Is Java - EMF - VS Code combination possible?

[ichlaffterlalu]

Let me tell the background a bit. My team and I currently build and maintain a fork of FeatureIDE (https://featureide.github.io/) to support development of web software product lines.
FeatureIDE itself is an Eclipse-based IDE to build software product lines. It relies heavily on the Eclipse Modelling Framework (EMF).
EMF is used to draw/design UML models and build codes using model-to-text transformation tools.

Unfortunately, using Eclipse as the IDE doesn't appeal majority of the market here in our country, so that we have the urgency to support web software product lines using other IDEs, such as VS Code.
We found this Eclipse GLSP project interesting as it can port Eclipse Modelling Framework (EMF) to non-Eclipse platforms.

Currently, in the examples, there is Node - Custom JSON - VS Code and Java - EMF - Theia.
We understand that Theia itself is a derivative of VS Code, but in this case, we want to use the original VS Code.
So we want to ask for help regarding the feasibility of Java - EMF - VS Code combination.
Can VS Code extensions and webview be combined with Java-based EMF, or using custom JSONs are the only option?
So far, we don't think it is possible to cover UML diagrams using JSON models, as thorough as EMF currently able to.

As we are new to the project, any guidance will be helpful, especially when we need to make our own variant of GLSP server for example.
Thank you in advance.

[tortmayr]

Thank you for your interest in Eclipse GLSP and for sharing the background of your project.

GLSP Architecture & Java-EMF Integration with VS Code

GLSP is designed with a flexible, decoupled architecture. It allows you to combine any backend/server implementation (e.g., Java-based with EMF models) with a frontend/client integration (e.g., VS Code extension using webviews). So, your intended combination—Java + EMF on the server side, with a VS Code extension as the frontend—is absolutely feasible and aligns well with GLSP’s design.

GLSP communicates between client and server via a well-defined protocol (using JSON over WebSockets/Sockets), so the frontend does not need to know the backend model implementation details. This means you can leverage your existing EMF-based models and business logic in Java, and connect them to a custom GLSP-based VS Code extension that renders and edits diagrams in the browser/webview.

References & Examples

If you are looking for a real-world reference, check out bigUml (https://github.com/borkdominik/bigUml).
It provides a complete example of a Java/EMF-based GLSP server integrating with VS Code.

[ichlaffterlalu]

Thank you @tortmayr for your amazing explanation and examples. I'm glad that you have example for UML too.
Gotta check it out soon.

This is a bit out of topic, but, when I try to run java-emf-theia example, I am stuck with node-gyp compiling issues in Windows. Seems like they need Python 2.7 to compile in Windows. However, as far as I know, node-gyp 6 and above should be able to compile using Python 3, so it seems that the GLSP examples are using outdated node-gyp. I didn't see any direct node-gyp dependency there, but maybe some of the dependencies might use outdated version of node-gyp.

[tortmayr]

Thanks for raising this. I can reproduce the problem and have opened #1576 to track this.