A basic class for filling out PDF forms using PHP and PDFtk Server.

Notice: This class has been created for an educational purpose.

To use the class, first we need to make sure it is loaded before using it either by using an autoloader or simply using the require directive.

Suppose we have the following PDF form:

###Filling Out the Form

<?php
require 'PdfForm.php';

$data = [
    'first_name' => 'John',
    'last_name'  => 'Smith',
    'occupation' => 'Teacher',
    'age'        => '45',
    'gender'     => 'male'
];

$pdf = new PdfForm('form.pdf', $data);

$pdf->flatten()
    ->save('output.pdf')
    ->download();

Data can be fetched from different sources like a database table, a JSON object or just an array as we did in above snippet.

###Creating a FDF File

If we just need to create a FDF file without filling out a form, we can only use makeFdf() method.

<?php
require 'PdfForm.php';

$data = [
    'first_name' => 'John',
    'last_name'  => 'Smith',
    'occupation' => 'Teacher',
    'age'        => '45',
    'gender'     => 'male'
];

$pdf = new PdfForm('form.pdf', $data);

$fdf = $pdf->makeFdf();

The return value of makeFdf() is the path to the generated FDF file in the tmp directory. You can either get the content of the file or save it to a permanent location.

###Extracting PDF Field Information

If we just need to see what fields and field types exist in the form, we can call the fields() method to get the information:

<?php

require 'PdfForm.php';

$fields = new PdfForm('form.pdf')->fields();

echo $fields;

If there's no need to parse the output, we can pass true to the fields() method to get a human readable output:

<?php

require 'PdfForm.php';

$pdf = new PdfForm('pdf-test.pdf')->fields(true);

echo $pdf;