Merge Multiple HTML Pages into a Single PDF

using System;
using System.Collections.Generic;
using System.Linq;
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.HTML_to_PDF.Headers_and_Footers
{
    public class Header_Footer_on_Merged_HTMLController : Controller
    {
        IFormCollection formCollection;

        private readonly Microsoft.AspNetCore.Hosting.IWebHostEnvironment m_hostingEnvironment;
        public Header_Footer_on_Merged_HTMLController(IWebHostEnvironment hostingEnvironment)
        {
            m_hostingEnvironment = hostingEnvironment;
        }

        [HttpPost]
        public ActionResult ConvertHtmlToPdf(IFormCollection collection)
        {
            formCollection = 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 a PDF document
            Document pdfDocument = null;
            if (useTcpService)
                pdfDocument = new Document(serverIP, serverPort);
            else
                pdfDocument = new Document(true, webServiceUrl);

            // Set optional service password
            if (useServicePassword)
                pdfDocument.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
            pdfDocument.LicenseKey = "4W9+bn19bn5ue2B+bn1/YH98YHd3d3c=";

            // Add a page to PDF document
            PdfPage firstPdfPage = pdfDocument.AddPage();

            // Create Header
            if (collection["addHeaderCheckBox"].Count > 0)
                CreateHeader(pdfDocument, collection["drawHeaderLineCheckBox"].Count > 0);

            // Create Footer
            if (collection["addFooterCheckBox"].Count > 0)
                CreateFooter(pdfDocument, collection["drawFooterLineCheckBox"].Count > 0, collection["addPageNumbersInFooterCheckBox"].Count > 0);

            // Add First HTML

            // Create the first HTML to PDF element
            HtmlToPdfElement firstHtml = new HtmlToPdfElement(0, 0, collection["firstUrlTextBox"]);

            // Optionally set a delay before conversion to allow asynchonous scripts to finish
            firstHtml.ConversionDelay = 2;

            // Optionally add a space between header and the content generated by this HTML to PDF element
            // The spacing for first page and the subsequent pages can be set independently
            // Leave this option not set for no spacing
            firstHtml.Y = float.Parse(collection["firstPageSpacingTextBox"]);
            firstHtml.TopSpacing = float.Parse(collection["headerSpacingTextBox"]);

            // Optionally add a space between footer and the content generated by this HTML to PDF element
            // Leave this option not set for no spacing
            firstHtml.BottomSpacing = float.Parse(collection["footerSpacingTextBox"]);

            // Set the header visibility in first, odd and even pages
            if (collection["addHeaderCheckBox"].Count > 0)
            {
                firstPdfPage.ShowHeader = collection["showHeaderInFirstPageCheckBox"].Count > 0;
                firstHtml.ShowHeaderInEvenPages = collection["showHeaderInEvenPagesCheckBox"].Count > 0;
                firstHtml.ShowHeaderInOddPages = collection["showHeaderInOddPagesCheckBox"].Count > 0;
            }

            // Set the footer visibility in first, odd and even pages
            if (collection["addFooterCheckBox"].Count > 0)
            {
                firstPdfPage.ShowFooter = collection["showFooterInFirstPageCheckBox"].Count > 0;
                firstHtml.ShowFooterInEvenPages = collection["showFooterInEvenPagesCheckBox"].Count > 0;
                firstHtml.ShowFooterInOddPages = collection["showFooterInOddPagesCheckBox"].Count > 0;
            }

            // Add the first HTML to PDF element to PDF document
            firstPdfPage.AddElement(firstHtml);

            // Add Second HTML

            // Create the second HTML to PDF element
            HtmlToPdfElement secondHtml = new HtmlToPdfElement(0, 0, collection["secondUrlTextBox"]);

            // Optionally set a delay before conversion to allow asynchonous scripts to finish
            secondHtml.ConversionDelay = 2;

            // Optionally add a space between header and the content generated by this HTML to PDF element
            // Leave this option not set for no spacing
            secondHtml.TopSpacing = float.Parse(collection["headerSpacingTextBox"]);

            // Optionally add a space between footer and the content generated by this HTML to PDF element
            // Leave this option not set for no spacing
            secondHtml.BottomSpacing = float.Parse(collection["footerSpacingTextBox"]);

            // Set the header visibility in odd and even pages
            if (collection["addHeaderCheckBox"].Count > 0)
            {
                secondHtml.ShowHeaderInEvenPages = collection["showHeaderInEvenPagesCheckBox"].Count > 0;
                secondHtml.ShowHeaderInOddPages = collection["showHeaderInOddPagesCheckBox"].Count > 0;
            }

