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. Perl

use chilkat();

$success = 0;

#  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 = chilkat::CkPdf->new();
$success = $pdf->LoadFile("qa_data/pdf/invoice_template.pdf");
if ($success == 0) {
    print $pdf->lastErrorText() . "\r\n";
    exit;
}

#  Values for every placeholder except {{po}} (the purchase order number, which this customer has none of).
$json = chilkat::CkJsonObject->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");

$jsonOut = chilkat::CkJsonObject->new();

#  The default, "error": the unfilled {{po}} is a problem and nothing would be applied.
$success = $pdf->TextReplace("check",$json,$jsonOut);
if ($success == 0) {
    print $pdf->lastErrorText() . "\r\n";
    exit;
}

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

#  "keep": {{po}} stays on the page, literally.
$json->UpdateString("unusedPlaceholders","keep");
$success = $pdf->TextReplace("check",$json,$jsonOut);
if ($success == 0) {
    print $pdf->lastErrorText() . "\r\n";
    exit;
}

print "keep: ok = " . $jsonOut->BoolOf("ok") . "\r\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 == 0) {
    print $pdf->lastErrorText() . "\r\n";
    exit;
}

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

$success = $pdf->WriteFile("qa_output/invoice_no_po.pdf");
if ($success == 0) {
    print $pdf->lastErrorText() . "\r\n";
    exit;
}

#  Sample output:

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