Add XML Formatter

package.json

@@ -29,6 +29,14 @@
 		"Languages", "Other"
 	],
 	"main": "./src/main",
+	"contributes": {
+		"commands": [
+			{
+				"command": "xmltools.formatXml",
+				"title": "Format XML"
+			}
+		]
+	},
 	"activationEvents": [
 		"onLanguage:xml"
 	],
@@ -38,7 +46,8 @@
 	},
 	"dependencies": {
 		"semver": "^5.1.0",
-		"request": "^2.67.0"
+		"request": "^2.67.0",
+		"pretty-data": "^0.40.0"
 	},
 	"scripts": {
 		"compile": "node ./node_modules/vscode/bin/compile -watch -p ./"

src/features/xmlFormatting.ts

@@ -0,0 +1,22 @@
+'use strict';
+
+import { TextEditor, TextEditorEdit, TextDocument, Position, Range } from 'vscode';
+
+let pd = require('pretty-data').pd;
+
+export function formatXml(editor: TextEditor, edit: TextEditorEdit): void {
+	let current = editor.document.getText();
+	let pretty = pd.xml(current);
+	
+	// get the range for the entire document
+	let lastLineIndex = (editor.document.lineCount - 1);
+	let lastLine = editor.document.lineAt(lastLineIndex);
+	let lastPosition = lastLine.rangeIncludingLineBreak.end;
+	let range = new Range(new Position(0, 0), lastPosition);
+	
+	// validate the range to ensure it fits inside the document
+	range = editor.document.validateRange(range);
+	
+	// replace the existing xml with the pretty xml
+	edit.replace(range, pretty);
+}