Add File Links and Attachments to Generated PDF Document

EVO PDF Client for .NET Core

EVO HTML to PDF Converter allows you to create relative or absolute file links in PDF and to create file attachments from files or from streams. Optionally you can also add icons to mark the attachments in PDF document. In this demo some of the HTML elements from converted PDF document are marked to become links to files or icons for attachments in the generated PDF document.

The file links are created by adding FileLinkElement objects to a PDF document and the file attachments are created by adding FileAttachmentElement objects to a PDF document when the attachment is marked by an icon in the generated PDF document or by using the DocumentAddFileAttachment(String, String) method when the attachment does not need an icon in the generated PDF document.

Code Sample - Add File Links and Attachments to Generated PDF Document

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using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Http;

using Microsoft.AspNetCore.Hosting;

// Use EVO PDF Namespace
using EvoPdfClient;

namespace EvoHtmlToPdfDemo.Controllers
{
    public class Create_File_Links_and_AtachmentsController : Controller
    {
        private readonly Microsoft.AspNetCore.Hosting.IWebHostEnvironment m_hostingEnvironment;
        public Create_File_Links_and_AtachmentsController(IWebHostEnvironment hostingEnvironment)
        {
            m_hostingEnvironment = hostingEnvironment;
        }

        private void SetCurrentViewData()
        {
            ViewData["ContentRootPath"] = m_hostingEnvironment.ContentRootPath + "/wwwroot";

            HttpRequest request = this.ControllerContext.HttpContext.Request;
            UriBuilder uriBuilder = new UriBuilder();
            uriBuilder.Scheme = request.Scheme;
            uriBuilder.Host = request.Host.Host;
            if (request.Host.Port != null)
                uriBuilder.Port = (int)request.Host.Port;
            uriBuilder.Path = request.PathBase.ToString() + request.Path.ToString();
            uriBuilder.Query = request.QueryString.ToString();

            ViewData["CurrentPageUrl"] = uriBuilder.Uri.AbsoluteUri;
        }

        public ActionResult Index()
        {
            SetCurrentViewData();

            return View();
        }

        [HttpPost]
        public ActionResult ConvertHtmlToPdf(IFormCollection collection)
        {
            // Get the server options
            string serverIP = collection["textBoxServerIP"];
            uint serverPort = uint.Parse(collection["textBoxServerPort"]);
            string servicePassword = collection["textBoxServicePassword"];
            bool useServicePassword = servicePassword.Length > 0;
            bool useTcpService = collection["ServerType"] == "radioButtonUseTcpService";
            string webServiceUrl = collection["textBoxWebServiceUrl"];

            // Create the HTML to PDF converter object
            HtmlToPdfConverter htmlToPdfConverter = null;
            if (useTcpService)
                htmlToPdfConverter = new HtmlToPdfConverter(serverIP, serverPort);
            else
                htmlToPdfConverter = new HtmlToPdfConverter(true, webServiceUrl);

            // Set optional service password
            if (useServicePassword)
                htmlToPdfConverter.ServicePassword = servicePassword;

            // Set license key received after purchase to use the converter in licensed mode
            // Leave it not set to use the converter in demo mode
            htmlToPdfConverter.LicenseKey = "4W9+bn19bn5ue2B+bn1/YH98YHd3d3c=";

            // Set an adddional delay in seconds to wait for JavaScript or AJAX calls after page load completed
            // Set this property to 0 if you don't need to wait for such asynchcronous operations to finish
            htmlToPdfConverter.ConversionDelay = 2;

            string htmlWithLinksAndAttachMarkers = collection["htmlStringTextBox"];
            string baseUrl = collection["baseUrlTextBox"];

            // Convert a HTML string with markers for file links and attachments to a PDF document object
            Document pdfDocument = htmlToPdfConverter.ConvertHtmlToPdfDocumentObject(htmlWithLinksAndAttachMarkers, baseUrl);

            // Display the attachments panel when the PDF document is opened in a PDF viewer
            pdfDocument.ViewerPreferences.PageMode = ViewerPageMode.UseAttachments;

            // Create File Attachments

            // Create an attachment from a file without icon
            string fileAttachmentPath = m_hostingEnvironment.ContentRootPath + "/wwwroot" + "/DemoAppFiles/Input/Attach_Files/Attachment_File.txt";
            pdfDocument.AddFileAttachment(fileAttachmentPath, "Attachment from File");

            // Create an attachment from a stream without icon
            string fileStreamAttachmentPath = m_hostingEnvironment.ContentRootPath + "/wwwroot" + "/DemoAppFiles/Input/Attach_Files/Attachment_Stream.txt";
            byte[] attachmentData = System.IO.File.ReadAllBytes(fileStreamAttachmentPath);
            pdfDocument.AddFileAttachment(attachmentData, "Attachment_Stream.txt", "Attachment from Stream");

