Connecting to PaymentTrust's Secure Transaction Network - WorldPay

7 DEVELOPMENT
Developing for STLink and STN
This section outlines guidelines and sample code for communicating with STLink. Code
fragments are shown for the more common programming environments.
The supplied strings are only examples and do not represent real strings. Any URLs that are
referenced are valid at the point of this document’s creation and may change at any time.
Requests may be submitted in XML. XML responses will be returned. Submitted code will differ
only in that submitted string requests will be in XML format suggested by PaymentTrust Ltd..
All transaction requests must be submitted to STLink and all batch requests to STLink Batch.
Both STLink and STLink Batch accept the HTTP and HTTPS protocols, though it is
recommended that the HTTPS protocol be used to safely transmit the requests via the Internet.
All requests must be submitted using the HTTP POST method. The POST method works by
supplying key/value pairs, where the key and value are split by the “=” symbol and key/value
pairs by the “&” symbol. For instance: key1=some value&key2=some value... In the case of
STLink, there is one key value pair. The key is StringIn and the value is any transaction type
outlined in section 6.1.
Example Q request (Non XML):
StringIn=VersionUsed^1~MerchantId^100000~UserName^Mariah~UserPassword^rr87uy~TransactionType^
Q~IsTest^1~TimeOut^60000~BatchId^938344376~
Example Q request (XML):
StringIn=1100000Mariahrr87uyQ190000938344376
Though STLink Batch accepts POST requests, it is important to note that the StringIn key is not
required and must not be submitted to the STLink Batch for batch requests. If not the batch
request will be rejected for reason of being a malformed XML document.
The “=” and “&” symbols are standard characters used in the HTTP protocol to separate
key/value pairs, there fore it is important that no “=” and “&” symbols be found in the transactions,
although this can be overcome by escaping all characters after the StringIn key by using URL
encoding. URL encoding allows the “=”, “&” and other HTTP characters to be included in the
transaction.
Example:
StringIn=
Because STLink Batch does use the StringIn key, the batch request must not be URL encoded. If
not the batch request will be rejected for reason of being a malformed XML document.
XML has its own encoding rules. For 0ne, the STLink and STLink Batch will support any XML
document that has been encoded in an 8-bit ANSI character set, such as: ISO-8859-1. Second of
all XML has its own share of “special” characters. If any of these characters are to be included
within the data of a specified transaction tag, they to must be escaped. The table below lists
those characters and their escape sequence.
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