PHP Extension Requires Chilkat v11.7.0+

PDF Placeholders Without a Value: Error, Blank or Keep

See more PDF Text Replacement Examples

Demonstrates the "unusedPlaceholders" option, which decides what happens to a placeholder found on the page that has no value in "placeholders": "error" (the default) makes it a problem with the reason unusedPlaceholder, so nothing is applied; "blank" replaces it with nothing; "keep" leaves it on the page as it is. PHP Extension

<?php

include("chilkat.php");

$success = false;

//  This example requires the Chilkat API to have been previously unlocked.
//  See Global Unlock Sample for sample code.

//  The PDF used in this example is available at invoice_template.pdf

$pdf = new CkPdf();
$success = $pdf->LoadFile('qa_data/pdf/invoice_template.pdf');
if ($success == false) {
    print $pdf->lastErrorText() . "\n";
    exit;
}

//  Values for every placeholder except {{po}} (the purchase order number, which this customer has none of).
$json = new CkJsonObject();
$json->UpdateString('placeholders.customer','Acme Corp');
$json->UpdateString('placeholders.date','2026-10-18');
$json->UpdateString('placeholders.qty1','2');
$json->UpdateString('placeholders.desc1','Cordless drill, 18 V');
$json->UpdateString('placeholders.price1','$460.00');
$json->UpdateString('placeholders.amount1','$920.00');
$json->UpdateString('placeholders.qty2','6');
$json->UpdateString('placeholders.desc2','Galvanized hinge, 4 inch');
$json->UpdateString('placeholders.price2','$12.50');
$json->UpdateString('placeholders.amount2','$75.00');
$json->UpdateString('placeholders.subtotal','$995.00');
$json->UpdateString('placeholders.taxRate','7.35%');
$json->UpdateString('placeholders.tax','$73.13');
$json->UpdateString('placeholders.total','$1,068.13');

$jsonOut = new CkJsonObject();

//  The default, "error": the unfilled {{po}} is a problem and nothing would be applied.
$success = $pdf->TextReplace('check',$json,$jsonOut);
if ($success == false) {
    print $pdf->lastErrorText() . "\n";
    exit;
}

print 'error (default): ok = ' . $jsonOut->BoolOf('ok') . ', problem: ' . $jsonOut->stringOf('problems[0].field') . ' ' . $jsonOut->stringOf('problems[0].reason') . "\n";

//  "keep": {{po}} stays on the page, literally.
$json->UpdateString('unusedPlaceholders','keep');
$success = $pdf->TextReplace('check',$json,$jsonOut);
if ($success == false) {
    print $pdf->lastErrorText() . "\n";
    exit;
}

print 'keep: ok = ' . $jsonOut->BoolOf('ok') . "\n";

//  "blank": {{po}} is replaced by nothing, leaving "PO Number:" with an empty value.
$json->UpdateString('unusedPlaceholders','blank');
$success = $pdf->TextReplace('apply',$json,$jsonOut);
if ($success == false) {
    print $pdf->lastErrorText() . "\n";
    exit;
}

print 'blank: applied = ' . $jsonOut->BoolOf('applied') . "\n";

$success = $pdf->WriteFile('qa_output/invoice_no_po.pdf');
if ($success == false) {
    print $pdf->lastErrorText() . "\n";
    exit;
}

//  Sample output:

//  error (default): ok = false, problem: po unusedPlaceholder
//  keep: ok = true
//  blank: applied = true

?>