Power Platform Community Forum Thread Details

Greetings!

I have an old Infopath system stored in SharePoint. Now I'm trying to use Power Automate to extract embedded images from there. I found how to get text part which represents image inside. So for example "x0lGQRAAA...." here is image header and image content, as I understand:

But here I stucked. I know how to create html file but cannot convert infopath encoded string to html:

Tried to use this string like this, but this does not work:

As I understand there is encoded header in this string, this is not clear file content.

Also tried to use base64ToBinary conversion and then extract content like described here

outputs('Compose_base64ToBinary')?['body/$content']

But it also does not work, base64ToBinary has same string in 'content':

How to convert this infopath string to something I can work. Or how to decode header and image content (some images could have *.png type, and other *.jpg, etc.)

Categories:

General topics

Update:

So Infopath XML stores embedded images in base64 string, which contains file name/type and file content. Here are two embedded images:

In Infopath XML this image is stored like base64 string:

<my:group4>
 <my:field18>
 <!-- jpg-image.jpg encoded in infopath form: -->
 x0lGQRQAAAABAAAAAAAAAO+aAAAOAAAAcABuAGcALQBpAG0AYQBnAGUALgB...
 </my:field18>
</my:group4>

First part contains file name and the second is encoded image.

We can use encoded image part in html as image content like this:

<img src="data%3Aimage/png;base64,iVBORw0KGgoAAAANSUhEUgAAABkAA..." />

But xml string in Infopath stores both filename and content in one line, so I need to read some bytes and split file name and image content

Here I put examples of InfoPath string and C# code, that decodes it and get file name/and content strings:

https://gist.github.com/Gennady-G/48d740c92593e1ce8234b4a8c3a23069

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Xml;
using System.Xml.XPath;
using System.Security.Cryptography;
using System.IO;


namespace getFilenameFromBase64
{
 class Program
 {

 // "jpg-image.jpg" file encoded in infopath xml
 private static string base64FromInfopath = "x0lGQRQAAAABAAAAAAAAAPBgAAAOAAAAa....";

 // "png-image.png"
 //private static string base64FromInfopath = "x0lGQRQAAAABAAAAAAAAAO+aAAAOAAAAc...";

 static void Main(string[] args)
 {
 // This function from Quazi Anis gets filename from encoded string
 // https://www.infopathdev.com/forums/p/15120/53720.aspx#53720
 Encoding _encoding = Encoding.Unicode;

 // Read base64 string and get header, filename and image content separately
 using (MemoryStream _memoryStream = new MemoryStream(Convert.FromBase64String(Program.base64FromInfopath)))
 {
 BinaryReader _theReader = new BinaryReader(_memoryStream);
 byte[] _headerData = _theReader.ReadBytes(16);
 int _fileSize = (int)_theReader.ReadUInt32();

 int _imageNameLength = (int)_theReader.ReadUInt32() * 2;
 byte[] _fileNameBytes = _theReader.ReadBytes(_imageNameLength);

 // here is file name decoded:
 string fileName = _encoding.GetString(_fileNameBytes, 0, _imageNameLength - 2);
 Console.WriteLine(fileName); // result: "jpg-image.jpg"

 // and here is base64 data of pure image that we can use in html: <img src="data&colon;image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAqMAAAIZCAIAAAAdrK.." />
 var imageContentInBytes = _theReader.ReadBytes(_fileSize);
 var imageContentAsString = Convert.ToBase64String(imageContentInBytes); // result: "iVBORw0KGgoAAAANSUhEUgAAAqMAAAIZCAIAAAAdrK.."

 Console.WriteLine(imageContentAsString);
 }
 }
 }
}

Here are project sources if needed:

https://github.com/Gennady-G/ExtractImageFromInfopathXml/blob/main/getFilenameFromBase64/getFilenameFromBase64/Program.cs

Can I do something similar (make operations with bytes array) in SharePoint power automate? Or what You think I can do to decode base64 string and extract file name/type and image content from there?