Question

I am currently implementing a credit card processing script, most as provided by the merchant gateway. The code calls functions within a class and returns a string based on the response. The end php code I am using (details removed of course) with example information is:

<?php
$gw = new gwapi;
$gw->setLogin("username", "password");
$gw->setBilling("John","Smith","Acme, Inc.","888","Suite 200", "Beverly Hills",
        "CA","77777","US","555-555-5555","555-555-5556","[e-mail]",
        "www.example.com");
//        "CA","90210","US","[e-mail]");
$gw->setOrder("1234","Big Order",1, 2, "PO1234","65.192.14.10");

$r = $gw->doSale("1.00","4111111111111111","1010");
print $gw->responses['responsetext'];

?>

where setlogin allows me to login, setbilling takes the sample consumer information, set order takes the order id and description, dosale takes the amount charged, cc number and exp date.

when all the variables are sent validated then sent off for processing, a string is returned in the following format:

response=1&responsetext=SUCCESS&authcode=123456&transactionid=23456&avsresponse=M&orderid=&type=sale&response_code=100

where:

• response = transaction approved or
  declined
• response text = textual response
• authcode = transaction authorization
  code
• transactionid = payment gateway tran
  id
• avsresponse = avs response code
• orderid = original order id passed in
  tran request
• response_code = numeric mapping of
  processor response

I am trying to solve for the following:

1. How do I take the data which is
   passed back and display it
   appropriately on the page – If the
   transaction failed or AVS code
   doesnt match my liking or something
   is wrong, an error is displayed to
   the consumer; if the transaction
   processed, they are taken to a
   completion page and the transaction
   id is sent in SESSION as output to
   the consumer
2. If the response_code value matches a
   table of values, certain actions are
   taken, i.e. if code =100, take to
   success page, if code = 300 print
   specific error on original page to
   customer, etc.

Answer 1

Use parse_str() with the array argument (never use without) to get an array with key/value pairs out of the string. You can then easily access the separate values and implement your logic.