E-Payment Integrator 2020 .NET Edition

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ExpressCheckout Component

Properties   Methods   Events   Configuration Settings   Errors  

Express Checkout allows customers the option to quickly pay through PayPal.




The ExpressCheckout component allows you to integrate PayPal payments into your application by redirecting customers to the PayPal site. During the ExpressCheckout process, a token is generated which encodes transaction details and is used to identify the transaction on the PayPal network. After fetching a token, the customer must be redirected to PayPal's website to fill out payment information. PayPal will then redirect the customer to the URL specified by the component's ReturnURL property. PayPal will append the token to this URL so that it can be accessed after both redirects are complete. This token should then be used to verify details about the payment and finalize the transaction.

The first step in this process is to use the SetCheckout method to fetch a token from PayPal. If the Ack property indicates that this is successful, you should append the ResponseToken value to PayPal's express checkout URL and redirect the customer there. Redirection is not handled automatically by the component and requires external implementation. After the customer pays on PayPal's site, the customer will be automatically returned to the ReturnURL. If the customer declines to pay, PayPal will redirect to the CancelURL instead. Both of these properties must be set prior to calling SetCheckout. All of the remaining steps in the ExpressCheckout process must then be performed on the page given by ReturnURL.

The following is an example of fetching a token and redirecting to PayPal's site. Note that the PayPal credentials and URL (User, Password, Signature, and URL) are also required before calling SetCheckout.

expresscheckout1.OrderTotal = "88.88";
expresscheckout1.ReturnURL = "http://localhost/example/return/url";
expresscheckout1.CancelURL = "http://localhost/example/cancel/url";
expresscheckout1.PaymentAction =  ExpresscheckoutPaymentActions.aSale;

// Now check for success and redirect the buyer:
if (expresscheckout1.Ack == "Success")
  // Redirect is not a component method and should be implemented externally
  Redirect("https://www.sandbox.paypal.com/cgi-bin/webscr?cmd=_express-checkout&token=" + expresscheckout1.ResponseToken)

The following steps should now take place on the page indicated by ReturnURL.

Next, the PayPal token must be retrieved. PayPal automatically appends the token to the specified ReturnURL, so this value should be parsed and set as the Token property. The PayPal credentials and URL (User, Password, Signature, and URL) should also be set if they have not already been. Next, GetCheckoutDetails should be called so that Payer and Payment properties are automatically populated. The PayerId property is required before finalizing the transaction, but you may also want to check other fields under the Payer and Payment properties to ensure they are correct.

Finally, if all transaction details are correct, the CheckoutPayment method should be called to finalize the payment. If PaymentAction is set to aSale, this will finalize the transaction and transfer funds to your PayPal account. If instead the PaymentAction is set to aAuthorization, you will need to capture the transaction later.

Property List

The following is the full list of the properties of the component with short descriptions. Click on the links for further details.

AckAcknowledgement code received from PayPal.
BuyerEmailBuyer's email address.
CancelURLURL to which the customer is returned if he decides not to pay with PayPal.
ContactPhonePayer's contact telephone number.
FirewallA set of properties related to firewall access.
IdleThe current status of the component.
InvoiceNumberYour own unique invoice or tracking number.
ItemsThis is the collection of items being purchased.
NoteAn informational note about this settlement that will be displayed in the payer's transaction history.
OrderDescriptionDescription of items the customer is purchasing.
OrderTotalThe total cost of the order to the customer.
PasswordPassword for communicating with PayPal.
PayerThe person being billed for the current purchase.
PayerIdUnique encrypted PayPal customer account number.
PaymentThis contains details about the express checkout payment.
PaymentActionHow you want to obtain payment.
ProxyA set of properties related to proxy access.
ResponseTokenThe time-stamped token value.
ReturnURLURL to which the customer's browser is returned after choosing to pay with PayPal.
ShippingTotalTotal shipping costs for this order.
SignatureValue to use with PayPal's Signature Authentication scheme.
SSLAcceptServerCertInstructs the component to unconditionally accept the server certificate that matches the supplied certificate.
SSLCertThe certificate to be used during SSL negotiation.
SSLServerCertThe server certificate for the last established connection.
TaxTotalSum of tax for all items included in this order.
TimeoutA timeout for the component.
TokenThis property is used to reference a specific Express Checkout transaction in the PayPal network.
URLURL all PayPal payment transactions are posted to.
UserUser name for communicating with Paypal.

Method List

The following is the full list of the methods of the component with short descriptions. Click on the links for further details.

AddCustomFieldThis adds a custom name-value pair to be sent with the next request.
CaptureCompletely or partially settles a previously authorized transaction.
CheckoutPaymentEither obtain payment for a final sale, or request authorization for later capture of payment.
ConfigSets or retrieves a configuration setting.
DoEventsProcesses events from the internal message queue.
GetCheckoutDetailsReturns information about the customer, including name and address on file with PayPal.
GetResponseVarIt is not uncommon for there to be additional response variables returned in the response that cannot be directly obtained via the Response properties.
InterruptInterrupt the current method.
ResetClears all properties to their default values.
SetCheckoutCall this method to begin the Express Checkout process and fetch a token from PayPal which will encode transaction details.
VoidTransactionVoids a prior authorization.

