Perl Requires Chilkat v11.7.0+

Why a PDF Text Replacement Is Refused: the Font Rule

See more PDF Text Replacement Examples

A PDF stores glyphs drawn with particular fonts, so new text can only be drawn when the original font can draw it. This example shows the two common refusals. A font embedded as a subset carries only the glyphs the document used: a value made of other characters is refused with the reason missingGlyph, and the report names the font and the characters it lacks. A font that is neither one of the standard 14 nor embedded (here Verdana) is refused with nonStandardUnembeddedFont, because Chilkat cannot know what a viewer will draw for it. A non-embedded Arial, Times New Roman or Courier New is treated as the standard font every viewer substitutes for it. 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 quote_subset_font.pdf
# and letter_verdana.pdf

# 1. An embedded subset font: only the glyphs the document uses are in the PDF.
my $pdf = Chilkat2::Pdf->new;
my $success = $pdf->LoadFile('qa_data/pdf/quote_subset_font.pdf');
if (!$success) {
    print $pdf->LastErrorText, "\n";
    exit;
}

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

# The regular face's subset carries the characters of the quotation's text, among them the digits of
# "58341".  A new number made of those digits can be drawn...
$json->UpdateString('labels[0].label', 'Quote #:');
$json->UpdateString('labels[0].value', '58314');
$success = $pdf->TextReplace('check', $json, $jsonOut);
if (!$success) {
    print $pdf->LastErrorText, "\n";
    exit;
}

print '58314: ok = ', ($jsonOut->BoolOf('ok') ? 1 : 0), "\n";

# ...but "Q" and "-" are not in the subset (nothing in the quotation's regular text uses them).
$json->UpdateString('labels[0].value', 'Q-58341');
$success = $pdf->TextReplace('check', $json, $jsonOut);
if (!$success) {
    print $pdf->LastErrorText, "\n";
    exit;
}

print 'Q-58341: ok = ', ($jsonOut->BoolOf('ok') ? 1 : 0), "\n";
if (!$jsonOut->BoolOf('ok')) {
    # The problem names the font and the characters it cannot draw.
    print '    reason: ', $jsonOut->StringOf('problems[0].reason'), "\n";
    print '    font: ', $jsonOut->StringOf('problems[0].font'), "\n";
    print '    missing: ', $jsonOut->StringOf('problems[0].chars'), "\n";
}

# "apply" with a problem returns false and changes nothing.
$success = $pdf->TextReplace('apply', $json, $jsonOut);
print 'apply returned ', ($success ? 1 : 0), ', applied = ', ($jsonOut->BoolOf('applied') ? 1 : 0), "\n";

# 2. A font that is not embedded and not one of the standard 14.
my $pdf2 = Chilkat2::Pdf->new;
$success = $pdf2->LoadFile('qa_data/pdf/letter_verdana.pdf');
if (!$success) {
    print $pdf2->LastErrorText, "\n";
    exit;
}

my $json2 = Chilkat2::JsonObject->new;
$json2->UpdateString('labels[0].label', 'Account Number:');
$json2->UpdateString('labels[0].value', '0000099999');
$success = $pdf2->TextReplace('check', $json2, $jsonOut);
if (!$success) {
    print $pdf2->LastErrorText, "\n";
    exit;
}

print 'Verdana, not embedded: ok = ', ($jsonOut->BoolOf('ok') ? 1 : 0), ', reason: ', $jsonOut->StringOf('problems[0].reason'), ', font: ', $jsonOut->StringOf('problems[0].font'), "\n";

# Sample output:

# 58314: ok = true
# Q-58341: ok = false
#     reason: missingGlyph
#     font: AAAAAA+DejaVuSans
#     missing: Q-
# apply returned false, applied = false
# Verdana, not embedded: ok = false, reason: nonStandardUnembeddedFont, font: Verdana