What are some potential challenges when using FPDM (fpdf) to fill out PDF forms in PHP?

One potential challenge when using FPDM (fpdf) to fill out PDF forms in PHP is that the library may not support all types of form fields, leading to incomplete or incorrect form filling. To solve this, you can manually inspect the PDF form fields using a tool like Adobe Acrobat and then use FPDM's SetField function to fill out the fields programmatically.

require('fpdm/fpdm.php');

// Specify the PDF form file
$pdf = new FPDM('form.pdf');

// Fill out the form fields manually inspected from the PDF file
$pdf->SetField('field1', 'value1');
$pdf->SetField('field2', 'value2');
$pdf->SetField('field3', 'value3');

// Output the filled PDF form
$pdf->Output();