Xbase++ 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. Xbase++

LOCAL nSuccess
LOCAL oPdf
LOCAL oJson
LOCAL oJsonOut
LOCAL oPdf2
LOCAL oJson2

nSuccess := 0

//  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.
oPdf := CreateObject("Chilkat.Pdf")
nSuccess := oPdf:LoadFile("qa_data/pdf/quote_subset_font.pdf")
IF (nSuccess == 0)
    ? oPdf:LastErrorText
    oPdf:destroy()
    RETURN
ENDIF

oJson := CreateObject("Chilkat.JsonObject")
oJsonOut := CreateObject("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...
oJson:UpdateString("labels[0].label", "Quote #:")
oJson:UpdateString("labels[0].value", "58314")
nSuccess := oPdf:TextReplace("check", oJson, oJsonOut)
IF (nSuccess == 0)
    ? oPdf:LastErrorText
    oPdf:destroy()
    oJson:destroy()
    oJsonOut:destroy()
    RETURN
ENDIF

? "58314: ok = " + Str(oJsonOut:BoolOf("ok"))

//  ...but "Q" and "-" are not in the subset (nothing in the quotation's regular text uses them).
oJson:UpdateString("labels[0].value", "Q-58341")
nSuccess := oPdf:TextReplace("check", oJson, oJsonOut)
IF (nSuccess == 0)
    ? oPdf:LastErrorText
    oPdf:destroy()
    oJson:destroy()
    oJsonOut:destroy()
    RETURN
ENDIF

? "Q-58341: ok = " + Str(oJsonOut:BoolOf("ok"))
IF (oJsonOut:BoolOf("ok") == 0)
    //  The problem names the font and the characters it cannot draw.
    ? "    reason: " + oJsonOut:StringOf("problems[0].reason")
    ? "    font: " + oJsonOut:StringOf("problems[0].font")
    ? "    missing: " + oJsonOut:StringOf("problems[0].chars")
ENDIF

//  "apply" with a problem returns false and changes nothing.
nSuccess := oPdf:TextReplace("apply", oJson, oJsonOut)
? "apply returned " + Str(nSuccess) + ", applied = " + Str(oJsonOut:BoolOf("applied"))

//  2. A font that is not embedded and not one of the standard 14.
oPdf2 := CreateObject("Chilkat.Pdf")
nSuccess := oPdf2:LoadFile("qa_data/pdf/letter_verdana.pdf")
IF (nSuccess == 0)
    ? oPdf2:LastErrorText
    oPdf:destroy()
    oJson:destroy()
    oJsonOut:destroy()
    oPdf2:destroy()
    RETURN
ENDIF

oJson2 := CreateObject("Chilkat.JsonObject")
oJson2:UpdateString("labels[0].label", "Account Number:")
oJson2:UpdateString("labels[0].value", "0000099999")
nSuccess := oPdf2:TextReplace("check", oJson2, oJsonOut)
IF (nSuccess == 0)
    ? oPdf2:LastErrorText
    oPdf:destroy()
    oJson:destroy()
    oJsonOut:destroy()
    oPdf2:destroy()
    oJson2:destroy()
    RETURN
ENDIF

? "Verdana, not embedded: ok = " + Str(oJsonOut:BoolOf("ok")) + ", reason: " + oJsonOut:StringOf("problems[0].reason") + ", font: " + oJsonOut: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

oPdf:destroy()
oJson:destroy()
oJsonOut:destroy()
oPdf2:destroy()
oJson2:destroy()