How to Handle File Operations

[ballcoach12]

My editor is hosted in the browser with the language server running in a web worker so I am wondering how should we go about handling file operations in the language server where you are outside of the Node context.

We could send LSP messages from the client in the browser to the server in the worker, but I am wondering if this is already handled for us in Langium v3.0.0 using the workspace. My guess is that I should implement a custom FileSystemProvider that can provide the linkage between the browser-managed file system and the DefaultWorkspaceManager. My goal is to synchronize the create/open/rename/delete/close operations for files in our editing environment.

Am I thinking about this correctly?

[msujew]

Hey @ballcoach12,

open/change operations should be handled by the language server by default using the appropriate editor LSP messages. For creation/deletion and rename (which is effectively just a deletion + creation), you will need the workspace/didChangeWatchedFiles notification. I assume that you can hook into the language client you're using (monaco-languageclient?) and send the notification yourself if you register a change in the workspace.

Note that the language server will then attempt to load the created document, so you need a browser based implementation of FileSystemProvider that is capable of loading the file somehow across the webworker border.

[cdietrich]

btw this is the way i did it in the example mentioned before.
we open the to be edited file in the foreground and all other files (imported ones) in the background using monacos createModelReference

[kaisalmen]

@cdietrich using vscode.workspace.openTextDocument may be interesting for you as well

[kaisalmen]

@ballcoach12 and @cdietrich sorry for coming up with this proposal only now. I sometimes forget we have all those capabilities. 😅 I updated the python client example with the bespoke code

[kaisalmen]

Thanks @kaisalmen. I think I am close to having this working with the latest m-e-w version. However, it looks like the editorWorker-es.js file can't be found. Is buildWorkerDefinition() still the correct way to load it? I noticed that your code example has a configureMonacoWorkers() function. Does that tell the worker factory where to find the worker js file?

I received this notification, but I don't see it here. 🤔 buildWorkerDefinition is outdated. I introduced configureMonacoWorkers with v4 of the wrapper. The new function is more flexible. You can use the bundle version like this: https://github.com/TypeFox/monaco-languageclient/blob/main/packages/examples/src/python/client/main.ts#L14-L18 or fully override the instructions like here: https://github.com/TypeFox/monaco-languageclient/blob/main/packages/examples/src/ts/wrapperTs.ts#L16-L23

[ballcoach12]

Sorry for the confusion, @kaisalmen. After I made the post, I figured out the code changes that I needed to make and didn't want to waste anyone's time. Thank you for the response, though. It sheds even more light on how things work.