Dart Requires Chilkat v11.7.0+

Extract a PDF Table with Merged Cells

See more PDF Text Extraction Examples

Demonstrates how merged cells are reported by the "tables" operation: a header cell that spans several columns has colSpan greater than 1, and a row label that spans several rows has rowSpan greater than 1. Also shows the minRows and minColumns options. 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 spans_table.pdf

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

  final json = CkJsonObject();
  final jsonOut = CkJsonObject();

  // Grids smaller than minRows x minColumns are not reported as tables.  The defaults are 2 and 2.
  // Setting them higher skips small boxes that are not really tables.
  json.updateInt('minRows', 3);
  json.updateInt('minColumns', 3);

  try {
    pdf.extractText('tables', json, jsonOut);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  print('Tables found: ${jsonOut.intOf('count')}');
  print('${jsonOut.intOf('tables[0].rows')} rows x ${jsonOut.intOf('tables[0].columns')} columns');

  // A merged cell is reported once, at its top-left position, with its spans.
  // The positions it covers have no cell of their own.
  var rowSpan = 0;
  var colSpan = 0;
  var j = 0;
  final countJ = jsonOut.sizeOfArray('tables[0].cells');
  while (j < countJ) {
    jsonOut.j = j;
    rowSpan = jsonOut.intOf('tables[0].cells[j].rowSpan');
    colSpan = jsonOut.intOf('tables[0].cells[j].colSpan');
    if ((rowSpan > 1) || (colSpan > 1)) {
      print('row ${jsonOut.intOf('tables[0].cells[j].row')}, col ${jsonOut.intOf('tables[0].cells[j].col')}: "${jsonOut.stringOf('tables[0].cells[j].text')}" spans $rowSpan row(s) and $colSpan column(s)');
    }

    j++;
  }

  // Sample output:

  // Tables found: 1
  // 6 rows x 6 columns
  // row 0, col 0: "Area" spans 2 row(s) and 1 column(s)
  // row 0, col 1: "City" spans 2 row(s) and 1 column(s)
  // row 0, col 2: "First Half" spans 1 row(s) and 2 column(s)
  // row 0, col 4: "Second Half" spans 1 row(s) and 2 column(s)
  // row 2, col 0: "East" spans 2 row(s) and 1 column(s)
  // row 4, col 0: "West" spans 2 row(s) and 1 column(s)
}