Fillable format extraction from pdf

Hi Thom Parker, 

I am using browser based script which will run as HTML + JS.  and i am extracting fillable information like filed name, tooltip, tab order, page number and char limit,. Below is the code sample for your reference. 

  <!-- PDF.js -->
  <script src="https://cdn.jsdelivr.net/npm/pdfjs-dist@3.11.174/build/pdf.min.js"></script>
  <!-- SheetJS -->
  <script type="module" src="https://cdn.jsdelivr.net/npm/xlsx@0.18.5/+esm"></script>

  <script type="module">
    import * as XLSX from 'https://cdn.jsdelivr.net/npm/xlsx@0.18.5/+esm';

    const extractFields = async (arrayBuffer) => {
      const fields = [];
      const pdf = await pdfjsLib.getDocument({ data: arrayBuffer }).promise;

      for (let pageNum = 1; pageNum <= pdf.numPages; pageNum++) {
        const page = await pdf.getPage(pageNum);
        const annots = await page.getAnnotations();

        annots.forEach((annot) => {
          if (annot.subtype === 'Widget' && annot.fieldType === 'Tx') {
            fields.push({
              FieldName: annot.fieldName || '',
              Tooltip: annot.alternativeText || '',
              CharacterLimit: annot.maxLen || '',
              Format: getFieldFormat(annot),
              Page: pageNum
            });
          }
        });
      }

      return fields;
    };

    const getFieldFormat = (annot) => {
      const jsAction = annot.actions?.F || annot.additionalActions?.F || '';

      if (typeof jsAction !== 'string') return 'Text';

      if (/AFDate_Format/.test(jsAction)) return 'Date';
      if (/AFNumber_Format/.test(jsAction)) return 'Number';

      const match = jsAction.match(/AFSpecial_Format(\d)/);
      if (match) {
        switch (match[1]) {
          case '0': return 'SSN';
          case '1': return 'Phone Number';
          case '2': return 'ZIP Code';
          case '3': return 'ZIP+4';
          default: return 'Special Format';
        }
      }

      return jsAction ? 'Custom JS Format' : 'Text';
    };