Angular/di.html

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	<meta charset="UTF-8">
	<title>Document</title>
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<script>
	(function () {

		function extractArgs(fn) { //angular 这里还加了注释、箭头函数的处理
			var args = fn.toString().match(/^[^\(]*\(\s*([^\)]*)\)/m);
			return args[1].split(',');
		}

		function createInjector(cache) {
			this.cache = cache;

		}

		createInjector.prototype = {
			invoke: function (fn, self) {
				argsString = extractArgs(fn);
				args = [];
				argsString.forEach(function (val) {
					args.push(this.cache[val.trim()]);
				}, this);
				return fn.apply(self, args);
			}
		};

		createInjector.prototype.constructor = createInjector;

		function angular() {
		}

		angular.module = function () {
			modules = {};
			injector = new createInjector(modules);
			return {
				injector: injector,
				factory: function (name, fn) {
					modules[name.trim()] = this.injector.invoke(fn);
					return this;
				}
			}
		};

		window.angular = angular;

	})();


	angular.module()
			.factory("minus", function () {
				return function (a, b) {
					return a - b
				}
			})
			.factory("plus", function () {
				return function (a, b) {
					return a + b
				}
			})
			.factory("complex", function (minus, plus) {
				return function (a, b) {
					return minus(a, b) + plus(a, b)
				}
			})
			.injector.invoke(function (minus, plus, complex) { //angular 没有这个属性，为了展示方便这样写
		console.log(minus(3, 1));
		console.log(plus(3, 1));
		console.log(complex(3, 1));
	});
</script>
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