Ruby 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. Ruby

require 'chilkat'

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 quote_subset_font.pdf
#  and letter_verdana.pdf

#  1. An embedded subset font: only the glyphs the document uses are in the PDF.
pdf = Chilkat::CkPdf.new()
success = pdf.LoadFile("qa_data/pdf/quote_subset_font.pdf")
if (success == false)
    print pdf.lastErrorText() + "\n";
    exit
end

json = Chilkat::CkJsonObject.new()
jsonOut = Chilkat::CkJsonObject.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 == false)
    print pdf.lastErrorText() + "\n";
    exit
end

print "58314: ok = " + jsonOut.BoolOf("ok").to_s() + "\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 == false)
    print pdf.lastErrorText() + "\n";
    exit
end

print "Q-58341: ok = " + jsonOut.BoolOf("ok").to_s() + "\n";
if (jsonOut.BoolOf("ok") == false)
    #  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";
end

#  "apply" with a problem returns false and changes nothing.
success = pdf.TextReplace("apply",json,jsonOut)
print "apply returned " + success.to_s() + ", applied = " + jsonOut.BoolOf("applied").to_s() + "\n";

#  2. A font that is not embedded and not one of the standard 14.
pdf2 = Chilkat::CkPdf.new()
success = pdf2.LoadFile("qa_data/pdf/letter_verdana.pdf")
if (success == false)
    print pdf2.lastErrorText() + "\n";
    exit
end

json2 = Chilkat::CkJsonObject.new()
json2.UpdateString("labels[0].label","Account Number:")
json2.UpdateString("labels[0].value","0000099999")
success = pdf2.TextReplace("check",json2,jsonOut)
if (success == false)
    print pdf2.lastErrorText() + "\n";
    exit
end

print "Verdana, not embedded: ok = " + jsonOut.BoolOf("ok").to_s() + ", 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