Integration Guide

PayPal Payments Pro Integration Guide April 2012 83
Getting Started With the PayPal Name-Value Pair API
Creating an NVP Request
A
should consistently URL-encode the complete API request; otherwise, you may find that
unanticipated data causes an error.
NOTE: An HTTP form is automatically URL-encoded by most browsers.
For example, consider the following NVP string:
NAME=Robert Moore&COMPANY=R. H. Moore & Associates
It is encoded as follows:
NAME=Robert+Moore&COMPANY=R%2E+H%2E+Moore+%26+Associates
Use the following methods to URL-encode or URL-decode your NVP strings:
Encoding and decoding methods for URLs
List Syntax for Name-Value Pairs
The PayPal API uses a special syntax for NVP fields defined as lists.
The NVP interface to the PayPal API requires a unique name for each field. In the API, lists
are prefixed by L_. To identify an element within the list, use the offset from the beginning of
the list, starting with 0 as the first element. For example, L_DESC0 is the first line of a
description, L_DESC1, is the second line, and so on.
NOTE: Not all lists follow the L_ prefix convention; however, all lists start with 0 as the first
element.
Language Method
ASP.NET Encode System.Web.HttpUtility.UrlEncode(buffer,
Encoding.Default)
Decode System.Web.HttpUtility.UrlDecode(buffer,
Encoding.Default)
Classic ASP Encode Server.URLEncode
Decode No built-in function. Several implementation examples are available on the
Internet.
Java Encode java.net.URLEncoder.encode
Decode java.net.URLDecoder.decode
PHP Encode urlencode()
Decode urldecode()
ColdFusion Encode URLEncodedFormatstring [, charset]
Decode URLDecodeurlEncodedString[, charset])