Some test text!

platform
search
< Windows samples

PDF Form Fill and Form Data Extraction in C++

Sample C++ code for using PDFTron SDK to programmatically merge forms data with the PDF in order to fill forms, or to extract form field data from the PDF. PDFTron SDK has full support for Forms Data Format (FDF). Learn more about our PDF Form Filler SDK.

Step 1: Get your free trial license key, or sign in

Start Trial
Sign in

Step 2: Add the code:

//---------------------------------------------------------------------------------------
// Copyright (c) 2001-2019 by PDFTron Systems Inc. All Rights Reserved.
// Consult legal.txt regarding legal and license information.
//---------------------------------------------------------------------------------------

#include <PDF/PDFNet.h>
#include <PDF/PDFDoc.h>
#include <PDF/Field.h>
#include <FDF/FDFDoc.h>
#include <FDF/FDFField.h>
#include <iostream>

using namespace std;
using namespace pdftron;
using namespace SDF;
using namespace FDF;
using namespace PDF;

//---------------------------------------------------------------------------------------
// PDFNet includes a full support for FDF (Forms Data Format) and capability to merge/extract 
// forms data (FDF) with/from PDF. This sample illustrates basic FDF merge/extract functionality 
// available in PDFNet.
//---------------------------------------------------------------------------------------
int main(int argc, char *argv[])
{
	int ret = 0;
	PDFNet::Initialize();

	// Relative path to the folder containing test files.
	string input_path =  "../../TestFiles/";
	string output_path = "../../TestFiles/Output/";


	// Example 1)
	// Iterate over all form fields in the document. Display all field names.
	try  
	{
		PDFDoc doc((input_path + "form1.pdf").c_str());
		doc.InitSecurityHandler();

		for(FieldIterator itr = doc.GetFieldIterator(); itr.HasNext(); itr.Next()) 
		{
			cout << "Field name: " << itr.Current().GetName() << endl;
			cout << "Field partial name: " << itr.Current().GetPartialName() << endl;

			cout << "Field type: ";
			Field::Type type = itr.Current().GetType();
			switch(type)
			{
			case Field::e_button: cout << "Button" << endl; break;
			case Field::e_text: cout << "Text" << endl; break;
			case Field::e_choice: cout << "Choice" << endl; break;
			case Field::e_signature: cout << "Signature" << endl; break;
			}

			cout << "------------------------------" << endl;
		}

		cout << "Done." << endl;
	}
	catch(Common::Exception& e)
	{
		cout << e << endl;
		ret = 1;
	}
	catch(...)
	{
		cout << "Unknown Exception" << endl;
		ret = 1;
	}


	// Example 2) Import XFDF into FDF, then merge data from FDF into PDF
	try
	{
		// XFDF to FDF
		// form fields
		cout << "Import form field data from XFDF to FDF." << endl;
		
		FDFDoc fdf_doc1(FDFDoc::CreateFromXFDF((input_path + "form1_data.xfdf").c_str()));
		fdf_doc1.Save((output_path + "form1_data.fdf").c_str());

		// annotations
		cout << "Import annotations from XFDF to FDF." << endl;

		FDFDoc fdf_doc2(FDFDoc::CreateFromXFDF((input_path + "form1_annots.xfdf").c_str()));
		fdf_doc2.Save((output_path + "form1_annots.fdf").c_str());

		// FDF to PDF
		// form fields
		cout << "Merge form field data from FDF." << endl;

		PDFDoc doc((input_path + "form1.pdf").c_str());
		doc.InitSecurityHandler();
		doc.FDFMerge(fdf_doc1);
		
		// To use PDFNet form field appearance generation instead of relying on 
		// Acrobat, uncomment the following two lines:
		// doc.RefreshFieldAppearances();
		// doc.GetAcroForm()->Put("NeedAppearances", new Bool(false));

		doc.Save((output_path + "form1_filled.pdf").c_str(), SDFDoc::e_linearized, 0);

		// annotations
		cout << "Merge annotations from FDF." << endl;

		doc.FDFMerge(fdf_doc2);
		doc.Save((output_path + "form1_filled_with_annots.pdf").c_str(), SDFDoc::e_linearized, 0);
		cout << "Done." << endl;
	}
	catch (Common::Exception& e)
	{
		cout << e << endl;
		ret = 1;
	}
	catch (...)
	{
		cout << "Unknown Exception" << endl;
		ret = 1;
	}


	// Example 3) Extract data from PDF to FDF, then export FDF as XFDF
	try  
	{
		// PDF to FDF
		PDFDoc in_doc((output_path + "form1_filled_with_annots.pdf").c_str());
		in_doc.InitSecurityHandler();
		
		// form fields only
		cout << "Extract form fields data to FDF." << endl;

		FDFDoc doc_fields = in_doc.FDFExtract(PDFDoc::e_forms_only);
		doc_fields.SetPDFFileName("../form1_filled_with_annots.pdf");
		doc_fields.Save((output_path + "form1_filled_data.fdf").c_str());

