is there a way to access model attributes while using with method

hey guys i have a problem. im trying to eagerload my basket items by defining a scope:

public function apply(Builder $builder, Model $model)
{
    $builder->with(['product']);
}

and my product relation inside basket model is like below:

public function product()
{
    if ($this->used_product_id) {
        return $this->belongsTo(UsedProduct::class, 'used_product_id', 'id');
    } else {
        return $this->belongsTo(Product::class, 'product_id', 'id');
    }
}

but the problem is when using with() $this->used_product_id returns null and i cant get access to my current model attributes. do you have any solution?

Solution 1:

I would try something like this:

class Basket extends Model
{

    public function newProduct()
    {
        return $this->belongsTo(Product::class, 'product_id', 'id');
    }

    public function usedProduct()
    {
        return $this->belongsTo(UsedProduct::class, 'used_product_id', 'id');
    }

    public function product()
    {
        return $this->usedProduct ?? $this->newProduct ?? null;
    }

}

To make sure that the products are eager loaded, you'd have to load it with both products, like

Basket::with(['newProduct','usedProduct'])->get()

Solution 2:

You could define your scope like an anonymous global scope

class Basket extends Model
{
    protected static function booted()
    {
        static::addGlobalScope('withProduct', function (Builder $builder) {
            $builder->with('product');
        });
    }

    public function product()
    {
        if ($this->used_product_id) {
            return $this->belongsTo(UsedProduct::class, 'used_product_id', 'id');
        } else {
            return $this->belongsTo(Product::class, 'product_id', 'id');
        }
    }
}

Or use the $with property.

class Basket extends Model
{
    /**
     * The relations to eager load on every query.
     *
     * @var array
     */
    protected $with = ['product'];

    public function product()
    {
        if ($this->used_product_id) {
            return $this->belongsTo(UsedProduct::class, 'used_product_id', 'id');
        } else {
            return $this->belongsTo(Product::class, 'product_id', 'id');
        }
    }
}