Allow Custom Pivot Models to Define default Pivot Columns to be Loaded

[sfong22]

Problem

When utilizing custom pivot models with additional pivot attributes, it seems the only way to load pivot attributes is using withPivot when defining the relation. I would like to create self contained custom pivots that always load a subset of defined pivot attributes.

Question

Have I missed other ways to have pivots always load certain pivot attributes without utilizing withPivot when defining the relation?

Use Case

Using the trivial example here,

Custom Pivot

class CustomerOrder extends Pivot
{
    protected $casts = [
        'delivery_datetime' => 'datetime',
    ];

    public function getDeliveryDateAttribute(): string
    {
        return $this->delivery_datetime?->format('Y-m-d');
    }
}

Relation

class Customer extends Model
{
    public function orders(): BelongsToMany
    {
        return $this->belongsToMany(Customer::class)
            ->using(CustomerOrder::class)
            ->withPivot('delivery_datetime');
    }
}

Without the ->withPivot('delivery_date'), when accessing $order->pivot->delivery_date null would be returned even if a delivery date is set in the datastore. There does not seem to be a way to include pivot values to be loaded within the custom pivot model to prevent that oversight. When going through the trouble of creating a custom pivot model, it would be nice for the custom pivot model to be an atomic unit capable of loading its pivot attributes.

Implementation

1. Allow a parameter to be defined on Pivot models called $pivotColumns or something of the sort.
2. Use this value when defining $default columns within aliasedPivotColumns found in BelongsToMany and MorphToMany eloquent classes.

I would be interested in writing up a pull request for this if I have not missed a way of loading pivot attributes from within the custom pivot model class and it seems like a valuable feature.

[macropay-solutions]

Hi.

You can use the logic from here https://github.com/macropay-solutions/laravel-crud-wizard-free/blob/7d1e1d24e257f51b4249a7ca4d0e09f097bd0d7f/src/Models/BaseModel.php#L66 without adding new code to laravel:

->withPivot((new PivotClass())->getColumns());