Abandoned attempt at a nice Go package for PayPal's NVP API. That API is too much of an abomination to proceed

README.md

nvelop

PayPal Name-Value Pair API for Go.

Supports:

• Express Checkout
• Refunding transactions
• Permissions service

client.go

package nvelop // import "github.com/mndrix/nvelop"
import (
	"net/http"
	"net/url"
)

type Client struct {
	// TODO

	HttpClient *http.Client
}

func (client *Client) Request(method string, version int, endpoint *url.URL) error {
	// TODO method to perform a generic request
	// TODO should take an authenticator to add auth details to the request
	// TODO should
	return nil
}

client_test.go

package nvelop // import "github.com/mndrix/nvelop"
import "testing"

func TestFoo(t *testing.T) {
	// TODO simple test for GetPalDetails call
}

endpoint.go

package nvelop // import "github.com/mndrix/nvelop"

type Endpoint string

type Service int

const (
	Merchant         Service = iota
	Payflow          Service = iota
	AdaptiveAccounts Service = iota
	AdaptivePayments Service = iota
	Invoicing        Service = iota
	Permissions      Service = iota
)

// TODO represent the information at https://developer.paypal.com/docs/classic/api/endpoints/
// TODO as Go data types, etc.

get-balance.go

package nvelop // import "github.com/mndrix/nvelop"

import "log"

type GetBalanceRequest struct {
	ReturnAllCurrencies bool `nvelop:"RETURNALLCURRENCIES,v51"`
}

func (*GetBalanceRequest) Service() Service { return Merchant }
func (*GetBalanceRequest) Method() string   { return "GetBalance" }

// sample response text:
// L_AMT0=0%2e00&L_CURRENCYCODE0=USD&TIMESTAMP=2016%2d10%2d28T15%3a48%3a19Z&CORRELATIONID=665dcabc3a98f&ACK=Success&VERSION=204%2e0&BUILD=24616352
type GetBalanceResponse struct {
	Response

	// TODO probably should be `Amounts []GetBalanceAmount` with
	// TODO type GetBalanceAmount struct { Amount L_AMT; Currency L_CURRENCYCODE }
	// TODO the trailing 0 is the index into Amounts but name is index into GetBalanceAmount struct
	// TODO position of the "trailing 0" needs to be configurable since Express Checkout puts it in the middle
	// TODO needs to support something like "L_FOO_{n}_BAR{m}" for nested arrays
	Amounts    []int    `nvelop:"L_AMT,money"`
	Currencies []string `nvelop:"L_CURRENCYCODE"`
}

// BalanceFor returns the balance (in pennies) for the given currency. Returns
// false if balance information for the given currency is not available.
func (self *GetBalanceResponse) BalanceFor(currency string) (int, bool) {
	if len(self.Amounts) != len(self.Currencies) {
		log.Panicf("GetBalanceResponse slices have different lengths: %d vs %d", len(self.Amounts), len(self.Currencies))
	}

	for i, c := range self.Currencies {
		if c == currency {
			return self.Amounts[i], true
		}
	}

	return 0, false
}

get-pal-details.go

package nvelop // import "github.com/mndrix/nvelop"

type GetPalDetailsRequest struct {
}

func (*GetPalDetailsRequest) Service() Service { return Merchant }
func (*GetPalDetailsRequest) Method() string   { return "GetPalDetails" }

// sample response text:
// PAL=WH8M3P3T9FDVL&LOCALE=en_US&TIMESTAMP=2016%2d10%2d28T15%3a50%3a48Z&CORRELATIONID=3db311449346f&ACK=Success&VERSION=204%2e0&BUILD=24616352
type GetPalDetailsResponse struct {
	Response

	Pal    string `nvelop:"PAL"`
	Locale string `nvelop:"LOCALE"`
}

response.go

package nvelop // import "github.com/mndrix/nvelop"

import "time"

type Response struct {
	Ack           string    `nvelop:"ACK"`
	CorrelationId string    `nvelop:"CORRELATIONID"`
	Time          time.Time `nvelop:"TIMESTAMP"`
	Version       string    `nvelop:"VERSION"`
	Build         int       `nvelop:"BUILD"`

	Errors []Error
}

type Error struct {
	Code         int    `nvelop:"L_ERRORCODE"`
	ShortMessage string `nvelop:"L_SHORTMESSAGE"`
	LongMessage  string `nvelop:"L_LONGMESSAGE"`
	Severity     string `nvelop:"L_SEVERITYCODE"`
	ParamId      string `nvelop:"L_ERRORPARAMID"`
	ParamValue   string `nvelop:"L_ERRORPARAMVALUE"`
}

set-express-checkout.go

// See
// https://developer.paypal.com/docs/classic/api/merchant/SetExpressCheckout_API_Operation_NVP/
// for full API documentation.
package nvelop // import "github.com/mndrix/nvelop"

import "net/url"

type Channel string
type CheckoutFlow string
type Page string
type PaymentReason string
type PaymentMethod string
type PaymentAction string

const (
	Sole CheckoutFlow = "Sole"
	Mark CheckoutFlow = "Mark"

	Billing Page = "Billing"
	Login   Page = "Login"

	Merchant Channel = "Merchant"
	EbayItem Channel = "eBayItem"

	None   PaymentReason = "None"
	Refund PaymentReason = "Refund"

	InstantOnly PaymentMethod = "InstantPaymentOnly"

