Go Requires Chilkat v11.7.0+

Replace the Second (or Every) Occurrence of a Label in a PDF

See more PDF Text Replacement Examples

Demonstrates the "occurrence" member of a label entry. By default the first occurrence of a label, in reading order across the selected pages, is replaced; "occurrence" can be a number for the nth, or "all" for every occurrence. The invoice template has "Ref:" twice. 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
    }

    json := chilkat.NewJsonObject()
    jsonOut := chilkat.NewJsonObject()

    //  This template's {{placeholders}} are not being filled here: "keep" leaves them as they are
    //  (the default, "error", would refuse to apply while a placeholder on the page has no value).
    json.UpdateString("unusedPlaceholders","keep")

    //  "Ref:" appears twice on the page (A-1 near the top, A-2 below the totals).
    //  The default replaces the first occurrence only.
    json.UpdateString("labels[0].label","Ref:")
    json.UpdateString("labels[0].value","B-7")
    success = pdf.TextReplace("check",json,jsonOut)
    if success == false {
        fmt.Println(pdf.LastErrorText())
        pdf.DisposePdf()
        json.DisposeJsonObject()
        jsonOut.DisposeJsonObject()
        return
    }

    fmt.Println("default: ", jsonOut.IntOf("replacements[0].count"), " occurrence replaced")

    //  The second occurrence only.
    json.UpdateString("labels[0].occurrence","2")
    success = pdf.TextReplace("check",json,jsonOut)
    if success == false {
        fmt.Println(pdf.LastErrorText())
        pdf.DisposePdf()
        json.DisposeJsonObject()
        jsonOut.DisposeJsonObject()
        return
    }

    fmt.Println("occurrence 2: ", jsonOut.IntOf("replacements[0].count"), " occurrence replaced")

    //  Every occurrence.
    json.UpdateString("labels[0].occurrence","all")
    success = pdf.TextReplace("apply",json,jsonOut)
    if success == false {
        fmt.Println(pdf.LastErrorText())
        pdf.DisposePdf()
        json.DisposeJsonObject()
        jsonOut.DisposeJsonObject()
        return
    }

    fmt.Println("occurrence all: ", jsonOut.IntOf("replacements[0].count"), " occurrences replaced")

    success = pdf.WriteFile("qa_output/invoice_refs.pdf")
    if success == false {
        fmt.Println(pdf.LastErrorText())
        pdf.DisposePdf()
        json.DisposeJsonObject()
        jsonOut.DisposeJsonObject()
        return
    }

    //  Sample output:

    //  default: 1 occurrence replaced
    //  occurrence 2: 1 occurrence replaced
    //  occurrence all: 2 occurrences replaced

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