topic Re: How to Decode a Base64 Encoded Bookmark in Developer

How to Decode a Base64 Encoded Bookmark

Log4TurtleShell — Wed, 07 Dec 2022 15:43:07 GMT

I am using this library, https://github.com/microsoft/PowerBI-JavaScript, to embed reports and handle bookmarks. I am calling capture() from the bookmarksManager object on my report. This returns a bookmark with the state. The state is a base64 encoded string. I am trying to decode the string for testing purposes, but I can't get it to decode correctly. I have used Mime tools in Notepad++ and various online decoders, but they all return gibberish.

Is there a trick to decoding base64 encoded bookmark states?

Re: How to Decode a Base64 Encoded Bookmark

Anonymous — Thu, 08 Dec 2022 06:02:38 GMT

Hi @Log4TurtleShell ,

Please review the following links, hope they can help you.

Base64 encoding and decoding in client-side Javascript

How do I decode a Base64 encoded string in JavaScript?

console.log(atob('TXkgU3RyaW5nIFRvIEVuY29kZQ=='));

Base64 Decode a Value in Node.js

const plain = Buffer.from('dXNlcm5hbWU6cGFzc3dvcmQ=', 'base64').toString('utf8')

Best Regards

Re: How to Decode a Base64 Encoded Bookmark

Log4TurtleShell — Thu, 08 Dec 2022 16:54:00 GMT

Thank you for your reply.

Using atob() still returns gibberish. Am I wrong that the bookmark state should be able to be decoded to readable text?

Re: How to Decode a Base64 Encoded Bookmark

ozpbi123 — Thu, 13 Jul 2023 15:04:15 GMT

Did you ever get a solution to this? I am also trying to decode the bookmark state, but unable to get anything other than gibberish as well.

Re: How to Decode a Base64 Encoded Bookmark

Log4TurtleShell — Thu, 13 Jul 2023 15:09:14 GMT

Unfortunately, I did not. 😞

Re: How to Decode a Base64 Encoded Bookmark

klirium — Wed, 06 Mar 2024 11:38:18 GMT

@Log4TurtleShell @ozpbi123

The state of bookmarks is gzipped, so after you decoded it from base64 you need to decompress it:

static class Program { public static void Main() { // Replace with your actual Base64-encoded and gzipped string string encodedAndGzippedString = ""; // Decode the Base64 string byte[] decodedBytes = Convert.FromBase64String(encodedAndGzippedString); // Decompress the gzipped data string decompressedString = DecompressGzip(decodedBytes); Console.WriteLine("Decompressed data:"); Console.WriteLine(decompressedString); } public static string DecompressGzip(byte[] compressedData) { using (var memoryStream = new MemoryStream(compressedData)) using (var gzipStream = new GZipStream(memoryStream, CompressionMode.Decompress)) using (var reader = new StreamReader(gzipStream, Encoding.UTF8)) { return reader.ReadToEnd(); } } }

Re: How to Decode a Base64 Encoded Bookmark

SitiV — Fri, 03 May 2024 06:27:30 GMT

Great post @klirium - we've been struggling with trying to find a way to interpret saved bookmarks to handle updates when a change is made to a report and then the previous saved bookmarks become partially invalid. I haven't tested your code, but I was able to verify the concept of base64 and decompress does work. This site gives a nice way to plug in individual encoded bookmarks and see the plaintext https://www.zickty.com/gziptotext

Re: How to Decode a Base64 Encoded Bookmark

Hettic1 — Tue, 07 Jan 2025 15:57:21 GMT

I did.
You can use below python script to decode the bookmark State.
The output is a JSON. Hope this helps.

Base64 Decode: Convert the Base64-encoded string back to its binary form.
Gzip Decompress: Decompress the binary data to get the original string.

import base64 import gzip from io import BytesIO def decode_base64_gzip(encoded_string): # Step 1: Base64 decode decoded_data = base64.b64decode(encoded_string) # Step 2: Gzip decompress with gzip.GzipFile(fileobj=BytesIO(decoded_data)) as gzip_file: decompressed_data = gzip_file.read() return decompressed_data.decode('utf-8') # Example usage encoded_string = "your_base64_gzipped_string_here" decoded_string = decode_base64_gzip(encoded_string) print(decoded_string)