Visual Basic 6.0 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. Visual Basic 6.0

Dim success As Long
success = 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.
Dim pdf As New ChilkatPdf
success = pdf.LoadFile("qa_data/pdf/quote_subset_font.pdf")
If (success = 0) Then
    Debug.Print pdf.LastErrorText
    Exit Sub
End If

Dim json As New ChilkatJsonObject
Dim jsonOut As New ChilkatJsonObject

'  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...
success = json.UpdateString("labels[0].label","Quote #:")
success = json.UpdateString("labels[0].value","58314")
success = pdf.TextReplace("check",json,jsonOut)
If (success = 0) Then
    Debug.Print pdf.LastErrorText
    Exit Sub
End If

Debug.Print "58314: ok = " & jsonOut.BoolOf("ok")

'  ...but "Q" and "-" are not in the subset (nothing in the quotation's regular text uses them).
success = json.UpdateString("labels[0].value","Q-58341")
success = pdf.TextReplace("check",json,jsonOut)
If (success = 0) Then
    Debug.Print pdf.LastErrorText
    Exit Sub
End If

Debug.Print "Q-58341: ok = " & jsonOut.BoolOf("ok")
If (jsonOut.BoolOf("ok") = 0) Then
    '  The problem names the font and the characters it cannot draw.
    Debug.Print "    reason: " & jsonOut.StringOf("problems[0].reason")
    Debug.Print "    font: " & jsonOut.StringOf("problems[0].font")
    Debug.Print "    missing: " & jsonOut.StringOf("problems[0].chars")
End If

'  "apply" with a problem returns false and changes nothing.
success = pdf.TextReplace("apply",json,jsonOut)
Debug.Print "apply returned " & success & ", applied = " & jsonOut.BoolOf("applied")

'  2. A font that is not embedded and not one of the standard 14.
Dim pdf2 As New ChilkatPdf
success = pdf2.LoadFile("qa_data/pdf/letter_verdana.pdf")
If (success = 0) Then
    Debug.Print pdf2.LastErrorText
    Exit Sub
End If

Dim json2 As New ChilkatJsonObject
success = json2.UpdateString("labels[0].label","Account Number:")
success = json2.UpdateString("labels[0].value","0000099999")
success = pdf2.TextReplace("check",json2,jsonOut)
If (success = 0) Then
    Debug.Print pdf2.LastErrorText
    Exit Sub
End If

Debug.Print "Verdana, not embedded: ok = " & 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