Node.js Requires Chilkat v11.7.0+

PDF Placeholders Without a Value: Error, Blank or Keep

See more PDF Text Replacement Examples

Demonstrates the "unusedPlaceholders" option, which decides what happens to a placeholder found on the page that has no value in "placeholders": "error" (the default) makes it a problem with the reason unusedPlaceholder, so nothing is applied; "blank" replaces it with nothing; "keep" leaves it on the page as it is. Node.js

NODEJS_PRELUDE

function chilkatExample() {

    var 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

    var pdf = new chilkat.Pdf();
    success = pdf.LoadFile("qa_data/pdf/invoice_template.pdf");
    if (success == false) {
        console.log(pdf.LastErrorText);
        return;
    }

    //  Values for every placeholder except {{po}} (the purchase order number, which this customer has none of).
    var json = new chilkat.JsonObject();
    json.UpdateString("placeholders.customer","Acme Corp");
    json.UpdateString("placeholders.date","2026-10-18");
    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");

    var jsonOut = new chilkat.JsonObject();

    //  The default, "error": the unfilled {{po}} is a problem and nothing would be applied.
    success = pdf.TextReplace("check",json,jsonOut);
    if (success == false) {
        console.log(pdf.LastErrorText);
        return;
    }

    console.log("error (default): ok = " + jsonOut.BoolOf("ok") + ", problem: " + jsonOut.StringOf("problems[0].field") + " " + jsonOut.StringOf("problems[0].reason"));

    //  "keep": {{po}} stays on the page, literally.
    json.UpdateString("unusedPlaceholders","keep");
    success = pdf.TextReplace("check",json,jsonOut);
    if (success == false) {
        console.log(pdf.LastErrorText);
        return;
    }

    console.log("keep: ok = " + jsonOut.BoolOf("ok"));

    //  "blank": {{po}} is replaced by nothing, leaving "PO Number:" with an empty value.
    json.UpdateString("unusedPlaceholders","blank");
    success = pdf.TextReplace("apply",json,jsonOut);
    if (success == false) {
        console.log(pdf.LastErrorText);
        return;
    }

    console.log("blank: applied = " + jsonOut.BoolOf("applied"));

    success = pdf.WriteFile("qa_output/invoice_no_po.pdf");
    if (success == false) {
        console.log(pdf.LastErrorText);
        return;
    }

    //  Sample output:

    //  error (default): ok = false, problem: po unusedPlaceholder
    //  keep: ok = true
    //  blank: applied = true

}

chilkatExample();