.NET Core C# 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. .NET Core C#

bool 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.
Chilkat.Pdf pdf = new Chilkat.Pdf();
success = pdf.LoadFile("qa_data/pdf/quote_subset_font.pdf");
if (success == false) {
    Debug.WriteLine(pdf.LastErrorText);
    return;
}

Chilkat.JsonObject json = new Chilkat.JsonObject();
Chilkat.JsonObject jsonOut = new Chilkat.JsonObject();

//  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) {
    Debug.WriteLine(pdf.LastErrorText);
    return;
}

Debug.WriteLine("58314: ok = " + Convert.ToString(jsonOut.BoolOf("ok")));

//  ...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) {
    Debug.WriteLine(pdf.LastErrorText);
    return;
}

Debug.WriteLine("Q-58341: ok = " + Convert.ToString(jsonOut.BoolOf("ok")));
if (jsonOut.BoolOf("ok") == false) {
    //  The problem names the font and the characters it cannot draw.
    Debug.WriteLine("    reason: " + jsonOut.StringOf("problems[0].reason"));
    Debug.WriteLine("    font: " + jsonOut.StringOf("problems[0].font"));
    Debug.WriteLine("    missing: " + jsonOut.StringOf("problems[0].chars"));
}

//  "apply" with a problem returns false and changes nothing.
success = pdf.TextReplace("apply",json,jsonOut);
Debug.WriteLine("apply returned " + Convert.ToString(success) + ", applied = " + Convert.ToString(jsonOut.BoolOf("applied")));

//  2. A font that is not embedded and not one of the standard 14.
Chilkat.Pdf pdf2 = new Chilkat.Pdf();
success = pdf2.LoadFile("qa_data/pdf/letter_verdana.pdf");
if (success == false) {
    Debug.WriteLine(pdf2.LastErrorText);
    return;
}

Chilkat.JsonObject json2 = new Chilkat.JsonObject();
json2.UpdateString("labels[0].label","Account Number:");
json2.UpdateString("labels[0].value","0000099999");
success = pdf2.TextReplace("check",json2,jsonOut);
if (success == false) {
    Debug.WriteLine(pdf2.LastErrorText);
    return;
}

Debug.WriteLine("Verdana, not embedded: ok = " + Convert.ToString(jsonOut.BoolOf("ok")) + ", reason: " + jsonOut.StringOf("problems[0].reason") + ", font: " + jsonOut.StringOf("problems[0].font"));

//  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