Forms · phppdf

Reading form fields

use PhpPdf\Reader\PdfDocumentReader;
use PhpPdf\Reader\PdfAcroFormReader;

$doc    = PdfDocumentReader::open('/path/to/form.pdf');
$reader = new PdfAcroFormReader($doc);

// All fields as a flat list
foreach ($reader->getFields() as $field) {
    echo $field->fullName . "\n";   // e.g. "address.city"
    echo $field->type->name . "\n"; // Text, Button, Choice
    var_dump($field->value);        // string, bool, or null
    print_r($field->options);       // list<string> for Choice fields
}

// Look up by full name
$fieldMap = $reader->getFieldsByName();
$city = $fieldMap['address.city'] ?? null;

PdfFormField properties

Property	Type	Description
`objectNumber`	`int`	PDF object number
`generationNumber`	`int`	PDF generation number
`name`	`string`	Partial field name (/T)
`fullName`	`string`	Dot-separated full name
`type`	`PdfFormFieldType`	`Text`, `Button`, `Choice`
`value`	`string\|bool\|null`	Current value
`options`	`list<string>`	Available choices (Choice fields)
`readOnly`	`bool`	Whether the field is read-only
`multiLine`	`bool`	Whether a Text field is multi-line

Hierarchical forms

Form fields are organised in a tree. getFields() returns only leaf fields (fields with a type). Parent nodes (intermediate groups) are traversed automatically.

Filling a form

PdfAcroFormFiller writes an incremental update — it appends changes to the end of the original bytes, leaving the original byte ranges intact (required for digital-signature compatibility).

use PhpPdf\Reader\PdfAcroFormFiller;

$originalBytes = file_get_contents('/path/to/form.pdf');
$filler = new PdfAcroFormFiller($doc, $originalBytes);

$fields = $reader->getFieldsByName();

// Fill a text field
$filler->setText($fields['firstName'], 'Jane');
$filler->setText($fields['email'],     'jane@example.com');

// Fill a multi-line text area
$filler->setText($fields['message'], "Hello,\nThis is my message.");

// Set a checkbox
$filler->setChecked($fields['subscribe'], true);

// Select a combo-box option (must be one of the field's /Opt values)
$filler->setChoice($fields['country'], 'Netherlands');

// Write to file
$filler->save('/path/to/filled.pdf');

// Or get bytes
$bytes = $filler->getBytes();

What fills and what doesn’t

setText() works on Text fields and text areas.
setChecked() works on Button (checkbox) fields.
setChoice() works on Choice (combo box / list box) fields.
Read-only fields are silently ignored.

Appearance streams

The filler sets NeedAppearances = true in the AcroForm dictionary so that PDF viewers regenerate visual appearances on open. This is the widely-compatible approach; it does not embed pre-rendered appearance streams itself.