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. C++

#include <CkPdf.h>
#include <CkJsonObject.h>

void ChilkatSample(void)
    {
    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.
    CkPdf pdf;
    success = pdf.LoadFile("qa_data/pdf/quote_subset_font.pdf");
    if (success == false) {
        std::cout << pdf.lastErrorText() << "\r\n";
        return;
    }

    CkJsonObject json;
    CkJsonObject jsonOut;

    //  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) {
        std::cout << pdf.lastErrorText() << "\r\n";
        return;
    }

    std::cout << "58314: ok = " << jsonOut.BoolOf("ok") << "\r\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) {
        std::cout << pdf.lastErrorText() << "\r\n";
        return;
    }

    std::cout << "Q-58341: ok = " << jsonOut.BoolOf("ok") << "\r\n";
    if (jsonOut.BoolOf("ok") == false) {
        //  The problem names the font and the characters it cannot draw.
        std::cout << "    reason: " << jsonOut.stringOf("problems[0].reason") << "\r\n";
        std::cout << "    font: " << jsonOut.stringOf("problems[0].font") << "\r\n";
        std::cout << "    missing: " << jsonOut.stringOf("problems[0].chars") << "\r\n";
    }

    //  "apply" with a problem returns false and changes nothing.
    success = pdf.TextReplace("apply",json,jsonOut);
    std::cout << "apply returned " << success << ", applied = " << jsonOut.BoolOf("applied") << "\r\n";

    //  2. A font that is not embedded and not one of the standard 14.
    CkPdf pdf2;
    success = pdf2.LoadFile("qa_data/pdf/letter_verdana.pdf");
    if (success == false) {
        std::cout << pdf2.lastErrorText() << "\r\n";
        return;
    }

    CkJsonObject json2;
    json2.UpdateString("labels[0].label","Account Number:");
    json2.UpdateString("labels[0].value","0000099999");
    success = pdf2.TextReplace("check",json2,jsonOut);
    if (success == false) {
        std::cout << pdf2.lastErrorText() << "\r\n";
        return;
    }

    std::cout << "Verdana, not embedded: ok = " << jsonOut.BoolOf("ok") << ", reason: " << jsonOut.stringOf("problems[0].reason") << ", font: " << jsonOut.stringOf("problems[0].font") << "\r\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
    }