Add "change" event in embed mode with specific changes made to the diagram.

[tyagirajat200]

• I agree to follow the Code of Conduct that this project adheres to.
• I have searched the issue tracker for a feature request that matches the one I want to file, without success.

Is your feature request related to a problem? Please describe.
Yes, Explained below.

Describe the solution you'd like
I am seeking a solution to implement real-time collaboration using Firebase Realtime Database with Draw.io in embedded mode. Currently, I am able to capture the "autosave" event which provides the entire XML of the current diagram view when changes occur. However, I aim to optimize this by capturing and transmitting only the specific changes made to the diagram, rather than the entire XML, to Firebase. This would involve detecting and transmitting the delta changes (i.e., the difference between the previous state and the updated state) to ensure efficient synchronization among users. Upon receiving these changes at other users' ends, a "merge" event would be triggered to integrate the new changes seamlessly into the existing context.

Describe alternatives you've considered
The current approach involves saving and transmitting the complete XML each time a change occurs, followed by a full reload of the diagram at the receiving end using the updated XML. However, this method disrupts the user experience by resetting the layout and focus of the diagram, causing the user's view to jump to the beginning of the diagram. Therefore, I am exploring alternative methods that enable capturing and transmitting only the incremental changes (delta) to minimize disruption and maintain user focus and layout continuity during collaboration sessions.

Additional context
NA

[LSViana]

Hi,

Is any event like this available in the embed mode of draw.io?

[LSViana]

Is there any maintainer that can provide some directions here?

I don't have enough context in the codebase but I'd be happy to provide a PR with this new feature.

[alderg]

Duplicate of #2491

[LSViana]

Hi, @alderg!

Since #2491 is closed, what does it mean for this issue? Is it a valid use case to be implemented?

For example, if I'm using the draw.io embed and I need to know when the user changes the diagram, which of the events documented here should I use?

I noticed the autosave event is the closest one but it seems to be triggered when I push the merge action into the embed (to apply remote changes) as well.