Stripe Charge for Google AppEngine

gistfile1.go

package payment

import (
	"fmt"

	"appengine"
	"appengine/urlfetch"

	 "github.com/stripe/stripe-go"
	 "github.com/stripe/stripe-go/currency"
	 "github.com/stripe/stripe-go/charge"
	 "github.com/stripe/stripe-go/customer"
)

func chargeViaStripe(context appengine.Context, providerKey, customerId, 
	idempotencyKey string, booking *Booking) (string, bool, string, error) {

	// set provider key
	stripe.Key = providerKey

	// Stripe call via Appengine
	s := setStripeChargeClient(context, providerKey)

	// set currency
	curr, err := getBookingCurrency(booking.Currency)
	if err != nil {
		return "", false, "", ErrInvalidCurrency
	}

	description := fmt.Sprintf("Charge for Booking %v", booking.Id)

	args := &stripe.ChargeParams{
		Customer: customerId,
		Amount: uint64(booking.Total * 100),
		Currency: curr,
		Desc: description,
		Email: booking.BookedBy.Email,
	}

	args.Params.IdempotencyKey = idempotencyKey

	// Do not use charge.New(args) since it will use the default http.Client on
	// the Backend. Use you baked Backend new appengine-context-request-activated
	// client: s.New(args)
	ch, err := s.New(args)
	if err != nil {
		context.Debugf("# Stripe Charge error for booking: %v: %v", 
			booking.Id, err)
		return "", false, "", err
	}

	// return
	return ch.ID, ch.Paid, ch.Status, nil
}

// Set the Stripe Backend http.Client to this specific appengine client context.
// On Appengine an http call is tied to the context (urlfetch.Client(context)), 
// so we need to do this initialization for each call since stripe-go lib was 
// primarly build to use always the same http.Client settings. The API URL and
// version is not exposed outside of the stripe-go package, so we need to add it manually.
func setStripeChargeClient(context appengine.Context, key string) *charge.Client {
	c := &charge.Client{}

	var b stripe.Backend
	b = stripe.BackendConfiguration{stripe.APIBackend, "https://api.stripe.com/v1", 
		urlfetch.Client(context)}

	c.Key = key
	c.B = b

	return c
}