Preferred way to generate a vscode popup (like "config file not found")

[goto40]

We have a langium plugin (3.5) and we would like to generate a popup in vscode if certain events happen (like config file not found on startup).

Is there a preferred way to do this? Is there something langium specific already existing?

Thank you very much!

[cdietrich]

from server to client? does your client support window/showMessage
then you can do services.shared.lsp.Connection.sendNotification

[goto40]

Sorry. We detect the error in the server. We will send the info to the client and do the show-command there. We were just wondering if there is a possibility (as shortcut) for this "send-error-message-to-client" in langium. Thank you.

[cdietrich]

this is what i showed in my example obove

could look like

    const smp: ShowMessageParams = {
      type: MessageType.Error,
      message: "Mimimi",
    }
    await this.services.shared.lsp?.Connection?.sendNotification(ShowMessageNotification.method, smp)

[goto40]

Thank you very much. We did something similar for a different feature in our software, where we had to send data from the server to the client. This also worked for us here.

The only thing we stumbled over: We were able to do the following with a custom message (ok) - but we were not able to use ShowMessageNotification.method:

• server side: services.lsp.Connection.sendNotification('custom/showErrorMessage', `${e}`);
• client side: client.onNotification('custom/showErrorMessage', (error: string)=>{ vscode.window.showErrorMessage(error); }

However, when using/importing MessageType.Error (e.g. const err=MessageType.Error) in the server code as suggested in the comments above- we got a Error: Cannot find module 'vscode'-error (in language-server\main.cjs). We did not fully understand this error - but out problem is solved (with the custom message).

If this goes too deep we are happy with our solution. Thank you!!
Maybe - with some more hints - we will also be able to fully understand the problem with the standard showMessage feature...

[cdietrich]

wait. where are you importing from?

import {
  ...
  type ShowMessageParams
  MessageType,
  ShowMessageNotification,
} from "vscode-languageserver"

[goto40]

Thank you so much: with this import it works. We somehow had wrong imports (the IDE just inserted it for us and we did not check; we had the type from vsocde-languageclient)- Thank you for the professional help.