Tcl Requires Chilkat v11.7.0+

Fill a PDF Template: Replace {{placeholders}} with Values

See more PDF Text Replacement Examples

Demonstrates the TextReplace method on an invoice template whose values are written as placeholders such as {{customer}} and {{total}}. The "placeholders" object names each placeholder and the text to put in; every occurrence on the page is replaced, including a placeholder inside a sentence or inside a label such as "Tax ({{taxRate}}):". The text is redrawn with the font the template used, so the result looks like the template, and a value that is right-aligned in the template stays right-aligned. The changes are written by WriteFile. Tcl

load ./chilkat.dll

set 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 invoice_template.pdf

set pdf [new_CkPdf]

set success [CkPdf_LoadFile $pdf "qa_data/pdf/invoice_template.pdf"]
if {$success == 0} then {
    puts [CkPdf_lastErrorText $pdf]
    delete_CkPdf $pdf
    exit
}

#  The template has these placeholders in its page text:
#    {{customer}} (twice: "Bill To:" and the closing sentence), {{date}}, {{po}},
#    two item rows: {{qty1}} {{desc1}} {{price1}} {{amount1}} and {{qty2}} {{desc2}} {{price2}} {{amount2}},
#    {{subtotal}}, "Tax ({{taxRate}}):" with {{tax}}, and {{total}}.
set json [new_CkJsonObject]

CkJsonObject_UpdateString $json "placeholders.customer" "Acme Corp"
CkJsonObject_UpdateString $json "placeholders.date" "2026-10-18"
CkJsonObject_UpdateString $json "placeholders.po" "PO-88213"
CkJsonObject_UpdateString $json "placeholders.qty1" "2"
CkJsonObject_UpdateString $json "placeholders.desc1" "Cordless drill, 18 V"
CkJsonObject_UpdateString $json "placeholders.price1" "$460.00"
CkJsonObject_UpdateString $json "placeholders.amount1" "$920.00"
CkJsonObject_UpdateString $json "placeholders.qty2" "6"
CkJsonObject_UpdateString $json "placeholders.desc2" "Galvanized hinge, 4 inch"
CkJsonObject_UpdateString $json "placeholders.price2" "$12.50"
CkJsonObject_UpdateString $json "placeholders.amount2" "$75.00"
CkJsonObject_UpdateString $json "placeholders.subtotal" "$995.00"
CkJsonObject_UpdateString $json "placeholders.taxRate" "7.35%"
CkJsonObject_UpdateString $json "placeholders.tax" "$73.13"
CkJsonObject_UpdateString $json "placeholders.total" "$1,068.13"

#  "apply" makes every replacement, or none: if any value cannot be drawn with the
#  template's font, the method returns false, the PDF is unchanged, and jsonOut says why.
set jsonOut [new_CkJsonObject]

set success [CkPdf_TextReplace $pdf "apply" $json $jsonOut]
if {$success == 0} then {
    puts "Not applied: [CkJsonObject_emit $jsonOut]"
    if {$success == 0} then {
        puts [CkPdf_lastErrorText $pdf]
        delete_CkPdf $pdf
        delete_CkJsonObject $json
        delete_CkJsonObject $jsonOut
        exit
    }

}

#  One entry per placeholder: the pages it was found on and how many times it was replaced.
set i 0
set count_i [CkJsonObject_SizeOfArray $jsonOut "replacements"]
while {$i < $count_i} {
    CkJsonObject_put_I $jsonOut $i
    puts [CkJsonObject_stringOf $jsonOut {replacements[i].field}]: [CkJsonObject_IntOf $jsonOut {replacements[i].count}] on page(s) [CkJsonObject_stringOf $jsonOut {replacements[i].pages}]
    set i [expr $i + 1]
}

#  The replacements stay in memory until the PDF is written.
set success [CkPdf_WriteFile $pdf "qa_output/invoice_filled.pdf"]
if {$success == 0} then {
    puts [CkPdf_lastErrorText $pdf]
    delete_CkPdf $pdf
    delete_CkJsonObject $json
    delete_CkJsonObject $jsonOut
    exit
}

puts "Wrote qa_output/invoice_filled.pdf"

#  Sample output:

#  customer: 2 on page(s) 1
#  date: 1 on page(s) 1
#  po: 1 on page(s) 1
#  qty1: 1 on page(s) 1
#  desc1: 1 on page(s) 1
#  price1: 1 on page(s) 1
#  amount1: 1 on page(s) 1
#  qty2: 1 on page(s) 1
#  desc2: 1 on page(s) 1
#  price2: 1 on page(s) 1
#  amount2: 1 on page(s) 1
#  subtotal: 1 on page(s) 1
#  taxRate: 1 on page(s) 1
#  tax: 1 on page(s) 1
#  total: 1 on page(s) 1
#  Wrote qa_output/invoice_filled.pdf

delete_CkPdf $pdf
delete_CkJsonObject $json
delete_CkJsonObject $jsonOut