How do I dynamically set default values in nested factory entities

Defining the Factories

First, define your factories with the necessary relationships and default values:

php
namespace Database\Factories;

use App\Models\Account;
use App\Models\BusinessUnit;
use App\Models\PaymentTerm;
use Illuminate\Database\Eloquent\Factories\Factory;

class AccountFactory extends Factory
{
    protected $model = Account::class;

    public function definition()
    {
        return [
            'name' => $this->faker->company,
            'payment_term_id' => null, // Set the default payment term ID to null
        ];
    }

    public function afterMaking(Account $account)
    {
        $account->payment_term_id = $this->getDefaultPaymentTermId($account);
    }

    public function afterCreating(Account $account)
    {
        $account->payment_term_id = $this->getDefaultPaymentTermId($account);
        $account->save();
    }

    protected function getDefaultPaymentTermId(Account $account)
    {
        $businessUnit = BusinessUnit::find($account->business_unit_id);
        return $businessUnit->default_payment_term_id;
    }
}

In this example, we define the `AccountFactory` with a `payment_term_id` field that is initially set to `null`. We then use the `afterMaking` and `afterCreating` callbacks to dynamically set the `payment_term_id` based on the `default_payment_term_id` of the associated `BusinessUnit`.

Using the Factory

You can use the factory to create accounts with dynamically set payment terms:

php
$account = Account::factory()->create([
    'business_unit_id' => $businessUnit->id,
]);

When creating an account, the factory will automatically set the `payment_term_id` based on the `default_payment_term_id` of the associated `BusinessUnit`.

Considerations

- Make sure your database relationships are properly set up and the necessary foreign keys are defined in your migrations.
- The `getDefaultPaymentTermId` method can be customized to fetch the default payment term based on your specific requirements, such as the current user's business unit or any other dynamic criteria.
- You can extend this approach to handle more complex scenarios with nested relationships or multiple levels of default value calculations.

By using the `afterMaking` and `afterCreating` callbacks, you can dynamically set default values in nested factory entities based on the context or relationships of the created models.