Showing HTML in PowerPoint

2
votes

My Goal: Want to show HTML in Slide which I dynamically inject into a Master Presentation.

What I've achieved So far: Converted Html to OpenXML (or WordML to be more specific) then Embedded a word object into the PowerPoint and then analyzed the structure via OpenXML SDK Productivity Tool, It has created embeddings folder which contains the document I've selected, The view which I see when I open presentation is basically an Image which is in /ppt/media/image.emf.

Now I've dynamically replaced the contents of embedded docx but how can I generate its image so that I can update the view as well?

Or is there a pain free solution?

2
c#powerpointopenxml
I'm not clear on what exactly you want to do (or the point of the various steps you've taken). Do you want to show examples of HTML code or do you want to embed an HTML page in PPT? If the latter, why not add a browser control and use it to display the page. My friend Shyam Pillai even has a free LiveWeb add-in that more or less automates this for you. You can find it at skp.mvps.org - Steve Rindsberg
@SteveRindsberg I want to inject rendered HTML dynamically into the slide, and will stream the file to the user. Cannot use add-in because it'll create a dependency and my users have to install it. - Ali
The add-in only simplifies the act of adding the browser instance; it creates no dependencies on itself when the file's distributed. Depending on the users' security settings, the browser object itself might be forbidden though. - Steve Rindsberg
This is what I've fount on LiveWeb add-in page: Q- Does the real-time update work without the add-in installed? A - No, you need the add-in. - Ali
That's evidently necessary IF you want the web page to update anew each time you visit the slide where the browser control is embedded during a slide show. You didn't mention that that was necessary. - Steve Rindsberg

2 Answers

1
votes

NOTE: For WINFORMS C#

OK, I didn't go through the pain description you wrote in your query I believe you have shed a lot of sweat to make it work, here I am sharing the pain free solution(at least it worked for me) and I believe it should work for you too.

Create a class as below: (I have taken this solution partially from some other SO, sorry don't remember the source)

using System;
using System.Text.RegularExpressions;
using System.Windows.Forms;


    public class HtmlFragment
    {
        #region Read and decode from clipboard

    static public HtmlFragment FromClipboard()

    {

        string rawClipboardText = Clipboard.GetText(TextDataFormat.Html);

        HtmlFragment h = new HtmlFragment(rawClipboardText);

        return h;

    }


    /// <summary>

    /// Create an HTML fragment decoder around raw HTML text from the clipboard.

    /// This text should have the header.

    /// </summary>

    /// <param name="rawClipboardText">raw html text, with header.</param>

    public HtmlFragment(string rawClipboardText)

    {

        // This decodes CF_HTML, which is an entirely text format using UTF-8.

        // Format of this header is described at:

        // http://msdn.microsoft.com/library/default.asp?url=/workshop/networking/clipboard/htmlclipboard.asp



        // Note the counters are byte counts in the original string, which may be Ansi. So byte counts

        // may be the same as character counts (since sizeof(char) == 1).

        // But System.String is unicode, and so byte couns are no longer the same as character counts,

        // (since sizeof(wchar) == 2).

        int startHMTL = 0;

        int endHTML = 0;


        int startFragment = 0;

        int endFragment = 0;


        Regex r;

        Match m;


        r = new Regex("([a-zA-Z]+):(.+?)[\r\n]",

            RegexOptions.IgnoreCase | RegexOptions.Compiled);


        for (m = r.Match(rawClipboardText); m.Success; m = m.NextMatch())

        {

            string key = m.Groups[1].Value.ToLower();

            string val = m.Groups[2].Value;


            switch(key)

            {

                // Version number of the clipboard. Starting version is 0.9.

                case "version":

                    m_version = val;

                    break;


                // Byte count from the beginning of the clipboard to the start of the context, or -1 if no context

                case "starthtml":

                    if (startHMTL != 0) throw new FormatException("StartHtml is already declared");

                    startHMTL = int.Parse(val);

                    break;


                // Byte count from the beginning of the clipboard to the end of the context, or -1 if no context.

