XFA Specification
Chapter 21, XDP Specification
XDP Element Language Syntax
788
compatible manner without loss of information. Because the transformations are lossless, document
workflows can choose arbitrarily when to process documents in a PDF format vs. when to process the
same document in an XML-based format.
Extensibility of XDP and PDF
In addition to providing a format for expressing one or more subassemblies of a PDF document, the XDP
format has the capability to host arbitrary XFA components. This capability to host arbitrary content is also
a feature of PDF. In particular, XDP is an XML-based format with an open content model; the format itself
does not prescribe a closed set of components and can therefore be arbitrarily extended.
XDP Element Language Syntax
This chapter provides a reference for the XDP element. XDP provides a mechanism for packaging units of
XFA components within a surrounding XML container.
Note:
This document describes the XDP format, but does not describe the transformation mechanism
between XDP and PDF nor between XDP any other format.
The XDP format is comprised of a single optional processing instruction (“The
on page 788)
and a single element, known as the
xdp
element (“The
The xfa Processing Instruction
The
xfa
processing instruction may be used to hold meta-data about the XDP document. By convention
this processing instruction is placed near the beginning of the document, ahead of the
xdp
element.
There are two parameters used within the
xfa
processing instruction. They may occur in any order.
generator="name"
The
name
identifies the program and version of that program that generated the document.
APIVersion="version"
The
version
identifies the version of the scripting API for which the contained scripts were
generated. The XFA 2.4 scripting API corresponds to version 2.4.5277.0.
For example, the following fragment comes from an XDP generated by Adobe LiveCycle Designer 7.1.
<?xml version="1.0" encoding="UTF-8" ?>
<?xfa generator="AdobeDesigner_V7.1" APIVersion="2.4.5277.0"?>
<xdp:xdp ...>
...
</xdp:xdp>
XDP Namespace
The
xdp
element must belong to the namespace of
http://ns.adobe.com/xdp/
, which is known as
the XDP namespace.
The
xdp
element should make use of explicitly prefixed namespace notation rather than declaring the
XDP namespace as a default namespace. If the
xdp
element declared the XDP namespace as the default