Python 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. Chilkat2-Python

import sys
import chilkat2

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.
pdf = chilkat2.Pdf()
success = pdf.LoadFile("qa_data/pdf/quote_subset_font.pdf")
if (success == False):
    print(pdf.LastErrorText)
    sys.exit()

json = chilkat2.JsonObject()
jsonOut = chilkat2.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):
    print(pdf.LastErrorText)
    sys.exit()

print("58314: ok = " + str(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):
    print(pdf.LastErrorText)
    sys.exit()

print("Q-58341: ok = " + str(jsonOut.BoolOf("ok")))
if (jsonOut.BoolOf("ok") == False):
    # The problem names the font and the characters it cannot draw.
    print("    reason: " + jsonOut.StringOf("problems[0].reason"))
    print("    font: " + jsonOut.StringOf("problems[0].font"))
    print("    missing: " + jsonOut.StringOf("problems[0].chars"))

# "apply" with a problem returns false and changes nothing.
success = pdf.TextReplace("apply",json,jsonOut)
print("apply returned " + str(success) + ", applied = " + str(jsonOut.BoolOf("applied")))

# 2. A font that is not embedded and not one of the standard 14.
pdf2 = chilkat2.Pdf()
success = pdf2.LoadFile("qa_data/pdf/letter_verdana.pdf")
if (success == False):
    print(pdf2.LastErrorText)
    sys.exit()

json2 = chilkat2.JsonObject()
json2.UpdateString("labels[0].label","Account Number:")
json2.UpdateString("labels[0].value","0000099999")
success = pdf2.TextReplace("check",json2,jsonOut)
if (success == False):
    print(pdf2.LastErrorText)
    sys.exit()

print("Verdana, not embedded: ok = " + str(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