                case "endhtml":

                    if (startHMTL == 0) throw new FormatException("StartHTML must be declared before endHTML");

                    endHTML = int.Parse(val);


                    m_fullText = rawClipboardText.Substring(startHMTL, endHTML - startHMTL);

                    break;


                //  Byte count from the beginning of the clipboard to the start of the fragment.

                case "startfragment":

                    if (startFragment != 0) throw new FormatException("StartFragment is already declared");

                    startFragment = int.Parse(val);

                    break;


                // Byte count from the beginning of the clipboard to the end of the fragment.

                case "endfragment":

                    if (startFragment == 0) throw new FormatException("StartFragment must be declared before EndFragment");

                    endFragment = int.Parse(val);

                    m_fragment = rawClipboardText.Substring(startFragment, endFragment - startFragment);

                    break;


                // Optional Source URL, used for resolving relative links.

                case "sourceurl":

                    m_source = new System.Uri(val);

                    break;

            }

        } // end for


        if (m_fullText == null && m_fragment == null)

        {

            throw new FormatException("No data specified");

        }

    }


    // Data. See properties for descriptions.

    string m_version;

    string m_fullText;

    string m_fragment;

    System.Uri m_source;


    /// <summary>

    /// Get the Version of the html. Usually something like "1.0".

    /// </summary>

    public string Version

    {

        get { return m_version; }

    }


    /// <summary>

    /// Get the full text (context) of the HTML fragment. This includes tags that the HTML is enclosed in.

    /// May be null if context is not specified.

    /// </summary>

    public string Context

    {

        get { return m_fullText; }

    }


    /// <summary>

    /// Get just the fragment of HTML text.

    /// </summary>

    public string Fragment

    {

        get {  return m_fragment; }

    }


    /// <summary>

    /// Get the Source URL of the HTML. May be null if no SourceUrl is specified. This is useful for resolving relative urls.

    /// </summary>

    public System.Uri SourceUrl

    {

        get { return m_source; }

    }


    #endregion // Read and decode from clipboard


    #region Write to Clipboard

    // Helper to convert an integer into an 8 digit string.

    // String must be 8 characters, because it will be used to replace an 8 character string within a larger string.

    static string To8DigitString(int x)

    {

        return String.Format("{0,8}", x);

    }


    /// <summary>

    /// Clears clipboard and copy a HTML fragment to the clipboard. This generates the header.

    /// </summary>

    /// <param name="htmlFragment">A html fragment.</param>

    /// <example>

    ///    HtmlFragment.CopyToClipboard("<b>Hello!</b>");

    /// </example>

    public static void CopyToClipboard(string htmlFragment)

    {

        CopyToClipboard(htmlFragment, null, null);

    }


    /// <summary>

    /// Clears clipboard and copy a HTML fragment to the clipboard, providing additional meta-information.

    /// </summary>

    /// <param name="htmlFragment">a html fragment</param>

    /// <param name="title">optional title of the HTML document (can be null)</param>

    /// <param name="sourceUrl">optional Source URL of the HTML document, for resolving relative links (can be null)</param>

    public static void CopyToClipboard(string htmlFragment, string title, Uri sourceUrl)

    {

        if (title == null) title = "From Clipboard"; 


        System.Text.StringBuilder sb = new System.Text.StringBuilder();


        // Builds the CF_HTML header. See format specification here:

        // http://msdn.microsoft.com/library/default.asp?url=/workshop/networking/clipboard/htmlclipboard.asp


        // The string contains index references to other spots in the string, so we need placeholders so we can compute the offsets.

        // The <<<<<<<_ strings are just placeholders. We’ll backpatch them actual values afterwards.

