Add XPath Engine

package.json

@@ -38,6 +38,10 @@
 			{
 				"command": "xmltools.linearizeXml",
 				"title": "XML Tools: Linearize XML"
+			},
+			{
+				"command": "xmltools.evaluateXPath",
+				"title": "XML Tools: Evaluate XPath"
 			}
 		]
 	},
@@ -51,7 +55,9 @@
 	"dependencies": {
 		"semver": "^5.1.0",
 		"request": "^2.67.0",
-		"pretty-data": "^0.40.0"
+		"pretty-data": "^0.40.0",
+		"xmldom": "^0.1.19",
+		"xpath": "^0.0.9"
 	},
 	"scripts": {
 		"compile": "node ./node_modules/vscode/bin/compile -watch -p ./"

src/features/xmlXPathEngine.ts

@@ -0,0 +1,43 @@
+'use strict';
+
+import { window, TextEditor, TextEditorEdit, OutputChannel, ViewColumn } from 'vscode';
+
+let xpath = require('xpath');
+let dom = require('xmldom').DOMParser;
+let resultChannel: OutputChannel = null;
+
+export function evaluateXPath(editor: TextEditor, edit: TextEditorEdit): void {
+	window.showInputBox({
+		placeHolder: 'XPath Query',
+		prompt: 'Please enter an XPath query to evaluate.'
+		
+	}).then((query) => {
+		if (query === undefined) return;
+		
+		let xml = editor.document.getText();
+		let doc = new dom().parseFromString(xml);
+		
+		try {
+			var nodes = xpath.select(query, doc);
+		}
+		
+		catch (ex) {
+			window.showErrorMessage(ex);
+			return;
+		}
+		
+		if (nodes === null || nodes === undefined || nodes.length == 0) {
+			window.showInformationMessage('Your XPath query returned no results.');
+			return;
+		}
+
+		if (resultChannel === null) resultChannel = window.createOutputChannel('XPath Evaluation Results');
+		resultChannel.clear();
+		
+		nodes.forEach((node) => {
+			resultChannel.appendLine(`${node.localName}: ${node.firstChild.data}`);
+		});
+		
+		resultChannel.show(ViewColumn.Three);
+	});
+}

src/main.ts

@@ -2,6 +2,7 @@
 
 import { commands, ExtensionContext } from 'vscode';
 import { formatXml, linearizeXml } from './features/xmlFormatting';
+import { evaluateXPath } from './features/xmlXPathEngine';
 
 export function activate(ctx: ExtensionContext) {
 	// check for update
@@ -10,4 +11,5 @@ export function activate(ctx: ExtensionContext) {
 	// register pallete commands
 	ctx.subscriptions.push(commands.registerTextEditorCommand('xmltools.formatXml', formatXml));
 	ctx.subscriptions.push(commands.registerTextEditorCommand('xmltools.linearizeXml', linearizeXml));
+	ctx.subscriptions.push(commands.registerTextEditorCommand('xmltools.evaluateXPath', evaluateXPath));
 }