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For an XFA-based document, assembly of multiple documents is permitted only if the base document is a static XFA document and none of the other documents have XFA forms or Acrobat forms. A dynamic XFA document cannot be assembled with any other documents. If any of these conditions are violated, an exception will be thrown.
In addition to assembly, static XFA documents have the following restrictions:
• You can disassemble a static XFA document, but the result documents are not XFA documents.
• Using the PageOverlay or PageUnderlay elements throws an exception.
• Attempting to change the page size or rotation of a document or to transform the page contents throws an exception.
Perhaps this example can work for you:
<PDF result="intermediate_result.pdf" format="XDP">
<PDF source="intermediate_result.pdf" baseDocument="true"/>
This code shows how to assemble a static XFA-based PDF form with a non-interactive document