> ## Documentation Index
> Fetch the complete documentation index at: https://docs.eloquentfiltering.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Relations Allowed Fields

## Overview

By default, when specifying an `Filter::relation()` or `Filter::morphRelation()`, fields within that relationship are not included in the allowed filter list.

You can specify allowed filters inside a relation in two ways.

### `includeRelationFields()`

Use `->includeRelationFields()` on `Filter::relation()` or `Filter::morphRelation()`.

<Note>
  This method instructs the package to look for `AllowedField` filters within the `allowedFilters()` method of the relation model.
</Note>

<Warning>
  The relationship method **MUST** have return type specified, and the related model **MUST** also implement `IsFilterable`.
</Warning>

```php {5} theme={null}
public function allowedFilters(): AllowedFilterList
{
    return Filter::only(
        Filter::relation('manufacturer', [FilterType::HAS])
            ->includeRelationFields()
    );
}
```

For `Filter::morphRelation()`, you should specify the models for which to include the relation fields for.

```php {7-10} theme={null}
public function allowedFilters(): AllowedFilterList
{
    return Filter::only(
        Filter::morphRelation(
            'subscribable',
            [FilterType::HAS_MORPH],
        )->includeRelationFields([
            FoodDeliveryService::class,
            Saas::class,
        ])
    );
}
```

### Define `allowedFilters`

Alternatively, if you don't want to use `->includeRelationFields()`, you can define `allowedFilters` for each `Filter::relation()` and `Filter::morphType()`.

```php {7-9} theme={null}
public function allowedFilters(): AllowedFilterList
{
    return Filter::only(
        Filter::relation(
            target: 'manufacturer',
            types: [FilterType::HAS],
            allowedFilters: Filter::only(
                Filter::field('name', [FilterType::LIKE])
            )
        )
    );
}
```

```php {7-9,13-15} theme={null}
public function allowedFilters(): AllowedFilterList
{
    return Filter::only(
        Filter::morphRelation('subscribable', [FilterType::HAS_MORPH],
            Filter::morphType(
                type: FoodDeliveryService::class,
                allowedFilters: Filter::only(
                    Filter::field('name', [FilterType::EQUAL])
                )
            ),
            Filter::morphType(
                type: Saas::class,
                allowedFilters: Filter::only(
                    Filter::field('name', [FilterType::EQUAL])
                )
            ),
        )
    );
}
```