Connection of websocket server with the generated artifacts

[GSri30]

Hello,

I was exploring the Xtext codebase.

Aim: To build a language server and integrate it with my monaco-editor in react app (language client is implemented using monaco-languageclient) via websockets.

Current state: I was looking at few of the existing implementations.
TypeFox/monaco-languageclient#162
https://github.com/nmaoez/composer-language-server

Doubt:
(1) The flow I understood was
monaco-editor -> monaco-languageclient -> websockets (client) <-> websockets (server) <- language server <- custom language grammer
I understand that after writing our custom language grammar, we generate artifacts. Then we implement a websocket server. Then I see we link them by mapping their corresponding input and output streams. Something like this
https://github.com/nmaoez/composer-language-server/blob/0b65a08b106e7e4a89f4c5be9db7f740ceaf207e/com.novomind.language.server.expression.websockets/src/com/novomind/language/server/expression/websockets/RunWebSocketServer3.xtend#LL44-LL46

But the doubt is, we are just using an injector and injecting a LanguageServerImpl class which is common to everyone. How does this know about my grammar and the generated artifacts?
i.e. How is language server <- custom language grammer connection achieved.

[cdietrich]

xtext uses Java Service Loader API to detect language servers. therefor the workflow will generate
mydsl.ide/src-gen/META-INF/services/org.eclipse.xtext.ISetup

=> if you put your dsl to classpath. xtext.ide shared language server (started via the launchers calling injector via ServerModule)
will detect your lang automatically if it is on classpath

[GSri30]

Yeah, I actually used the new project wizard. I have used the fat-jar config.
So how can I configure it to make it use with my custom websocket port? (Assuming the websockets etc are automatically setup from selecting the option to create lang srv in project wizard, along with the launchers)

[cdietrich]

you need to change the config to use your new mainclass.
depends on what you select to do that
by default is uses io main class

[GSri30]

Okay. Ig this is the file in action by default.
https://github.com/eclipse/xtext/blob/main/org.eclipse.xtext.ide/src/org/eclipse/xtext/ide/server/ServerLauncher.java#LL72-LL73

What could be the required config from my end, assuming I want to establish a websocket connection with the language server.

[cdietrich]

you need to check the build.gradle or pom.
there you can specifiy the main class

[GSri30]

So I need to just change the mainClassName that's present here.
Any other config required?

[cdietrich]

no changing the the main class should be sufficient

[GSri30]

Got it.
Thanks for your very quick support!

[cdietrich]