		// annotations only
		cout << "Extract annotations to FDF." << endl;

		FDFDoc doc_annots = in_doc.FDFExtract(PDFDoc::e_annots_only);
		doc_annots.SetPDFFileName("../form1_filled_with_annots.pdf");
		doc_annots.Save((output_path + "form1_filled_annot.fdf").c_str());

		// both form fields and annotations
		cout << "Extract both form fields and annotations to FDF." << endl;

		FDFDoc doc_both = in_doc.FDFExtract(PDFDoc::e_both);
		doc_both.SetPDFFileName("../form1_filled_with_annots.pdf");
		doc_both.Save((output_path + "form1_filled_both.fdf").c_str());

		// FDF to XFDF
		// form fields
		cout << "Export form field data from FDF to XFDF." << endl;

		doc_fields.SaveAsXFDF((output_path + "form1_filled_data.xfdf").c_str());

		// annotations
		cout << "Export annotations from FDF to XFDF." << endl;

		doc_annots.SaveAsXFDF((output_path + "form1_filled_annot.xfdf").c_str());

		// both form fields and annotations
		cout << "Export both form fields and annotations from FDF to XFDF." << endl;

		doc_both.SaveAsXFDF((output_path + "form1_filled_both.xfdf").c_str());

		cout << "Done." << endl;
	}
	catch(Common::Exception& e)
	{
		cout << e << endl;
		ret = 1;
	}
	catch(...)
	{
		cout << "Unknown Exception" << endl;
		ret = 1;
	}

	// Example 4) Merge/Extract XFDF into/from PDF
	try
	{
		// Merge XFDF from string
		PDFDoc in_doc((input_path + "numbered.pdf").c_str());
		in_doc.InitSecurityHandler();

		cout << "Merge XFDF string into PDF." << endl;

		string str = "<?xml version=\"1.0\" encoding=\"UTF-8\" ?><xfdf xmlns=\"http://ns.adobe.com/xfdf\" xml:space=\"preserve\"><square subject=\"Rectangle\" page=\"0\" name=\"cf4d2e58-e9c5-2a58-5b4d-9b4b1a330e45\" title=\"user\" creationdate=\"D:20120827112326-07'00'\" date=\"D:20120827112326-07'00'\" rect=\"227.7814207650273,597.6174863387978,437.07103825136608,705.0491803278688\" color=\"#000000\" interior-color=\"#FFFF00\" flags=\"print\" width=\"1\"><popup flags=\"print,nozoom,norotate\" open=\"no\" page=\"0\" rect=\"0,792,0,792\" /></square></xfdf>";

		FDFDoc fdoc(FDFDoc::CreateFromXFDF(str));
		in_doc.FDFMerge(fdoc);
		in_doc.Save((output_path + "numbered_modified.pdf").c_str(), SDFDoc::e_linearized, 0);
		cout << "Merge complete." << endl;

		// Extract XFDF as string
		cout << "Extract XFDF as a string." << endl;

		FDFDoc fdoc_new = in_doc.FDFExtract(PDFDoc::e_both);
		UString XFDF_str = fdoc_new.SaveAsXFDF();
		cout << "Extracted XFDF: " << endl;
		cout << XFDF_str << endl;
		cout << "Extract complete." << endl;
	}
	catch(Common::Exception& e)
	{
		cout << e << endl;
		ret = 1;
	}
	catch(...)
	{
		cout << "Unknown Exception" << endl;
		ret = 1;
	}

	// Example 5) Read FDF files directly
	try  
	{
		FDFDoc doc((output_path + "form1_filled_data.fdf").c_str());

		for(FDFFieldIterator itr = doc.GetFieldIterator(); itr.HasNext(); itr.Next()) 
		{
			cout << "Field name: " << itr.Current().GetName() << endl;
			cout << "Field partial name: " << itr.Current().GetPartialName() << endl;

			cout << "------------------------------" << endl;
		}

		cout << "Done." << endl;
	}
	catch(Common::Exception& e)
	{
		cout << e << endl;
		ret = 1;
	}
	catch(...)
	{
		cout << "Unknown Exception" << endl;
		ret = 1;
	}

	// Example 6) Direct generation of FDF.
	try  
	{
		FDFDoc doc;
		// Create new fields (i.e. key/value pairs).
		doc.FieldCreate("Company", PDF::Field::e_text, "PDFTron Systems");
		doc.FieldCreate("First Name", PDF::Field::e_text, "John");
		doc.FieldCreate("Last Name", PDF::Field::e_text, "Doe");
		// ...		

		// doc.SetPdfFileName("mydoc.pdf");

		doc.Save((output_path + "sample_output.fdf").c_str());
		cout << "Done. Results saved in sample_output.fdf" << endl;
	}
	catch(Common::Exception& e)
	{
		cout << e << endl;
		ret = 1;
	}
	catch(...)
	{
		cout << "Unknown Exception" << endl;
		ret = 1;
	}

	PDFNet::Terminate();
	return ret;
}