React Native Requires Chilkat v11.7.0+

Replace PDF Text on Selected Pages Only

See more PDF Text Replacement Examples

Demonstrates the "pages" option, which limits the search for placeholders and labels to the given pages: "all" (the default), "first", "last", "odd", "even", or a list such as "1,3,5-9". The two-page order confirmation carries the same "Status:" label on both pages; the status is changed on page 2 only, then on both pages. React Native

import { JsonObject, Pdf } from '@chilkat/react-native'

function chilkatExample() {
  // 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 order_confirmation.pdf

  const pdf = new Pdf();
  try {
    pdf.loadFile('qa_data/pdf/order_confirmation.pdf');
  } catch {
    console.log(pdf.lastErrorText);
    return;
  }

  const json = new JsonObject();
  const jsonOut = new JsonObject();

  // Both pages have "Status:   Pending".  With pages "2", only page 2 is searched.
  json.updateString('pages', '2');
  json.updateString('labels[0].label', 'Status:');
  json.updateString('labels[0].value', 'Shipped');
  try {
    pdf.textReplace('check', json, jsonOut);
  } catch {
    console.log(pdf.lastErrorText);
    return;
  }

  console.log(`pages 2: found on page(s) ${jsonOut.stringOf('replacements[0].pages')}`);

  // With every page searched, the default occurrence ("first") still replaces one -- the first in reading order.
  json.updateString('pages', 'all');
  try {
    pdf.textReplace('check', json, jsonOut);
  } catch {
    console.log(pdf.lastErrorText);
    return;
  }

  console.log(`pages all, first occurrence: found on page(s) ${jsonOut.stringOf('replacements[0].pages')}`);

  // Every occurrence on every page.
  json.updateString('labels[0].occurrence', 'all');
  try {
    pdf.textReplace('apply', json, jsonOut);
  } catch {
    console.log(pdf.lastErrorText);
    return;
  }

  console.log(`pages all, every occurrence: ${jsonOut.intOf('replacements[0].count')} replaced on page(s) ${jsonOut.stringOf('replacements[0].pages')}`);

  try {
    pdf.writeFile('qa_output/order_shipped.pdf');
  } catch {
    console.log(pdf.lastErrorText);
    return;
  }

  // Sample output:

  // pages 2: found on page(s) 2
  // pages all, first occurrence: found on page(s) 1
  // pages all, every occurrence: 2 replaced on page(s) 1,2
}