Other than the general diagnostics, there are XML plug-in specific actions that the user can perform.

Verifying the state of the XML language server

Procedure

  1. Open a terminal in the container named vscode-xml-<xxx>.

  2. Run ps aux | grep java to verify that the XML language server has started. The output should be:

    java ***/org.eclipse.ls4xml-uber.jar`

    If not, see Checking important logs.

Checking XML language server feature flags

Procedure

  1. Check if the features are enabled. The XML plug-in provides multiple settings that can enable and disable features:

    • xml.format.enabled: Enable the formatter

    • xml.validation.enabled: Enable the validation

    • xml.documentSymbols.enabled: Enable the document symbols

  2. To diagnose whether the XML language server is working, create a simple XML element, such as <hello></hello>, and confirm that it appears in the Outline panel on the right.

  3. If the document symbols do not show, ensure that the xml.documentSymbols.enabled attribute is set to true. If it is true, and there are no symbols, the language server may not be hooked to the editor. If there are document symbols, then the language server is connected to the editor.

  4. Ensure that the features that the user needs, are set to true in the settings (they are set to true by default). If any of the features are not working, or not working as expected, file an issue against the Language Server.

Enabling XML Language Server Protocol (LSP) tracing

Procedure

To log LSP messages to the VS Code Output view, enable tracing by setting the xml.trace.server attribute to verbose.

Viewing the XML language server log

Procedure

The log from the language server can be found in the plug-in sidecar at /home/theia/.theia/workspace-storage/<workspace_name>/redhat.vscode-xml/lsp4xml.log.