silverstripe-userdefinedforms-payments

User Defined Forms Conditional Payments Let's you add conditions to calculate amount and require payment using omnipay module

• Install it using composer composer require a2nt/userdefinedforms-payments

• Define Payment configuration app/_config/api-payment.yml

---
Name: 'webapp-api-payment'
---
SilverStripe\Omnipay\Model\Payment:
  allowed_gateways:
    - 'PayPal_Express'

SilverStripe\Omnipay\GatewayInfo:
  PayPal_Express:
    parameters:
      username: ''
      password: ''
      signature: ''
      testMode: true # Make sure to override this to false

• Rebuild the database and flush the cache.

• Define Payment Rules of a specific User Form at the CMS

Stripe Checkout

When the form’s Payment gateway (or site default) is Omnipay\Stripe\CheckoutGateway, checkout is handled with the Stripe PHP SDK directly (\Stripe\Checkout\Session::create()), not via Omnipay’s ServiceFactory. Implementation: A2nt\UserFormsPayments\Service\StripeCheckoutPaymentProcessor.

Versions

Piece	Version / note
Composer package	stripe/stripe-php ^13 or ^14 (see this package’s composer.json)
Stripe API version	Each stripe/stripe-php release pins a dated Stripe API version via Stripe\Util\ApiVersion::CURRENT (e.g. 2023-10-16 in many v13/v14 releases). Your project’s exact value is in vendor/stripe/stripe-php/lib/Util/ApiVersion.php after composer install. Override per request with the Stripe-Version header if you need to (see Stripe’s docs).
Product	Stripe Checkout (hosted Checkout page; mode: payment with line_items built from the submission).

The Composer constraint is "stripe/stripe-php": "^13 || ^14" (either major line satisfies the requirement).

Configure the secret key the same way as Omnipay Stripe: SilverStripe\Omnipay\GatewayInfo parameters for \Omnipay\Stripe\CheckoutGateway (e.g. apiKey), or fall back to the STRIPE_SK_KEY environment variable (see StripeCheckoutPaymentProcessor::getStripeSecretKey()).

Optional gateway settings (same GatewayInfo block for \Omnipay\Stripe\CheckoutGateway):

Key	Effect
allow_promotion_codes	When true, Session::create sets allow_promotion_codes: true so customers see “Add promotion code” on Checkout. Create coupons/promotion codes in the Stripe Dashboard first.