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Adobe Acrobat SDK
Understanding Plug-ins
Developing Plug-ins and Applications
Storing private data in PDF files 37
Storing private data in PDF files
Plug-ins can store private data in PDF files, although private data must be stored in such a way that the file
can still be drawn by Acrobat. Adobe maintains a registry of private PDF dictionary key names to reduce
the possibility of a plug-in’s key names conflicting with names belonging to other plug-ins. For
information about dictionaries, see
“Working with Cos dictionaries” on page 186
.
Private dictionary keys exist in the following categories:
●
Specific keys that are proposed by third parties but are generally useful. Adobe maintains a registry of
these names.
●
Keys registered by third parties as well as keys whose prefix is registered that are applicable only to a
limited set of users. Adobe maintains a registry of these names and prefixes.
●
Keys that begin with a special prefix reserved by Adobe for private extensions. These keys are intended
for use in files that are never seen by other third parties, since these keys may conflict with keys defined
by others.
Exporting data from PDF document objects
Using the Acrobat core API, you can export data from PDF document objects to XML files. Object data
contain property-value pairs. For example, consider a PDF document object that contains the following
XML elements:
After you export the data from this object into an XML file, the data would appear as shown in the
following diagram.
Node
Name
nodeTag
xyz_Node
nodeNameTag
xyz_NodeName
propTag
xyz_Property
propNameTag
xyz_PropertyName
propValTag
xyz_Value