C++ 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. C++

#include <CkPdf.h>
#include <CkJsonObject.h>

void ChilkatSample(void)
    {
    bool 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

    CkPdf pdf;
    success = pdf.LoadFile("qa_data/pdf/invoice_template.pdf");
    if (success == false) {
        std::cout << pdf.lastErrorText() << "\r\n";
        return;
    }

    //  Values for every placeholder except {{po}} (the purchase order number, which this customer has none of).
    CkJsonObject json;
    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");

    CkJsonObject jsonOut;

    //  The default, "error": the unfilled {{po}} is a problem and nothing would be applied.
    success = pdf.TextReplace("check",json,jsonOut);
    if (success == false) {
        std::cout << pdf.lastErrorText() << "\r\n";
        return;
    }

    std::cout << "error (default): ok = " << jsonOut.BoolOf("ok") << ", problem: " << jsonOut.stringOf("problems[0].field") << " " << jsonOut.stringOf("problems[0].reason") << "\r\n";

    //  "keep": {{po}} stays on the page, literally.
    json.UpdateString("unusedPlaceholders","keep");
    success = pdf.TextReplace("check",json,jsonOut);
    if (success == false) {
        std::cout << pdf.lastErrorText() << "\r\n";
        return;
    }

    std::cout << "keep: ok = " << jsonOut.BoolOf("ok") << "\r\n";

    //  "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) {
        std::cout << pdf.lastErrorText() << "\r\n";
        return;
    }

    std::cout << "blank: applied = " << jsonOut.BoolOf("applied") << "\r\n";

    success = pdf.WriteFile("qa_output/invoice_no_po.pdf");
    if (success == false) {
        std::cout << pdf.lastErrorText() << "\r\n";
        return;
    }

    //  Sample output:

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