Swift 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. Swift

func chilkatTest() {
    var success: Bool = 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.
    let pdf = CkoPdf()!
    success = pdf.loadFile(filePath: "qa_data/pdf/quote_subset_font.pdf")
    if success == false {
        print("\(pdf.lastErrorText!)")
        return
    }

    let json = CkoJsonObject()!
    let jsonOut = CkoJsonObject()!

    //  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(jsonPath: "labels[0].label", value: "Quote #:")
    json.updateString(jsonPath: "labels[0].value", value: "58314")
    success = pdf.textReplace(op: "check", jsonIn: json, jsonOut: jsonOut)
    if success == false {
        print("\(pdf.lastErrorText!)")
        return
    }

    print("58314: ok = \(jsonOut.bool(of: "ok"))")

    //  ...but "Q" and "-" are not in the subset (nothing in the quotation's regular text uses them).
    json.updateString(jsonPath: "labels[0].value", value: "Q-58341")
    success = pdf.textReplace(op: "check", jsonIn: json, jsonOut: jsonOut)
    if success == false {
        print("\(pdf.lastErrorText!)")
        return
    }

    print("Q-58341: ok = \(jsonOut.bool(of: "ok"))")
    if jsonOut.bool(of: "ok") == false {
        //  The problem names the font and the characters it cannot draw.
        print("    reason: \(jsonOut.string(of: "problems[0].reason")!)")
        print("    font: \(jsonOut.string(of: "problems[0].font")!)")
        print("    missing: \(jsonOut.string(of: "problems[0].chars")!)")
    }

    //  "apply" with a problem returns false and changes nothing.
    success = pdf.textReplace(op: "apply", jsonIn: json, jsonOut: jsonOut)
    print("apply returned \(success), applied = \(jsonOut.bool(of: "applied"))")

    //  2. A font that is not embedded and not one of the standard 14.
    let pdf2 = CkoPdf()!
    success = pdf2.loadFile(filePath: "qa_data/pdf/letter_verdana.pdf")
    if success == false {
        print("\(pdf2.lastErrorText!)")
        return
    }

    let json2 = CkoJsonObject()!
    json2.updateString(jsonPath: "labels[0].label", value: "Account Number:")
    json2.updateString(jsonPath: "labels[0].value", value: "0000099999")
    success = pdf2.textReplace(op: "check", jsonIn: json2, jsonOut: jsonOut)
    if success == false {
        print("\(pdf2.lastErrorText!)")
        return
    }

    print("Verdana, not embedded: ok = \(jsonOut.bool(of: "ok")), reason: \(jsonOut.string(of: "problems[0].reason")!), font: \(jsonOut.string(of: "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

}