How to create interactive form with fixed pages?

[Former Community Member]

Hello,

When I try to open a regular PDF (which doesn't contain an XFA form) using Adobe LiveCycle ES4 Designer it prompts a window (New Form Assistant) and asks me to select how I want to work with the PDF. The options are:

• Create an Interactive Form with Fixed Pages
• Create an Interactive Form with a Flowable Layout

I choose the first one and continue. Then, without doing anything I save the file (using save as). Save as type is 'Acrobat (Static) PDF Form (*.pdf)', and as a matter of fact that's the only option for this scenario. After I save the file, I figured out that, although both files are visually same in the PDF reader, the saved and the original files are different, such that, saved file contains XFA form. In my case XFA form is as follows:

<topmostSubform xmlns:xfa="http://www.xfa.org/schema/xfa-data/1.0/" xfa:dataNode="dataGroup"/>

I have two questions about this.

1. Can I open a regular PDF and add an XFA form to it without corrupting the original PDF content, using the API?
2. If the first one is possible, can I add invisible fields to that PDF, again using the API?

In short, what I want to do is adding a filled XFA form to a regular PDF and I'm asking if it is possible, using the API?