Laravel Nova Actions BelongsTo field not working - laravel

Question

I have this simple action:
/**
* Perform the action on the given models.
*
* #param \Laravel\Nova\Fields\ActionFields $fields
* #param \Illuminate\Support\Collection $models
* #return mixed
*/
public function handle(ActionFields $fields, Collection $models)
{
foreach ($models as $model) {
$model->update([
'user_id' => $fields->user
]);
}
}
/**
* Get the fields available on the action.
*
* #return array
*/
public function fields()
{
return [
BelongsTo::make('User', 'user', User::class),
];
}
At first, it seems fine, but when I select User from BelongsTo relation and try to save exception is throwing:
Argument 1 passed to Laravel\Nova\Fields\BelongsTo::getRelationForeignKeyName() must be an instance of Illuminate\Database\Eloquent\Relations\Relation, instance of Illuminate\Support\Fluent given, called in /Users/rd/Sites/bns-crm/vendor/laravel/nova/src/Fields/BelongsTo.php on line 212

Answer 1

Yes i know i'm late but - here's a solution for this:
Use a Select-Field instead of BelongsTo and Pluck your options to build Key-Value pairs:
public function fields()
{
return [
Select::make('debitor')->options(\App\Models\Debitor::pluck('Name', 'id'))
];
}
Then in the handle you should geht the ids in $fields:
public function handle(ActionFields $fields, Collection $models) {
Log::info($fields);
}

Answer 2

Maybe I'm late, but, for the ones like me wanting to use the BelongsTo searchable field because the model they want to search in contains too much records to pack them in a normal Select field here is the solution I found:
Create a class in App\Nova\Fields with this code:
<?php
namespace App\Nova\Fields;
use Laravel\Nova\Fields\BelongsTo;
use Laravel\Nova\Http\Requests\NovaRequest;
class BelongsToForActions extends BelongsTo
{
public function fillForAction(NovaRequest $request, $model)
{
$attribute = $this->attribute;
if ($request->exists($attribute)) {
$value = $request[ $attribute ];
$model->{$attribute} = $this->isNullValue($value) ? null : $value;
}
}
}
Then use it like you would use a normal BelongsTo field. Just remember to fill the 3 arguments on the make, so, for example:
BelongsToForActions::make('User', 'relation', \App\Nova\User::class)->searchable()
Remember that 'relation' must exist.

Answer 3

Check your namespaces. Did you imported right class? User class must be resource class
public function fields()
{
return [
BelongsTo::make('User', 'user', User::class),
];
}

Answer 4

I actually fixed this by mocking the key value pair used in this relationship.
First I build an array with the ID column as key and the name column as value.
$clients = Client::all()
->keyBy('id')
->map(fn($client): string => $client['name'])
->toArray();
Then I use the Select nova field to display it.
Select::make('Klant', 'client')
->searchable()
->options($clients)
->rules('required'),