Rust 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. Rust

let mut 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

let pdf = chilkat::Pdf::new();
success = pdf.load_file("qa_data/pdf/invoice_template.pdf").is_ok();
if !success {
    println!("{}", pdf.last_error_text());
    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}}.
let json = chilkat::JsonObject::new();
let _ = json.update_string("placeholders.customer", "Acme Corp");
let _ = json.update_string("placeholders.date", "2026-10-18");
let _ = json.update_string("placeholders.po", "PO-88213");
let _ = json.update_string("placeholders.qty1", "2");
let _ = json.update_string("placeholders.desc1", "Cordless drill, 18 V");
let _ = json.update_string("placeholders.price1", "$460.00");
let _ = json.update_string("placeholders.amount1", "$920.00");
let _ = json.update_string("placeholders.qty2", "6");
let _ = json.update_string("placeholders.desc2", "Galvanized hinge, 4 inch");
let _ = json.update_string("placeholders.price2", "$12.50");
let _ = json.update_string("placeholders.amount2", "$75.00");
let _ = json.update_string("placeholders.subtotal", "$995.00");
let _ = json.update_string("placeholders.taxRate", "7.35%");
let _ = json.update_string("placeholders.tax", "$73.13");
let _ = json.update_string("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.
let json_out = chilkat::JsonObject::new();
success = pdf.text_replace("apply", &json, &json_out).is_ok();
if !success {
    println!("Not applied: {}", json_out.emit().unwrap_or_default());
    if !success {
        println!("{}", pdf.last_error_text());
        return;
    }

}

// One entry per placeholder: the pages it was found on and how many times it was replaced.
let mut i = 0;
let count_i = json_out.size_of_array("replacements");
while i < count_i {
    json_out.set_i(i);
    println!("{}: {} on page(s) {}", json_out.string_of("replacements[i].field").unwrap_or_default(), json_out.int_of("replacements[i].count"), json_out.string_of("replacements[i].pages").unwrap_or_default());
    i = i + 1;
}

// The replacements stay in memory until the PDF is written.
if pdf.write_file("qa_output/invoice_filled.pdf").is_err() {
    println!("{}", pdf.last_error_text());
    return;
}

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