        // The string layout (<<<) also ensures that it can’t appear in the body of the html because the <

        // character must be escaped.

        string header =

@"Format:HTML Format

Version:1.0

StartHTML:<<<<<<<1

EndHTML:<<<<<<<2

StartFragment:<<<<<<<3

EndFragment:<<<<<<<4

StartSelection:<<<<<<<3

EndSelection:<<<<<<<3

";


        string pre =

@"<!DOCTYPE HTML PUBLIC ""-//W3C//DTD HTML 4.0 Transitional//EN"">

<HTML><HEAD><TITLE>" + title + @"</TITLE></HEAD><BODY><!–StartFragment–>";


        string post = @"<!–EndFragment–></BODY></HTML>";


        sb.Append(header);

        if (sourceUrl != null)

        {

            sb.AppendFormat("SourceURL:{0}", sourceUrl);

        }

        int startHTML = sb.Length;


        sb.Append(pre);

        int fragmentStart = sb.Length;


        sb.Append(htmlFragment);

        int fragmentEnd = sb.Length;


        sb.Append(post);

        int endHTML = sb.Length;


        // Backpatch offsets

        sb.Replace("<<<<<<<1", To8DigitString(startHTML));

        sb.Replace("<<<<<<<2", To8DigitString(endHTML));

        sb.Replace("<<<<<<<3", To8DigitString(fragmentStart));

        sb.Replace("<<<<<<<4", To8DigitString(fragmentEnd));


        // Finally copy to clipboard.

        string data = sb.ToString();

        Clipboard.Clear();

        Clipboard.SetText(data, TextDataFormat.Html);

    }


    #endregion // Write to Clipboard
    }

Usage Explained below :

using PowerPoint = Microsoft.Office.Interop.PowerPoint;

var oPowerPoint = new PowerPoint.Application();
oPowerPoint.Visible = Microsoft.Office.Core.MsoTriState.msoTrue;

I had a requirement to paste the content on the active slide so I used the below code, your logic could be different depending on your need you can ignore the below code line

 var activeSlide = (PowerPoint.Slide)oPowerPoint.ActiveWindow.View.Slide;

Feed your HTML content to the below method

HtmlFragment.CopyToClipboard(HTML CONTENT WILL COME HERE);

Below code will paste the HTML into the active slide 

oPowerPoint.ActiveWindow.View.PasteSpecial();
0
votes

I hope you managed to find something about your issue.

A bit late, but for future people who might come here.

This is for the HTML -> PPT part. 

PowerPoint.Presentation presentation;
presentation = ppApp.Presentations.Open(configuration.PPTTExportedFile, MsoTriState.msoFalse, MsoTriState.msoTrue, MsoTriState.msoTrue);       
foreach (PowerPoint.Slide slide in presentation.Slides)
{
    foreach (PowerPoint.Shape shape in slide.Shapes)
    {
        File.WriteAllText(temporaryFilePath, html);
        WebsiteToImage websiteToImage = new WebsiteToImage(temporaryFilePath, @"New picture path");
        websiteToImage.Generate();
        slide.Shapes.AddPicture(@"picture path", MsoTriState.msoTrue, MsoTriState.msoTrue, oldshapeleft, oldshapetop, oldshapewidth, oldshapeheight);
        fileToDelete.Add(temporaryFilePath);
        fileToDelete.Add(@""dont forget to remove tmp files");
    }
}

Convert webpage to image from ASP.NET

If you want to do any object manipulation in Word/Excel/PowerPoint, I suggest to work with 

Console.Write("AlternativeText: ");
Console.WriteLine(shape.AlternativeText);

Because if you save in your original file an AlternativeText in your object, you can access it fast and you can even change the PATH into a simple variable.

And if you want for example to export a HTML table, do an image from it and change the AlternativeText in order to access it easier later, while giving it an appropriate name that you can access with a 3rd software tool, because PowerPoint doesn't support HTML Tags

Next to do:

File.Copy(WordTemplateFile, WordExportedFile, true);

Why you want to change the original? Just make a copy, and keep it as a template which you can change at any moment while creating a new changed version from it.( good for reports )

AlternativeText is very useful if you plan to work with.

For your replacement, you might want to use NetOffice/Microsoft Office libraries.

foreach (NetOffice.WordApi.InlineShape s in docWord.InlineShapes)
{
    if (s.Type==NetOffice.WordApi.Enums.WdInlineShapeType.wdInlineShapePicture &&  s.AlternativeText.Contains("any pattern you are looking for"))
    {
        <Do your manipulation with image change it>
        s.Range.InsertFile(<insert your new picture for example>);
    }
 }

You loop through all your file and check if something fits your pattern.

Good luck.