            // Set the footer visibility in odd and even pages
            if (collection["addFooterCheckBox"].Count > 0)
            {
                secondHtml.ShowFooterInEvenPages = collection["showFooterInEvenPagesCheckBox"].Count > 0;
                secondHtml.ShowFooterInOddPages = collection["showFooterInOddPagesCheckBox"].Count > 0;
            }

            if (collection["startNewPageCheckBox"].Count > 0)
            {
                // Create a PDF page where to add the second HTML
                PdfPage secondPdfPage = pdfDocument.AddPage();
                // Add the second HTML to PDF element to PDF document at the beginnig of the new PDF page 
                secondPdfPage.AddElement(secondHtml);
            }
            else
            {
                // Add the second HTML to PDF element to PDF document write after the last added element
                pdfDocument.AddElement(secondHtml);
            }

            // 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 = "Merge_Multipe_HTML.pdf";

            return fileResult;
        }

        /// <summary>
        /// Creates the document header
        /// </summary>
        /// <param name="pdfDocument">The PDF document object</param>
        /// <param name="drawHeaderLine">A flag indicating if a line should be drawn at the bottom of the header</param>
        private void CreateHeader(Document pdfDocument, bool drawHeaderLine)
        {
            string headerHtmlString = System.IO.File.ReadAllText(m_hostingEnvironment.ContentRootPath + "/wwwroot" + "/DemoAppFiles/Input/HTML_Files/Header_HTML.html");
            string headerBaseUrl = "http://www.evopdf.com/demo/DemoAppFiles/Input/HTML_Files/";

            // Add a header to document having 60 points in height
            pdfDocument.AddHeaderTemplate(60);

            // Create a HTML element to be added in header
            HtmlToPdfElement headerHtml = new HtmlToPdfElement(headerHtmlString, headerBaseUrl);

            // Set the HTML element to fit the container height
            headerHtml.FitHeight = true;

            // Add HTML element to header
            pdfDocument.Header.AddElement(headerHtml);

            if (drawHeaderLine)
            {
                PdfPage firstPage = pdfDocument.GetPage(0);
                float headerWidth = firstPage.PageSize.Width - firstPage.Margins.Left - firstPage.Margins.Right;
                float headerHeight = pdfDocument.Header.Height;

                // Create a line element for the bottom of the header
                LineElement headerLine = new LineElement(0, headerHeight - 1, headerWidth, headerHeight - 1);

                // Set line color
                headerLine.ForeColor = RgbColor.Gray;

                // Add line element to the bottom of the header
                pdfDocument.Header.AddElement(headerLine);
            }
        }

        /// <summary>
        /// Creates the document footer
        /// </summary>
        /// <param name="htmlToPdfConverter">The HTML to PDF Converter object</param>
        /// <param name="addPageNumbers">A flag indicating if the page numbering is present in footer</param>
        /// <param name="drawFooterLine">A flag indicating if a line should be drawn at the top of the footer</param>
        private void CreateFooter(Document pdfDocument, bool addPageNumbers, bool drawFooterLine)
        {
            string footerHtmlString = System.IO.File.ReadAllText(m_hostingEnvironment.ContentRootPath + "/wwwroot" + "/DemoAppFiles/Input/HTML_Files/Footer_HTML.html");
            string footerBaseUrl = "http://www.evopdf.com/demo/DemoAppFiles/Input/HTML_Files/";

            // Add a footer to document having 60 points in height
            pdfDocument.AddFooterTemplate(60);

            // Create a HTML element to be added in footer
            HtmlToPdfElement footerHtml = new HtmlToPdfElement(footerHtmlString, footerBaseUrl);

            // Set the HTML element to fit the container height
            footerHtml.FitHeight = true;

            // Add HTML element to footer
            pdfDocument.Footer.AddElement(footerHtml);

            // Add page numbering
            if (addPageNumbers)
            {
                // Create a text element with page numbering place holders &p; and & P;
                TextElement footerText = new TextElement(0, 30, "Page &p; of &P;  ", new PdfFont("Times New Roman", 10, true));

                // Align the text at the right of the footer
                footerText.TextAlign = HorizontalTextAlign.Right;

                // Set page numbering text color
                footerText.ForeColor = RgbColor.Navy;

                // Embed the text element font in PDF
                footerText.EmbedSysFont = true;

                // Add the text element to footer
                pdfDocument.Footer.AddElement(footerText);
            }

            if (drawFooterLine)
            {
                // Calculate the footer width based on PDF page size and margins
                PdfPage firstPage = pdfDocument.GetPage(0);
                float footerWidth = firstPage.PageSize.Width - firstPage.Margins.Left - firstPage.Margins.Right;

                // Create a line element for the top of the footer
                LineElement footerLine = new LineElement(0, 0, footerWidth, 0);

                // Set line color
                footerLine.ForeColor = RgbColor.Gray;

                // Add line element to the bottom of the footer
                pdfDocument.Footer.AddElement(footerLine);
            }
        }
    }
}