Event List

The following is the full list of the events fired by the component with short descriptions. Click on the links for further details.

ErrorInformation about errors during data delivery.
SSLServerAuthenticationFired after the server presents its certificate to the client.
SSLStatusShows the progress of the secure connection.

Configuration Settings

The following is a list of configuration settings for the component with short descriptions. Click on the links for further details.

AuthAccessTokenThe access token returned by the PayPal Permission Service's GetAccessToken operation.
AuthApplicationIdThe Application ID for the application making a request to the PayPal Permissions Service.
AuthAuthHeaderThe PayPal Permissions Service authentication header.
AuthAuthHeaderNameThe name of the authentication header generated with the PayPal Permissions Service.
AuthCallbackURLThe URL where PayPal will post the RequestToken and VerificationCode.
AuthorizationIdThe authorization identification number of the last payment.
AuthorizeOrderPaymentAuthorize an order payment.
AuthorizingAccountAuthorizing Account Email Address for third-party API access.
AuthPasswordAPI Password for the PayPal Permissions Service.
AuthRequestTokenThe request token used to obtain an Access Token and Token Secret from the PayPal Permissions Service.
AuthRequestURLThe URL for the PayPal Permissions Service operation being requested.
AuthScopeScope of permissions to be requested for PayPal Permissions Service.
AuthSignatureAPI Signature for the PayPal Permissions Service.
AuthTokenSecretThe token secret returned by the PayPal Permission Service's GetAccessToken operation.
AuthUsernameAPI Username for the PayPal Permissions Service.
AuthVerificationCodeThe verification code used to obtain an Access Token and Token Secret from the PayPal Permissions Service.
BuildReturns the Build number contained in the response.
ButtonSourceAdditional information for identifying transactions.
CurrencyCodeSets the type of currency in which you are accepting payments.
CustomA free-form field for your own use.
HandlingTotalTotal handling costs for this order.
IsPartialCaptureIndicates if this capture is for the full amount of payment you authorized.
ItemTotalSum of cost of all items in this order.
LocaleCodeLocale of pages displayed by PayPal during Express Checkout.
PaymentProtectionEligibilityIf the PaymentPendingReason is PaymentReview this will return the protection in force for the transaction.
RawRequestReturns the raw request sent to the server.
RawResponseReturns the full response.
ResponseVersionReturns the Version number contained in the response.
ShipToCityPayer's shipping city.
ShipToCountryCodePayer's shipping country code.
ShipToNamePayer's shipping name.
ShipToPayerAddressShipping address same as billing address.
ShipToPhoneNumberPayer's shipping phone number.
ShipToStatePayer's shipping state.
ShipToStreetFirst line of the payer's shipping street address.
ShipToStreet2Second line of the payer's shipping street address.
ShipToZipPayer's shipping postal code.
TransactionIdTransaction Id used for authorizing and capturing order payments.
VersionAllows the user to set the Version number in the request.
AcceptEncodingUsed to tell the server which types of content encodings the client supports.
AllowHTTPCompressionThis property enables HTTP compression for receiving data.
AllowHTTPFallbackWhether HTTP/2 connections are permitted to fallback to HTTP/1.1.
AllowNTLMFallbackWhether to allow fallback from Negotiate to NTLM when authenticating.
AppendWhether to append data to LocalFile.
AuthorizationThe Authorization string to be sent to the server.
BytesTransferredContains the number of bytes transferred in the response data.
ChunkSizeSpecifies the chunk size in bytes when using chunked encoding.
CompressHTTPRequestSet to true to compress the body of a PUT or POST request.
EncodeURLIf set to true the URL will be encoded by the component.
FollowRedirectsDetermines what happens when the server issues a redirect.
GetOn302RedirectIf set to true the component will perform a GET on the new location.
HTTP2HeadersWithoutIndexingHTTP2 headers that should not update the dynamic header table with incremental indexing.
HTTPVersionThe version of HTTP used by the component.
IfModifiedSinceA date determining the maximum age of the desired document.
KeepAliveDetermines whether the HTTP connection is closed after completion of the request.
KerberosSPNThe Service Principal Name for the Kerberos Domain Controller.
LogLevelThe level of detail that is logged.
MaxHeadersInstructs component to save the amount of headers specified that are returned by the server after a Header event has been fired.
MaxHTTPCookiesInstructs component to save the amount of cookies specified that are returned by the server when a SetCookie event is fired.
MaxRedirectAttemptsLimits the number of redirects that are followed in a request.
NegotiatedHTTPVersionThe negotiated HTTP version.
OtherHeadersOther headers as determined by the user (optional).
ProxyAuthorizationThe authorization string to be sent to the proxy server.
ProxyAuthSchemeThe authorization scheme to be used for the proxy.
