Export Form Data in ASP.NET Core PDF Viewer
14 Aug 20265 minutes to read
The PDF Viewer allows you to export form field data in multiple formats for easy storage or integration. Supported formats:
- FDF
- XFDF
- JSON
- JavaScript Object (for custom persistence)
Available methods
- exportFormFields(destination?, format) — Exports data to a file in the specified format.
- exportFormFieldsAsObject(format) — Exports data as a JavaScript object for custom handling.
- importFormFields(sourceOrObject, format) — Import data back into the PDF.
How to export
Use exportFormFields() with an optional destination path and the format type.
Export as FDF
The following example exports form field data as FDF.
<button id="exportFdf">Export FDF</button>
<div class="text-center">
<ejs-pdfviewer id="pdfviewer" style="height:640px; width:100%" resourceUrl="https://cdn.syncfusion.com/ej2/31.1.23/dist/ej2-pdfviewer-lib" documentPath="https://cdn.syncfusion.com/content/pdf/form-filling-document.pdf">
</ejs-pdfviewer>
</div>
<script type="text/javascript">
document.addEventListener('DOMContentLoaded', function () {
var pdfviewer = document.getElementById('pdfviewer').ej2_instances[0];
document.getElementById('exportFdf').addEventListener('click', function () {
if (!pdfviewer) { console.warn('PDF Viewer not ready'); return; }
// Destination is optional; if omitted the browser will prompt.
pdfviewer.exportFormFields('FormData', 'Fdf');
});
});
</script>Export as XFDF
The following example exports form field data as XFDF.
<div class="text-center">
<ejs-pdfviewer id="pdfviewer" style="height:640px; width:100%" resourceUrl="https://cdn.syncfusion.com/ej2/31.1.23/dist/ej2-pdfviewer-lib" documentPath="https://cdn.syncfusion.com/content/pdf/form-filling-document.pdf">
</ejs-pdfviewer>
</div>
<button id="exportXfdf">Export XFDF</button>
<script type="text/javascript">
document.addEventListener('DOMContentLoaded', function () {
var pdfviewer = document.getElementById('pdfviewer').ej2_instances[0];
document.getElementById('exportXfdf').addEventListener('click', function () {
if (!pdfviewer) { console.warn('PDF Viewer not ready'); return; }
pdfviewer.exportFormFields('FormData', 'Xfdf');
});
});
</script>Export as JSON
The following example exports form field data as JSON.
<div class="text-center">
<ejs-pdfviewer id="pdfviewer" style="height:640px; width:100%" resourceUrl="https://cdn.syncfusion.com/ej2/31.1.23/dist/ej2-pdfviewer-lib" documentPath="https://cdn.syncfusion.com/content/pdf/form-filling-document.pdf">
</ejs-pdfviewer>
</div>
<button id="exportJson">Export JSON</button>
<script type="text/javascript">
document.addEventListener('DOMContentLoaded', function () {
var pdfviewer = document.getElementById('pdfviewer').ej2_instances[0];
document.getElementById('exportJson').addEventListener('click', function () {
if (!pdfviewer) { console.warn('PDF Viewer not ready'); return; }
pdfviewer.exportFormFields('FormData', 'Json');
});
});
</script>Export as Object
Use exportFormFieldsAsObject() to obtain form data as a JavaScript object for database or API integration. The format parameter is required and accepts Fdf, Xfdf, Xml or Json.
<div class="text-center">
<ejs-pdfviewer id="pdfviewer" style="height:640px; width:100%" resourceUrl="https://cdn.syncfusion.com/ej2/31.1.23/dist/ej2-pdfviewer-lib" documentPath="https://cdn.syncfusion.com/content/pdf/form-filling-document.pdf">
</ejs-pdfviewer>
</div>
<button id="exportObj">Export Object</button>
<script type="text/javascript">
document.addEventListener('DOMContentLoaded', function () {
var pdfviewer = document.getElementById('pdfviewer').ej2_instances[0];
var exportedData;
document.getElementById('exportObj').addEventListener('click', function () {
if (!pdfviewer) { console.warn('PDF Viewer not ready'); return; }
pdfviewer.exportFormFieldsAsObject('Fdf').then(function (data) {
exportedData = data; // Persist or send to server
console.log('Exported object:', exportedData);
});
// Alternatives:
// pdfviewer.exportFormFieldsAsObject('Xfdf').then(...)
// pdfviewer.exportFormFieldsAsObject('Json').then(...)
});
});
</script>Common Use Cases
- Save user-entered data to your server without altering the original PDF.
- Export as JSON for REST API integration.
- Export as FDF/XFDF for compatibility with other PDF tools.
- Export as Object to merge with app state or store securely.
- Automate exports after validation using validateFormFields()