XFA Specification
Chapter 21, XDP Specification
XDP Reference
792
<xdp xmlns="http://ns.adobe.com/xdp/">
<localeSet
xmlns="http://www.xfa.org/schema/locale-set/2.4/">
…
</localeSet>
…
</xdp>
The localeSet MIME-type is
text/xml
.
The pdf Element (an XDP Packet)
An XDF
pdf
element encloses a PDF packet (MIME-type
application/pdf
). The PDF packet has the
following format:
<pdf xmlns="http://ns.adobe.com/xdp/pdf/">
<document>
<chunk>
...base64 encoded PDF content...
</chunk>
</document>
</pdf>
XML is a text format, and is not designed to host binary content. PDF files are binary and therefore must be
encoded into a text format before they can be enclosed within an XML format such as XDP. The most
common method for encoding binary resources into a text format, and the method used by the PDF
packet, is
base64 encoding
[RFC2045].
chunk element
The chunk element must enclose a single base64 encoded PDF document. PDF content cannot be broken
into smaller chunks; however, the packet may contain processing instructions that explain how to process
the embedded PDF.
href
The PDF packet may contain a reference to an external file, as shown in the following example. The value
of href is a URI to the original copy of the PDF document. The processing application obtains this value
from the XFDF F-key path. The F-key path is relative to the system on which the PDF document was
created.
<pdf
href="pathname/filename.pdf"
xmlns="http://ns.adobe.com/xdp/pdf/"
/pdf>
The signature Element (an XDP Packet)
The signature packet encloses a detached digital signature. Such a signature may be used to establish the
integrity of part or all of the data in the XFA Data DOM and to support signer authentication. This XDP
packet is not used to save digital signatures that are enveloped in the in the dataset.
See “XML Digital
Signatures” on page 409.
<Signature xmlns="http://www.w3.org/2000/09/xmldsig#">