Go 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. Go

    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 invoice_template.pdf

    pdf := chilkat.NewPdf()
    success = pdf.LoadFile("qa_data/pdf/invoice_template.pdf")
    if success == false {
        fmt.Println(pdf.LastErrorText())
        pdf.DisposePdf()
        return
    }

    //  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}}.
    json := chilkat.NewJsonObject()
    json.UpdateString("placeholders.customer","Acme Corp")
    json.UpdateString("placeholders.date","2026-10-18")
    json.UpdateString("placeholders.po","PO-88213")
    json.UpdateString("placeholders.qty1","2")
    json.UpdateString("placeholders.desc1","Cordless drill, 18 V")
    json.UpdateString("placeholders.price1","$460.00")
    json.UpdateString("placeholders.amount1","$920.00")
    json.UpdateString("placeholders.qty2","6")
    json.UpdateString("placeholders.desc2","Galvanized hinge, 4 inch")
    json.UpdateString("placeholders.price2","$12.50")
    json.UpdateString("placeholders.amount2","$75.00")
    json.UpdateString("placeholders.subtotal","$995.00")
    json.UpdateString("placeholders.taxRate","7.35%")
    json.UpdateString("placeholders.tax","$73.13")
    json.UpdateString("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.
    jsonOut := chilkat.NewJsonObject()
    success = pdf.TextReplace("apply",json,jsonOut)
    if success == false {
        fmt.Println("Not applied: ", *jsonOut.Emit())
        if success == false {
            fmt.Println(pdf.LastErrorText())
            pdf.DisposePdf()
            json.DisposeJsonObject()
            jsonOut.DisposeJsonObject()
            return
        }

    }

    //  One entry per placeholder: the pages it was found on and how many times it was replaced.
    i := 0
    count_i := jsonOut.SizeOfArray("replacements")
    for i < count_i {
        jsonOut.SetI(i)
        fmt.Println(*jsonOut.StringOf("replacements[i].field"), ": ", jsonOut.IntOf("replacements[i].count"), " on page(s) ", *jsonOut.StringOf("replacements[i].pages"))
        i = i + 1
    }

    //  The replacements stay in memory until the PDF is written.
    success = pdf.WriteFile("qa_output/invoice_filled.pdf")
    if success == false {
        fmt.Println(pdf.LastErrorText())
        pdf.DisposePdf()
        json.DisposeJsonObject()
        jsonOut.DisposeJsonObject()
        return
    }

    fmt.Println("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

    pdf.DisposePdf()
    json.DisposeJsonObject()
    jsonOut.DisposeJsonObject()