Questions regarding implementing PlanContract

[mrjandejong]

I have some questions regrading implementing the Laravel\Cashier\Plan\Contracts\Plan:

• Under which circumstances does cashier-mollie use the firstPaymentAmount()?
  Even though I have set the first_payment_amount to 1 cent it still starts with the full month price. Fortunately this is what I want to happen anyway, but I would like to know why it actually doesn't use the first_payment_amount
• How to implement orderItemPreprocessors()?
  I current just return new OrderItemPreprocessorCollection;. But I would just like to use the defaults as described in the config files... Will it still use ProcessCoupons etc. like this, or nah?

This is my model file sofar:

<?php

namespace App\Models;

use Money\Money;
use Money\Currency;
use Illuminate\Database\Eloquent\Model;
use Laravel\Cashier\Plan\Contracts\Plan as PlanContract;
use Laravel\Cashier\Order\OrderItemPreprocessorCollection;

class Plan extends Model implements PlanContract
{
    protected $fillable = [
        'name', 'amount', 'interval', 'description', 'currency','first_payment_description','first_payment_amount'
    ];
    
    /**
     * @return \Money\Money
     */
    public function amount() {
        $currency = new Currency($this->attributes['currency']);
        
        return new Money($this->attributes['amount'], $currency);
    }

    /**
     * @param \Money\Money $amount
     * @return Plan
     */
    public function setAmount(Money $amount)
    {
        $this->attributes['currency'] = $amount->getCurrency();
        $this->attributes['amount'] = $amount->getAmount();
        
        return $this;
    }

    /**
     * @return string
     */
    public function description()
    {
        return $this->attributes['description'];
    }

    /**
     * @return string
     */
    public function interval()
    {
        return $this->attributes['interval'];
    }

    /**
     * @return string
     */
    public function name()
    {
        return $this->attributes['name'];
    }

    /**
     * The amount the customer is charged for a mandate payment.
     *
     * @return \Money\Money
     */
    public function firstPaymentAmount()
    {
        $currency = new Currency($this->attributes['first_payment_currency']);
        
        return new Money($this->attributes['first_payment_amount'], $currency);
    }

    /**
     * @param \Money\Money $firstPaymentAmount
     * @return Plan
     */
    public function setFirstPaymentAmount(Money $firstPaymentAmount)
    {
        $this->attributes['first_payment_currency'] = $firstPaymentAmount->getCurrency();
        $this->attributes['first_payment_amount'] = $firstPaymentAmount->getAmount();
        
        return $this;
    }

    /**
     * @return string
     */
    public function firstPaymentMethod()
    {
        return config('cashier.first_payment.method');
    }

    /**
     * @param string $firstPaymentMethod
     * @return Plan
     */
    public function setFirstPaymentMethod(?string $firstPaymentMethod)
    {
        throw new Exception('Table is lacking column to persist this value');
    }

    /**
     * The description for the mandate payment order item.
     *
     * @return string
     */
    public function firstPaymentDescription()
    {
        return $this->attributes['first_payment_description'];
    }

    /**
     * @param string $firstPaymentDescription
     * @return Plan
     */
    public function setFirstPaymentDescription(string $firstPaymentDescription)
    {
        $this->attributes['first_payment_description'] = $firstPaymentDescription;
        
        return $this;
    }

    /**
     * @return string
     */
    public function firstPaymentRedirectUrl()
    {
        return config('cashier.first_payment.redirect_url');
    }

    /**
     * @param string $redirectUrl
     * @return Plan
     */
    public function setFirstPaymentRedirectUrl(string $redirectUrl)
    {
        throw new Exception('Table is lacking column to persist this value');
    }

    /**
     * @return string
     */
    public function firstPaymentWebhookUrl()
    {
        return config('cashier.first_payment.webhook_url');
    }

    /**
     * @param string $webhookUrl
     * @return Plan
     */
    public function setFirstPaymentWebhookUrl(string $webhookUrl)
    {
        throw new Exception('Table is lacking column to persist this value');
    }
    
    /**
     * @return \Laravel\Cashier\Order\OrderItemPreprocessorCollection
     */
    public function orderItemPreprocessors()
    {
        return new OrderItemPreprocessorCollection;
    }

    /**
     * @param \Laravel\Cashier\Order\OrderItemPreprocessorCollection $preprocessors
     * @return \Laravel\Cashier\Plan\Contracts\Plan
     */
    public function setOrderItemPreprocessors(OrderItemPreprocessorCollection $preprocessors)
    {
        $this->orderItemPreprocessors = $preprocessors;

        return $this;
    }
}

[sandervanhooft]

The first payment amount is used when the first payment (mandate payment) is not a normal subscription payment, i.e. when starting with a trial.

[sandervanhooft]

If you want to use the default preprocessors you should return these from the orderItemPreprocessors method.