Websocket Text Relay

This Javascript code implements a VS Code extension that relays text document changes over WebSockets. Here's a breakdown:

Core Functionality:

• Websocket Communication: The extension establishes a WebSocket connection to a server (defined in server.js).
• Real-time Text Synchronization: It uses the vscode-languageclient library to synchronize text document changes between VS Code and the server.
• Selective Synchronization: Only changes to files specified by the server are synchronized.

How it Works:

1. Activation (activate function):

   • Logs an activation message.
   • Reads configuration settings for the WebSocket server (command, arguments, network access permissions).
   • Creates a LanguageClient instance to manage the WebSocket connection and communication with the server.
   • Starts the client to establish the connection.
   • Sets up event listeners for when text documents are opened or closed in VS Code.
   • Sends an initial notification to the server with a list of currently open files.

2. Handling Open/Close Events:

   • When a text document is opened or closed, the updateOpenFiles function is triggered.
   • This function collects the file paths of all currently open documents in VS Code.
   • It sends a notification (wtr/update-open-files) to the server with the updated list of open files.

3. Server-Controlled Synchronization:

   • The server determines which files should have their changes synchronized.
   • The server sends a notification (wtr/update-active-files) to the extension with a list of "active" files.
   • The extension listens for this notification and calls the updateRegistrations function.

4. Updating Synchronized Files (updateRegistrations function):

   • This function updates the LanguageClient's registrations to only synchronize changes for the specified "active" files.
   • It first unregisters any previous registrations for the textDocument/didChange feature.
   • Then, it registers the feature again with a document selector that only includes the "active" files.

5. Deactivation (deactivate function):

   • Stops the LanguageClient to close the WebSocket connection when the extension is deactivated.

In essence: This extension acts as a bridge, allowing a server to selectively receive and potentially modify real-time text edits made in VS Code. The server controls which files are synchronized and can implement custom logic based on the received changes.