Perl 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. Chilkat2 Perl

use strict;
use warnings;
use Chilkat2;

# 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

my $pdf = Chilkat2::Pdf->new;
my $success = $pdf->LoadFile('qa_data/pdf/invoice_template.pdf');
if (!$success) {
    print $pdf->LastErrorText, "\n";
    exit;
}

# Values for every placeholder except {{po}} (the purchase order number, which this customer has none of).
my $json = Chilkat2::JsonObject->new;
$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');

my $jsonOut = Chilkat2::JsonObject->new;

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

print 'error (default): ok = ', ($jsonOut->BoolOf('ok') ? 1 : 0), ', 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) {
    print $pdf->LastErrorText, "\n";
    exit;
}

print 'keep: ok = ', ($jsonOut->BoolOf('ok') ? 1 : 0), "\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) {
    print $pdf->LastErrorText, "\n";
    exit;
}

print 'blank: applied = ', ($jsonOut->BoolOf('applied') ? 1 : 0), "\n";

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

# Sample output:

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