How can I save only certain pages in SetAPDF-Formfiller - setapdf

Question

I have 3 page PDF form which I fill with a SetaPDF formfiller. The values are taken from a database and based on some values 2nd or 3rd page of the document should be "disabled" in some cases thus not needed in resulting filled document.
How can I make SetaPDF to save only certain pages?
https://manuals.setasign.com/api-reference/setapdf/c/SetaPDF.Core.Document#method_save
does not accept any parameters that define page numbers I want to have in resulting document.
UPD: https://manuals.setasign.com/setapdf-core-manual/pages/#index-5
Delete pages method could help me to get the expected result however I cannot make it work.

Answer 1

A solution with only the SetaPDF-FormFiller component is only possible if you have control about the original document and if you flatten all form fields after filling them!
It will look like following:
<?php
require_once 'library/SetaPDF/Autoload.php';
$writer = new SetaPDF_Core_Writer_File('result.pdf');
$document = SetaPDF_Core_Document::loadByFilename('701201_20220620_175952.pdf', $writer);
$formFiller = new SetaPDF_FormFiller($document);
$fields = $formFiller->getFields();
// ...fill fields
$fields->flatten();
$pages = $document->getCatalog()->getPages();
$pages->deletePage(3);
$pages->deletePage(2);
$document->save(false)->finish();
ATTENTION: Use this method with care! If you e.g. do not flatten the fields, internally all other form fields and their related pages will be kept internally because they are still referenced. The resulting document may look good but its internal structure would be messed.
If you want to keep the form fields and you don't want to care about the internal structure yourself you have to go with the SetaPDF-Merger component. It will keep the internal structure of the PDF document intact and clean:
<?php
require_once 'library/SetaPDF/Autoload.php';
$writer = new SetaPDF_Core_Writer_File('result.pdf');
$document = SetaPDF_Core_Document::loadByFilename('701201_20220620_175952.pdf');
$formFiller = new SetaPDF_FormFiller($document);
$fields = $formFiller->getFields();
//...fill fields
$merger = new SetaPDF_Merger();
$merger->addDocument($document, 1); // only page 1
$merger->merge();
$resDocument = $merger->getDocument();
$resDocument->setWriter($writer);
$resDocument->save()->finish();