Working with XFA Forms

Dynamic forms are based on an XML specification known as XFA, the “XML Forms Architecture”. It can also convert dynamic XFA form to standard Acroform. The information about the form (as far as PDF is concerned) is very vague – it specifies that fields exist, with properties, and JavaScript events, but does not specify any rendering. The objects of XFA form are drawn at the time loading the document.

Form class provides the capability to deal with static AcroForm and you can get a particular field instance using the Form class’ GetFieldFacade(..) method. However, XFA fields cannot be accessed via the Form.GetFieldFacade(..) method. Instead, use Document.Form.XFA to get/set field values and manipulate XFA field template (set field properties).

The following code snippet also work with Aspose.PDF.Drawing library.

Fill XFA fields

The following code snippet shows you how to fill fields in XFA form.

// For complete examples and data files, visit https://github.com/aspose-pdf/Aspose.PDF-for-.NET
private static void FillXFAFields()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_Forms();

    // Open PDF document
    using (var document = new Aspose.Pdf.Document(dataDir + "FillXFAFields.pdf"))
    {
        // Get names of XFA form fields
        var names = document.Form.XFA.FieldNames;

        // Set field values
        if (names.Length > 0)
        {
            document.Form.XFA[names[0]] = "Field 0";
        }
        if (names.Length > 1)
        {
            document.Form.XFA[names[1]] = "Field 1";
        }

        // Save PDF document
        document.Save(dataDir + "FilledXfa_out.pdf");
    }
}

Convert XFA-to-Acroform

Try online You can check the quality of Aspose.PDF conversion and view the results online at this link: products.aspose.app/pdf/xfa/acroform

Dynamic forms are based on an XML specification known as XFA, the “XML Forms Architecture”. The information about the form (as far as a PDF is concerned) is very vague – it specifies that fields exist, with properties, and JavaScript events, but does not specify any rendering.

Currently, PDF supports two different methods for integrating data and PDF forms:

• AcroForms (also known as Acrobat forms), introduced and included in the PDF 1.2 format specification.
• Adobe XML Forms Architecture (XFA) forms, introduced in the PDF 1.5 format specification as an optional feature (The XFA specification is not included in the PDF specification, it is only referenced.)

We cannot extract or manipulate pages of XFA Forms, because the form content is generated at runtime (during XFA form viewing) within the application trying to display or render the XFA form. Aspose.PDF has a feature that allows developers to convert XFA forms to standard AcroForms.

// For complete examples and data files, visit https://github.com/aspose-pdf/Aspose.PDF-for-.NET
private static void ConvertDynamicXFAToAcroForm()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_Forms();

    // Load dynamic XFA form
    using (var document = new Aspose.Pdf.Document(dataDir + "DynamicXFAToAcroForm.pdf"))
    {
        // Set the form fields type as standard AcroForm
        document.Form.Type = Aspose.Pdf.Forms.FormType.Standard;

        // Save PDF document
        document.Save(dataDir + "StandardAcroForm_out.pdf");
    }
}

Get XFA field properties

To access field properties, first use Document.Form.XFA.Template to access the field template. The following code snippet shows the steps of getting X and Y coordinates of XFA a form field.

// For complete examples and data files, visit https://github.com/aspose-pdf/Aspose.PDF-for-.NET
private static void GetXFAProperties()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_Forms();

    // Open PDF document
    using (var document = new Aspose.Pdf.Document(dataDir + "GetXFAProperties.pdf"))
    {
        // Get names of XFA form fields
        var names = document.Form.XFA.FieldNames;

        // Set field values
        if (names.Length > 0)
        {
            document.Form.XFA[names[0]] = "Field 0";
        }
        if (names.Length > 1)
        {
            document.Form.XFA[names[1]] = "Field 1";
        }

        // Get field position
        if (names.Length > 0)
        {
            Console.WriteLine(document.Form.XFA.GetFieldTemplate(names[0]).Attributes["x"].Value);
            Console.WriteLine(document.Form.XFA.GetFieldTemplate(names[0]).Attributes["y"].Value);
        }

        // Save PDF document
        document.Save(dataDir + "FilledXfa_out.pdf");
    }
}