Refactored link macro

To handle external links correctly, and URI encode internal links

js/macros/link.js

@@ -10,6 +10,11 @@ title: js/macros/link.js
 var HTML = require("../HTML.js").HTML,
 	utils = require("../Utils.js");
 
+var isLinkExternal = function(target) {
+	var externalRegExp = /(?:file|http|https|mailto|ftp|irc|news|data):[^\s'"]+(?:\/|\b)/i;
+	return externalRegExp.test(target);
+};
+
 exports.macro = {
 	name: "link",
 	wrapperTag: "span",
@@ -19,19 +24,37 @@ exports.macro = {
 	},
 	events: {
 		click: function(event,node,tiddler,store,params) {
-			var navEvent = document.createEvent("Event");
-			navEvent.initEvent("tw-navigate",true,true);
-			navEvent.navigateTo = params.target;
-			node.dispatchEvent(navEvent); 
-			event.preventDefault();
-			return false;
+			if(isLinkExternal(params.target)) {
+				event.target.setAttribute("target","_blank");
+				return true;
+			} else {
+				var navEvent = document.createEvent("Event");
+				navEvent.initEvent("tw-navigate",true,true);
+				navEvent.navigateTo = params.target;
+				node.dispatchEvent(navEvent); 
+				event.preventDefault();
+				return false;
+			}
 		}
 	},
 	render: function(type,tiddler,store,params,content) {
+		var classes = ["tw-tiddlylink"],
+			target = params.target;
+		if(isLinkExternal(params.target)) {
+			classes.push("tw-tiddlylink-external");
+		} else {
+			classes.push("tw-tiddlylink-internal");
+			if(store.tiddlerExists(params.target)) {
+				classes.push("tw-tiddlylink-resolves");
+			} else {
+				classes.push("tw-tiddlylink-missing");
+			}
+			target = encodeURIComponent(target);
+		}
 		return HTML(HTML.elem(
 							"a",{
-								href: params.target,
-								"class": store.adjustClassesForLink([],params.target)
+								href: target,
+								"class": classes
 							},[
 								HTML.raw(content)
 							]