ProxyPasswordA password if authentication is to be used for the proxy.
ProxyPortPort for the proxy server (default 80).
ProxyServerName or IP address of a proxy server (optional).
ProxyUserA user name if authentication is to be used for the proxy.
SentHeadersThe full set of headers as sent by the client.
StatusLineThe first line of the last response from the server.
TransferredDataThe contents of the last response from the server.
TransferredDataLimitThe maximum number of incoming bytes to be stored by the component.
TransferredHeadersThe full set of headers as received from the server.
TransferredRequestThe full request as sent by the client.
UseChunkedEncodingEnables or Disables HTTP chunked encoding for transfers.
UseIDNsWhether to encode hostnames to internationalized domain names.
UsePlatformDeflateWhether to use the platform implementation to decompress compressed responses.
UsePlatformHTTPClientWhether or not to use the platform HTTP client.
UserAgentInformation about the user agent (browser).
CloseStreamAfterTransferIf true, the component will close the upload or download stream after the transfer.
ConnectionTimeoutSets a separate timeout value for establishing a connection.
FirewallAutoDetectTells the component whether or not to automatically detect and use firewall system settings, if available.
FirewallHostName or IP address of firewall (optional).
FirewallListenerIf true, the component binds to a SOCKS firewall as a server (IPPort only).
FirewallPasswordPassword to be used if authentication is to be used when connecting through the firewall.
FirewallPortThe TCP port for the FirewallHost;.
FirewallTypeDetermines the type of firewall to connect through.
FirewallUserA user name if authentication is to be used connecting through a firewall.
KeepAliveIntervalThe retry interval, in milliseconds, to be used when a TCP keep-alive packet is sent and no response is received.
KeepAliveTimeThe inactivity time in milliseconds before a TCP keep-alive packet is sent.
LingerWhen set to True, connections are terminated gracefully.
LingerTimeTime in seconds to have the connection linger.
LocalHostThe name of the local host through which connections are initiated or accepted.
LocalPortThe port in the local host where the component binds.
MaxLineLengthThe maximum amount of data to accumulate when no EOL is found.
MaxTransferRateThe transfer rate limit in bytes per second.
ProxyExceptionsListA semicolon separated list of hosts and IPs to bypass when using a proxy.
TCPKeepAliveDetermines whether or not the keep alive socket option is enabled.
TcpNoDelayWhether or not to delay when sending packets.
UseIPv6Whether to use IPv6.
UseNTLMv2Whether to use NTLM V2.
CACertFilePathsThe paths to CA certificate files when using Mono on Unix/Linux.
LogSSLPacketsControls whether SSL packets are logged when using the internal security API.
ReuseSSLSessionDetermines if the SSL session is reused.
SSLCACertsA newline separated list of CA certificate to use during SSL client authentication.
SSLCheckCRLWhether to check the Certificate Revocation List for the server certificate.
SSLCipherStrengthThe minimum cipher strength used for bulk encryption.
SSLEnabledCipherSuitesThe cipher suite to be used in an SSL negotiation.
SSLEnabledProtocolsUsed to enable/disable the supported security protocols.
SSLEnableRenegotiationWhether the renegotiation_info SSL extension is supported.
SSLIncludeCertChainWhether the entire certificate chain is included in the SSLServerAuthentication event.
SSLNegotiatedCipherReturns the negotiated ciphersuite.
SSLNegotiatedCipherStrengthReturns the negotiated ciphersuite strength.
SSLNegotiatedCipherSuiteReturns the negotiated ciphersuite.
SSLNegotiatedKeyExchangeReturns the negotiated key exchange algorithm.
SSLNegotiatedKeyExchangeStrengthReturns the negotiated key exchange algorithm strength.
SSLNegotiatedProtocolReturns the negotiated protocol version.
SSLProviderThe name of the security provider to use.
SSLSecurityFlagsFlags that control certificate verification.
SSLServerCACertsA newline separated list of CA certificate to use during SSL server certificate validation.
TLS12SignatureAlgorithmsDefines the allowed TLS 1.2 signature algorithms when UseInternalSecurityAPI is True.
TLS12SupportedGroupsThe supported groups for ECC.
TLS13KeyShareGroupsThe groups for which to pregenerate key shares.
TLS13SignatureAlgorithmsThe allowed certificate signature algorithms.
TLS13SupportedGroupsThe supported groups for (EC)DHE key exchange.
AbsoluteTimeoutDetermines whether timeouts are inactivity timeouts or absolute timeouts.
FirewallDataUsed to send extra data to the firewall.
InBufferSizeThe size in bytes of the incoming queue of the socket.
OutBufferSizeThe size in bytes of the outgoing queue of the socket.
BuildInfoInformation about the product's build.
GUIAvailableTells the component whether or not a message loop is available for processing events.
LicenseInfoInformation about the current license.
UseInternalSecurityAPITells the component whether or not to use the system security libraries or an internal implementation.

Copyright (c) 2022 4D Payments Inc. - All rights reserved.
E-Payment Integrator 2020 .NET Edition - Version 20.0 [Build 8153]