Language Server

Language Server Protocol implementation for custom elements. See LSP Integration for editor setup and Using LSP Features for usage guidance.

Supported LSP Methods

Text Document Features

• textDocument/hover - Show element and attribute documentation on hover
• textDocument/completion - Provide tag and attribute completion suggestions
• textDocument/definition - Jump to custom element source definitions
• textDocument/publishDiagnostics - Report validation errors with intelligent suggestions
• textDocument/codeAction - Provide one-click autofixes for validation errors
• textDocument/didOpen - Track when documents are opened in the editor
• textDocument/didChange - Handle incremental document changes
• textDocument/didClose - Clean up resources when documents are closed

Workspace Features

• workspace/symbol - Search and navigate custom elements across the entire workspace

Server Lifecycle

• initialize - Establish server capabilities and workspace configuration
• shutdown - Gracefully terminate the language server
• $/setTrace - Control debug logging verbosity (LSP standard)

Initialization Options

The LSP server accepts custom initialization options for loading additional packages:

{
  "initializationOptions": {
    "additionalPackages": [
      "npm:@rhds/elements@2.0.0",
      "https://cdn.jsdelivr.net/npm/@shortfuse/materialdesignweb/",
      "jsr:@example/elements"
    ]
  }
}

VS Code Example

In your VS Code settings.json:

{
  "cem.additionalPackages": [
    "npm:@rhds/elements@2.0.0",
    "https://cdn.jsdelivr.net/npm/@example/components/"
  ]
}

The VS Code extension passes these as initializationOptions.additionalPackages to the LSP server.

Supported Specifiers

Note: URLs must point to the package root (where package.json lives). The server reads the customElements field from package.json to locate the manifest.