Maintain Diagnostic on Non File Node

[kapishsingla]

Hi,

In theia, I have extended the FileNavigatorWidget to serve the purpose of showing the components of document as a non-file Node in Navigator.

Theia currently uses LSP with Langium documents to generate diagnostics and display markers on files in the Navigator, working at the document level. I want to adjust this so diagnostics are maintained and retrieved based on non-file nodes. This way, I can get diagnostics specific to a non-file node and display markers only on that particular node.

Could you please suggest any approach for the same?

[spoenemann]

Hi @kapishsingla! I would create a custom JSON-RPC message where you send exactly the information you need in your Navigator tree. Here's an example for this:

langium/examples/statemachine/src/language-server/main-browser.ts

Lines 25 to 38 in 21b1051

	// Send a notification with the serialized AST after every document change
	type DocumentChange = { uri: string, content: string, diagnostics: Diagnostic[] };
	const documentChangeNotification = new NotificationType<DocumentChange>('browser/DocumentChange');
	const jsonSerializer = statemachine.serializer.JsonSerializer;
	shared.workspace.DocumentBuilder.onBuildPhase(DocumentState.Validated, documents => {
	for (const document of documents) {
	const json = jsonSerializer.serialize(document.parseResult.value);
	connection.sendNotification(documentChangeNotification, {
	uri: document.uri.toString(),
	content: json,
	diagnostics: document.diagnostics ?? []
	});
	}
	});

The example sends the whole serialized AST. In your case, you rather need information about validation results and to which nodes they belong.

Then you need corresponding code on the VS Code extension side to register a message handler on the JSON-RPC connection.