Dart Requires Chilkat v11.7.0+

What PDF Text Replacement Does Not Change: Metadata, Links, Form Fields

See more PDF Text Replacement Examples

TextReplace changes the page content only. A placeholder that also appears in the document's metadata (the Title, Author, Subject, Keywords, Creator or Producer), in a link's target URL, or in a form field's value is left as it is and reported in "notReplaced" with "where" saying which. The invoice template's title is "Invoice for {{customer}}" and its "View this invoice online" link points at a URL that holds {{customer}}. Dart

import 'package:chilkat/chilkat.dart';

void main() {
  // 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

  final pdf = CkPdf();
  try {
    pdf.loadFile('qa_data/pdf/invoice_template.pdf');
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  final json = CkJsonObject();
  json.updateString('placeholders.customer', 'Acme Corp');
  // (The other placeholders are left as they are for this example.)
  json.updateString('unusedPlaceholders', 'keep');

  final jsonOut = CkJsonObject();
  try {
    pdf.textReplace('apply', json, jsonOut);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  print('In the page content, customer was replaced ${jsonOut.intOf('replacements[0].count')} times.');

  // Where else the placeholder occurs, untouched:
  var i = 0;
  final countI = jsonOut.sizeOfArray('notReplaced');
  while (i < countI) {
    jsonOut.i = i;
    print('not replaced: {{${jsonOut.stringOf('notReplaced[i].field')}}} in ${jsonOut.stringOf('notReplaced[i].where')}');
    i++;
  }

  try {
    pdf.writeFile('qa_output/invoice_customer.pdf');
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  // Sample output:

  // In the page content, customer was replaced 2 times.
  // not replaced: {{customer}} in metadata
  // not replaced: {{customer}} in linkTarget
}