laravel nova BelongsToMany - BelongsTo in pivot

Question

In Laravel Nova I have BelongsToMany Relationship (companies - pivot - requests).

In the Pivot table I have some additional columns which I access with the pivot fields (https://nova.laravel.com/docs/1.0/resources/relationships.html#belongstomany) which works great.

But now I have a special case where I have an additional BelongsTo relationship from the pivot table to a third table (states). I tried to define a BelongsTo Field in the pivot Fields, but that is not working.

BelongsToMany::make('Companies', 'companies', Company::class)->fields(new CompanyRequestFields()),

pivot fields:

class CompanyRequestFields
{
    /**
     * Get the pivot fields for the relationship.
     *
     * @return array
     */
    public function __invoke()
    {
        return [
            Number::make('preis'),
            Text::make('bezahlt'),
             BelongsTo::make('State', 'state', States::class),
        ];
    }
}

The error I get:

Call to undefined method Illuminate\Database\Eloquent\Relations\Pivot::state()

The relationship state() actually exists on the pivot Model and there is a Nova resource State class too.

So it looks like this is not supported from PivotFields? Or does anyone know if its possible to accomplish this?

Answer 1

I was not able to make it work with relationship in pivot table, but you can achieve it without a relationship definition like below.

class CompanyRequestFields
{
    public function __invoke()
    {
        $states= \App\State::all()->pluck('name', 'id');

        return [
            ...
            Select::make('State')->options($states),
        ];
    }
}

In \App\Request model

public function companies()
{
    return $this->belongsToMany('App\Company')->withPivot('state');
}

Hope this approach will help you.