xml.extension.jars to add LemMinX extension jars

Adds a new setting `xml.extension.jars`, where you can list jars to contribute
to the LemMinX classpath. You can use this feature to test LemMinX
extensions in VSCode.

Closes redhat-developer#251

Signed-off-by: David Thompson <davthomp@redhat.com>

docs/Preferences.md

@@ -161,3 +161,15 @@ The different options are:
 Here is a demonstration of the effects of the setting on hovering. The above schema is used in the example:
 
 ![Changing the documentation type setting changes which text the hover shows when hovering over an element that is in a schema document](./images/Preferences/HoverDocumentationQuickDemo.gif)
+
+## Extension JARs
+
+[LemMinX](https://github.com/eclipse/lemminx), the underlying language server that vscode-xml uses to provide most of its functionality,
+is extensible through Java's SPI mechanism.
+Please see [the extension development documentation](https://github.com/eclipse/lemminx/blob/master/docs/LemMinX-Extensions.md) for more information on how this works.
+
+JARs can be contributed to the LemMinX classpath using the `xml.extension.jars` preference.
+These paths can include globs.
+This feature is only intended to be used for LemMinX extension development purposes.
+Distributing vscode-xml extensions is best done through the mechanism described in the
+[vscode-xml extension development documentation](https://github.com/redhat-developer/vscode-xml/wiki/Extensions).

package.json

@@ -355,7 +355,13 @@
         "xml.symbols.showReferencedGrammars": {
           "type": "boolean",
           "default": true,
-          "markdownDescription": "Show referenced grammars in the Outline. Default is `true.",
+          "markdownDescription": "Show referenced grammars in the Outline. Default is `true`.",
+          "scope": "window"
+        },
+        "xml.extension.jars": {
+          "type": "array",
+          "default": [],
+          "markdownDescription": "An array of paths to JARs that should be contributed to the LemMinX classpath. This is intended to be used as a tool for developing extensions to vscode-xml. Please see [here](command:xml.open.docs?%5B%7B%22page%22%3A%22Preferences%22%2C%22section%22%3A%22extension-jars%22%7D%5D) for more information",
           "scope": "window"
         }
       }

src/extension.ts

@@ -18,7 +18,7 @@ import * as path from 'path';
 import * as os from 'os';
 import { activateTagClosing, AutoCloseResult } from './tagClosing';
 import { Commands } from './commands';
-import { onConfigurationChange, subscribeJDKChangeConfiguration } from './settings';
+import { getXMLConfiguration, onConfigurationChange, subscribeJDKChangeConfiguration } from './settings';
 import { collectXmlJavaExtensions, onExtensionChange } from './plugin';
 import { markdownPreviewProvider } from "./markdownPreviewProvider";
 
@@ -203,7 +203,7 @@ export function activate(context: ExtensionContext) {
       }
     }
 
-    let serverOptions = prepareExecutable(requirements, collectXmlJavaExtensions(extensions.all), context);
+    let serverOptions = prepareExecutable(requirements, collectXmlJavaExtensions(extensions.all, getXMLConfiguration().get("extension.jars", [])), context);
     languageClient = new LanguageClient('xml', 'XML Support', serverOptions, clientOptions);
     let toDispose = context.subscriptions;
     let disposable = languageClient.start();
@@ -245,7 +245,7 @@ export function activate(context: ExtensionContext) {
 
       if (extensions.onDidChange) {// Theia doesn't support this API yet
         context.subscriptions.push(extensions.onDidChange(() => {
-          onExtensionChange(extensions.all);
+          onExtensionChange(extensions.all, getXMLConfiguration().get("extension.jars", []));
         }));
       }
 

src/plugin.ts

@@ -7,7 +7,7 @@ const glob = require('glob');
 
 let existingExtensions: Array<string>;
 
-export function collectXmlJavaExtensions(extensions: readonly vscode.Extension<any>[]): string[] {
+export function collectXmlJavaExtensions(extensions: readonly vscode.Extension<any>[], jars: string[]): string[] {
 	const result = [];
 	if (extensions && extensions.length) {
 		for (const extension of extensions) {
@@ -22,17 +22,20 @@ export function collectXmlJavaExtensions(extensions: readonly vscode.Extension<a
 			}
 		}
 	}
+	for (const extension of jars) {
+		result.push(...glob.sync(extension));
+	}
 	// Make a copy of extensions:
 	existingExtensions = result.slice();
 	return result;
 }
 
-export function onExtensionChange(extensions: readonly vscode.Extension<any>[]) {
+export function onExtensionChange(extensions: readonly vscode.Extension<any>[], jars: string[]) {
 	if (!existingExtensions) {
 		return;
 	}
 	const oldExtensions = new Set(existingExtensions.slice());
-	const newExtensions = collectXmlJavaExtensions(extensions);
+	const newExtensions = collectXmlJavaExtensions(extensions, jars);
 	let hasChanged = ( oldExtensions.size !== newExtensions.length);
 	if (!hasChanged) {
 		for (const newExtension of newExtensions) {