with field and order properties).

<ReferenceManyInput
    reference="variants"
    target="product_id"
    sort={{ field: 'sku', order: 'ASC' }}
>
   ...
</ReferenceManyInput>

source

By default, <ReferenceManyInput> ferchers the references for which the target field equals the current record id. You can customize the field that carries the identity of the current record by setting the source prop.

<ReferenceManyInput reference="variants" target="product_id" source="_id">
    ...
</ReferenceManyInput>

sx

You can override the style of the root component (a Material UI <FormControl>) and its child components by setting the sx prop.

<ReferenceManyInput
    reference="variants"
    target="product_id"
    sx={{ marginLeft: 2 }}
>
   ...
</ReferenceManyInput>

target

Name of the field carrying the relationship on the referenced resource. For instance, if a product has many variants, and each variant resource exposes an product_id field, the target would be author_id.

<ReferenceManyInput reference="variants" target="product_id">
    ...
</ReferenceManyInput>

validate

Just like regular inputs, you can use the validate prop to define custom validation rules for the list of references.

import { minLength } from 'react-admin';

const ProductEdit = () => (
    <Edit mutationMode="optimistic">
        <SimpleForm>
            <TextInput source="name" />
            <ReferenceInput source="category_id" reference="categories" />
            <ReferenceManyInput
                reference="variants"
                target="product_id"
                validate={[minLength(2, 'Please add at least 2 variants')]}
            >
                ...
            </ReferenceManyInput>
        </SimpleForm>
    </Edit>
);

Limitations

• <ReferenceManyInput> cannot be used inside an <ArrayInput> or a <ReferenceOneInput>.
• <ReferenceManyInput> does not support reordering its items so you should set the disableReordering prop on <SimpleFormIterator> if you use it.
• <ReferenceManyInput> cannot be used with undoable mutations in a <Create> view.
• <ReferenceManyInput> cannot have a <ReferenceOneInput> or a <ReferenceManyToManyInput> as one of its children.
• <ReferenceManyInput> does not support server side validation.

Changing An Item’s Value Programmatically

You can leverage react-hook-form’s setValue method to change an item’s value programmatically.

However you need to know the name under which the input was registered in the form, and this name is dynamically generated depending on the index of the item in the array.

To get the name of the input for a given index, you can leverage the SourceContext created by react-admin, which can be accessed using the useSourceContext hook.

This context provides a getSource function that returns the effective source for an input in the current context, which you can use as input name for setValue.

Here is an example where we leverage getSource and setValue to prefill the email input when the ‘Prefill email’ button is clicked:

import { SimpleFormIterator, TextInput, useSourceContext } from 'react-admin';
import { ReferenceManyInput } from '@react-admin/ra-relationships';
import { useFormContext } from 'react-hook-form';
import { Button } from '@mui/material';

const PrefillEmail = () => {
    const sourceContext = useSourceContext();
    const { setValue, getValues } = useFormContext();

    const onClick = () => {
        const firstName = getValues(sourceContext.getSource('first_name'));
        const lastName = getValues(sourceContext.getSource('last_name'));
        const email = `${
            firstName ? firstName.toLowerCase() : ''
        }.${lastName ? lastName.toLowerCase() : ''}@school.com`;
        setValue(sourceContext.getSource('email'), email);
    };

    return (
        <Button onClick={onClick} size="small" sx={{ minWidth: 140 }}>
            Prefill email
        </Button>
    );
};

const StudentsInput = () => (
    <ReferenceManyInput
        reference="students"
        target="teacher_id"
        sort={{ field: 'last_name', order: 'ASC' }}
    >
        <SimpleFormIterator inline disableReordering>
            <TextInput source="first_name" helperText={false} />
            <TextInput source="last_name" helperText={false} />
            <TextInput source="email" helperText={false} />
            <PrefillEmail />
        </SimpleFormIterator>
    </ReferenceManyInput>
);

Tip: If you only need the item’s index, you can leverage the useSimpleFormIteratorItem hook instead.