	Sale          PaymentAction = "Sale"
	Authorization PaymentAction = "Authorization"
	Order         PaymentAction = "Order"
)

type SetExpressCheckoutRequest struct {
	Token string `nvelop:"TOKEN"`

	PaymentRequests         []*PaymentRequest `nvelop:"PAYMENTREQUEST_"`
	MaximumAmount           int               `nvelop:"MAXAMT,money"`
	ReturnUrl               *url.URL          `nvelop:"RETURNURL"`
	CancelUrl               *url.URL          `nvelop:"CANCELURL"`
	CallbackUrl             *url.URL          `nvelop:"CALLBACK"`
	CallbackTimeout         int               `nvelop:"CALLBACKTIMEOUT"`
	CallbackVersion         string            `nvelop:"CALLBACKVERSION"`
	RequireConfirmedAddress bool              `nvelop:"REQCONFIRMSHIPPING"` // TODO need way to omit field entirely
	NoShipping              int               `nvelop:"NOSHIPPING"`
	AllowNote               bool              `nvelop:"ALLOWNOTE"`
	AddressOverride         bool              `nvelop:"ADDROVERRIDE"`
	Locale                  string            `nvelop:"LOCALECODE"`
	PageStyle               string            `nvelop:"PAGESTYLE"`
	HeaderImage             *url.URL          `nvelop:"HDRIMG"`
	PayflowColor            string            `nvelop:"PAYFLOWCOLOR"`
	CartBorderColor         string            `nvelop:"CARTBORDERCOLOR"`
	LogoImage               *url.URL          `nvelop:"LOGOIMG"`
	BuyerEmail              string            `nvelop:"EMAIL"`
	SolutionType            CheckoutFlow      `nvelop:"SOLUTIONTYPE"`
	LandingPage             Page              `nvelop:"LANDINGPAGE"`
	ChannelType             Channel           `nvelop:"CHANNELTYPE"`

	GiropaySuccessUrl *url.URL `nvelop:"GIROPAYSUCCESSURL"`
	GiropayCancelUrl  *url.URL `nvelop:"GIROPAYCANCELURL"`
	BankTransferUrl   *url.URL `nvelop:"BANKTXNPENDINGURL"`

	BrandName             string `nvelop:"BRANDNAME"`
	CustomerServiceNumber string `nvelop:"CUSTOMERSERVICENUMBER"`
	Note                  string `nvelop:"NOTETOBUYER"`
}

func (*SetExpressCheckoutRequest) Service() Service { return Merchant }
func (*SetExpressCheckoutRequest) Method() string   { return "SetExpressCheckout" }

type SetExpressCheckoutResponse struct {
	Response
}

type PaymentRequest struct {
	Id       string        `nvelop:"_PAYMENTREQUESTID"`
	Amount   int           `nvelop:"_AMT,money"`
	Currency string        `nvelop;"_CURRENCYCODE"`
	Reason   PaymentReason `nvelop:"_PAYMENTREASON"`
	ShipTo   Address       `nvelop:"_SHIPTO"`

	ItemAmount       int      `nvelop:"_ITEMAMT,money"`
	ShippingAmount   int      `nvelop:"_SHIPPINGAMT,money"`
	InsuranceAmount  int      `nvelop:"_INSURANCEAMT,money"`
	ShippingDiscount int      `nvelop:"_SHIPDISCAMT,money"`      // negative number
	InsuranceOffered bool     `nvelop:"_INSURANCEOPTIONOFFERED"` // TODO boolean renders as "true" or "false" for this field
	HandlingAmount   int      `nvelop:"_HANDLINGAMT,money"`
	TaxAmount        int      `nvelop:"_TAXAMT,money"`
	Description      string   `nvelop:"_DESC"`
	Custom           string   `nvelop:"_CUSTOM"`
	InvoiceNumber    string   `nvelop:"_INVNUM"`
	NotifyUrl        *url.URL `nvelop:"_NOTIFYURL"`
	MultiShipping    bool     `nvelop:"_MULTISHIPPING"`
	Note             string   `nvelop:"_NOTETEXT"`

	// error in the docs? field is only part of DoExpressCheckout response
	//TransactionId string `nvelop:"_TRANSACTIONID"`

	AllowedPayment PaymentMethod `nvelop:"_ALLOWEDPAYMENTMETHOD"`
	PaymentAction  PaymentAction `nvelop:"_PAYMENTACTION"`
	Bucket         int           `nvelop:"_BUCKETCATEGORYTYPE"`
	LocationType   int           `nvelop:"_LOCATION_TYPE,v115"`
	LocationId     string        `nvelop:"_LOCATION_ID,v115"`

	// TODO this field needs L_PAYMENTREQUEST_n prefix instead of PAYMENTREQUEST_n
	Items []PaymentRequestItem
}

type PaymentRequestItem struct {
	Name        string
	Description string
	Amount      int // money
	Number      string
	Quantity    int
	TaxAmount   int // money
	Weight      int
	Length      int
	Width       int
	Height      int
	WeightUnit  string
	LengthUnit  string
	WidthUnit   string
	HeighUnit   string
}

type Address struct {
	Name    string `nvelop:"NAME"`
	Street  string `nvelop:"STREET"`
	Street2 string `nvelop:"STREET2"`
	City    string `nvelop:"CITY"`
	State   string `nvelop:"STATE"`
	Zip     string `nvelop:"ZIP"`
	Country string `nvelop:"COUNTRYCODE"`
	Phone   string `nvelop:"PHONENUM"`
}