Merge branch 'interpolation' of https://github.com/calvinmetcalf/Leaflet

* 'interpolation' of https://github.com/calvinmetcalf/Leaflet:
  '#1968 compiled interpolation'

spec/suites/core/UtilSpec.js

@@ -189,16 +189,45 @@ describe('Util', function() {
 
 	describe('#template', function () {
 		it('evaluates templates with a given data object', function () {
-			var tpl = 'Hello {foo} and {bar}!';
+			var tpl = 'Hello {foo} and {baz }!';
 
 			var str = L.Util.template(tpl, {
 				foo: 'Vlad',
-				bar: 'Dave'
+				bar: 'Dave',
+				baz:function(o){
+					return o.bar;
+				}
 			});
 
 			expect(str).to.eql('Hello Vlad and Dave!');
 		});
+		it('check the cache', function () {
+			var tpl = 'Hello {foo} and {baz }!';
 
+			var str = L.Util.templateCache[tpl]({
+				foo: 'ladies',
+				baz: function(){
+					return 'gentlemen';
+				}
+			});
+
+			expect(str).to.eql('Hello ladies and gentlemen!');
+		});
+		it('evaluates templates with a function', function () {
+			var tpl = L.Util.compileTemplate('Hello { foo } and { bar}!',{});
+
+			var str1 = tpl({
+				foo: 'Vlad',
+				bar: 'Dave'
+			});
+			var str2 = tpl({
+				foo: '{Calvin}',
+				bar: '{Simon}'
+			});
+
+			expect(str1).to.eql('Hello Vlad and Dave!');
+			expect(str2).to.eql('Hello {Calvin} and {Simon}!');
+		});
 		it('does not modify text without a token variable', function () {
 			expect(L.Util.template('foo', {})).to.eql('foo');
 		});

src/core/Util.js

@@ -104,17 +104,33 @@ L.Util = {
 		}
 		return ((!existingUrl || existingUrl.indexOf('?') === -1) ? '?' : '&') + params.join('&');
 	},
-
+	
+	compileTemplate: function (str, data) {
+		/*jslint evil: true */
+		//from https://gist.github.com/padolsey/6008842
+		return new Function(
+			'o',
+			'return "' + (
+				str.replace(/\"/g, '\\"').replace(/\{ *([\w_]+) *\}/g, function (_, $1) {
+					if (typeof data[$1] === 'function') {
+						return '" + o["' + $1 + '"](o) + "';
+					} else {
+						return '" + o["' + $1 + '"] + "';
+					}
+				})
+			) + '";'
+		);
+	},
+	
+	templateCache: {},
+	
 	template: function (str, data) {
-		return str.replace(/\{ *([\w_]+) *\}/g, function (str, key) {
-			var value = data[key];
-			if (value === undefined) {
-				throw new Error('No value provided for variable ' + str);
-			} else if (typeof value === 'function') {
-				value = value(data);
-			}
-			return value;
-		});
+		if (str in this.templateCache) {
+			return this.templateCache[str](data);
+		} else {
+			this.templateCache[str] = this.compileTemplate(str, data);
+			return this.templateCache[str](data);
+		}
 	},
 
 	isArray: function (obj) {