            // Create an attachment from file with paperclip icon in PDF
            HtmlElementMapping attachFromFileIconMapping = htmlToPdfConverter.HtmlElementsMappingOptions.HtmlElementsMappingResult.GetElementByMappingId("attach_from_file_icon");
            if (attachFromFileIconMapping != null)
            {
                PdfPage attachFromFilePage = pdfDocument.GetPage(attachFromFileIconMapping.PdfRectangles[0].PageIndex);
                RectangleFloat attachFromFileIconRectangle = attachFromFileIconMapping.PdfRectangles[0].Rectangle;

                string fileAttachmentWithIconPath = m_hostingEnvironment.ContentRootPath + "/wwwroot" + "/DemoAppFiles/Input/Attach_Files/Attachment_File_Icon.txt";

                // Create the attachment from file
                FileAttachmentElement attachFromFileElement = new FileAttachmentElement(attachFromFileIconRectangle, fileAttachmentWithIconPath);
                attachFromFileElement.IconType = FileAttachmentIcon.Paperclip;
                attachFromFileElement.Text = "Attachment from File with Paperclip Icon";
                attachFromFileElement.IconColor = RgbColor.Blue;
                attachFromFilePage.AddElement(attachFromFileElement);
            }

            // Create an attachment from stream with pushpin icon in PDF
            byte[] attachmentDataWithIcon = null;
            HtmlElementMapping attachFromStreamIconMapping = htmlToPdfConverter.HtmlElementsMappingOptions.HtmlElementsMappingResult.GetElementByMappingId("attach_from_stream_icon");
            if (attachFromStreamIconMapping != null)
            {
                PdfPage attachFromStreamPage = pdfDocument.GetPage(attachFromStreamIconMapping.PdfRectangles[0].PageIndex);
                RectangleFloat attachFromStreamIconRectangle = attachFromStreamIconMapping.PdfRectangles[0].Rectangle;

                string fileStreamAttachmentWithIconPath = m_hostingEnvironment.ContentRootPath + "/wwwroot" + "/DemoAppFiles/Input/Attach_Files/Attachment_Stream_Icon.txt";

                attachmentDataWithIcon = System.IO.File.ReadAllBytes(fileStreamAttachmentWithIconPath);

                // Create the attachment from stream
                FileAttachmentElement attachFromStreamElement = new FileAttachmentElement(attachFromStreamIconRectangle, attachmentDataWithIcon, "Attachment_Stream_Icon.txt");
                attachFromStreamElement.IconType = FileAttachmentIcon.PushPin;
                attachFromStreamElement.Text = "Attachment from Stream with Pushpin Icon";
                attachFromStreamElement.IconColor = RgbColor.Green;
                attachFromStreamPage.AddElement(attachFromStreamElement);
            }

            // Save the PDF document in a memory buffer
            byte[] outPdfBuffer = pdfDocument.Save();

            // Send the PDF file to browser
            FileResult fileResult = new FileContentResult(outPdfBuffer, "application/pdf");
            fileResult.FileDownloadName = "File_Links_and_Attachments.pdf";

            return fileResult;
        }
    }
}

HTML Code with Markers for File Links and Attachments

XML

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<!DOCTYPE html>
<html>
<head>
    <title>Add File Links and Attachments to PDF</title>
</head>
<body style="font-family: 'Times New Roman'; font-size: 14px">
    <span style="font-size: 24px; font-weight: bold">File Links</span><br />
    <br />
    <span>The image and the text below will become links to a file from disk:</span>
    <br />
    <br />
    <span data-mapping-enabled="true" data-mapping-id="file_link_text" style="font-size: 16px; font-weight: bold; text-decoration: underline; color: navy">Click to open the external file</span><br />
    <br />
    <img data-mapping-enabled="true" data-mapping-id="file_link_image" alt="Logo Image" style="width: 200px" src="img/logo.jpg" />
    <br />
    <br />
    <span style="font-size: 24px; font-weight: bold">File Attachments</span><br />
    <br />
    <span style="">Click the next icon to open the attachment from a file:</span>
    <span data-mapping-enabled="true" data-mapping-id="attach_from_file_icon">&nbsp;&nbsp;</span><br />
    <br />
    <span style="">Click the next icon to open the attachment from a stream:</span>
    <span data-mapping-enabled="true" data-mapping-id="attach_from_stream_icon">&nbsp;&nbsp;</span><br />
    <br />
</body>
</html>