启动过程(v1.3.9)###
步骤一
用自执行函数的形式让整个代码在加载完成之后立即执行
inangular.js
Line6(function(window, document, undefined)
在window上暴露一个唯一的全局对象angular,Line250
angular = window.angular || (window.angular = {})
获得其它工具模块 Line 2129
function publishExternalAPI(angular) { extend(angular, { 'bootstrap': bootstrap, 'copy': copy, 'extend': extend, 'equals': equals, 'element': jqLite, 'forEach': forEach, 'injector': createInjector, 'noop': noop, 'bind': bind, .....
我们来看看angular全局对象都有什么东西
接着,我们使用全局对象中的isFunction 来遍历一下angular全局对象上的属性,函数
var counter = 0; for (var p in angular) { counter++; if (angular.isFunction(angular[p])) { console.log("function->" + p); } else { console.log("property-->" + p + "-->" + angular[p]); } } console.log(counter);
有两个property,其它都是function
我们再来看看injector里都有什么
/** * angular.injector(); */ var injector = angular.injector(); console.log(injector);
一共有5个方法
annotate:分析函数签名(不要new的原因)
步骤二
检查是不是多次导入Angular:window.angular.bootstrap(通过检查指定的元素上是否已经存在injector进行判断)
in
angular.js
line 26041
if (window.angular.bootstrap) { //AngularJS is already loaded, so we can return here... console.log('WARNING: Tried to load angular more than once.'); return; }
angular的三种启动方式
自动启动
Angular会自动的找到
ng-app
,将它作为启动点,自动启动<!DOCTYPE html> <html ng-app="myModule"> <head> <title>New Page</title> <meta charset="utf-8" /> <script type="text/javascript" class="lazyload" src="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAANSURBVBhXYzh8+PB/AAffA0nNPuCLAAAAAElFTkSuQmCC" data-original="../../vendor/bower_components/angular/angular.min.js"></script> <script type="text/javascript" class="lazyload" src="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAANSURBVBhXYzh8+PB/AAffA0nNPuCLAAAAAElFTkSuQmCC" data-original="./02.boot1.js"></script> </head> <body> <div ng-controller="MyCtrl"> <span>{{Name}}</span> </div> </body> </html>js var myModule = angular.module("myModule", []); myModule.controller('MyCtrl', ['$scope', function($scope) { $scope.Name = "Puppet"; } ]);
手动启动
在没有ng-app的情况下,只需要在js中添加一段注册代码即可 <body> <div ng-controller="MyCtrl"> <span>{{Name}}</span> </div> </body>
js
var myModule = angular.module("myModule", []); myModule.controller('MyCtrl', ['$scope', function($scope) { $scope.Name = "Puppet"; } ]); /** * 这里要用ready函数等待文档初始化完成 */ angular.element(document).ready(function() { angular.bootstrap(document, ['myModule']); });
多个ng-app
ng中,angular的ng-app是无法嵌套使用的,在不嵌套的情况下有多个ng-app,他默认只会启动第一个ng-app,第二个第三个需要手动启动(注意,不要手动启动第一个,虽然可以运行,但会抛异常)
<body> <div id="app1" ng-app="myModule1"> <div ng-controller="MyCtrl"> <span>{{Name}}</span> </div> </div> <div id="app2" ng-app="myModule2"> <div ng-controller="MyCtrl"> <span>{{Name}}</span> </div> </div> </body>
js
/** * 第一个APP * @type {[type]} */ var myModule1 = angular.module("myModule1", []); myModule1.controller('MyCtrl', ['$scope', function($scope) { $scope.Name = "Puppet"; } ]); // angular.element(document).ready(function() { // angular.bootstrap(app1, ['MyModule1']); // }); /** * 第二个APP * @type {[type]} */ var myModule2 = angular.module("myModule2", []); myModule2.controller('MyCtrl', ['$scope', function($scope) { $scope.Name = "Vincent"; } ]); angular.element(document).ready(function() { angular.bootstrap(app2, ['myModule2']); });
步骤三
尝试绑定jQuery,如果发现导入了jQuery ,则使用导入的jQuery,否则,使用Angular自己封装的JQLite
in angular.js
line 1521:
bindJQuery();
in angular.js
line 1534:
jQuery = window.jQuery;if (jQuery && jQuery.fn.on) { jqLite = jQuery; extend(jQuery.fn, { scope: JQLitePrototype.scope, isolateScope: JQLitePrototype.isolateScope, controller: JQLitePrototype.controller, injector: JQLitePrototype.injector, inheritedData: JQLitePrototype.inheritedData });
测试
<html ng-app="myModule"><body> <div> <div ng-controller="MyCtrl"> <span>{{Name}}</span> </div> </div></body></html>
js
var myModule = angular.module("myModule", []); myModule.controller('MyCtrl', ['$scope', function($scope) { $scope.Name = "Puppet"; } ]);
查看执行流程
步骤四
发布ng提供的API
in angular.js
line 2162 : publishExternalAPI(angular);
//构建模块加载器angularModule = setupModuleLoader(window); try { angularModule('ngLocale'); } catch (e) { angularModule('ngLocale', []).provider('$locale', $LocaleProvider); }
模块加载器的实现原理
in angular.js
function setupModuleLoader(window)
function setupModuleLoader(window) { var $injectorMinErr = minErr('$injector'); var ngMinErr = minErr('ng'); function ensure(obj, name, factory){ return obj[name] || (obj[name] = factory()); } var angular = ensure(window, 'angular', Object); // We need to expose `angular.$$minErr` to modules such as `ngResource` that reference it during bootstrap angular.$$minErr= angular.$ $minErr || minErr; //把module方法放到angular的全局对象上,ensure就是一个属性拷贝的过程return ensure(angular, 'module', function(){ //模块缓存 var modules = {}; }
把工具函数给载到模块里
return function module(name, requires, configFn) { ...... }
查看模块里所包含的内容
<!DOCTYPE html><html ng-app="myModule"></html>
JS
/** * 定义模块 */var myModule = angular.module("myModule", []);/** * 从debug的过程可以看到,angular中的“模块”只是一个闭包空间(或者叫命名空间) * 所有模块都被注册在modules这个对象上 */console.log(myModule);
查看控制台
构建内置模块ng
in angular.js
line 2169 publishExternalAPI(angular)
angularModule('ng', ['ngLocale'], ['$provide', function ngModule($provide) { // $ $sanitizeUriProvider needs to be before $compileProvider as it is used by it. $provide.provider({ $ $sanitizeUri: $$SanitizeUriProvider }); $provide.provider('$compile', $CompileProvider). directive({ a: htmlAnchorDirective, input: inputDirective, ......
加载了所有内置的directive,provider.注册ng内核Provider:两个最重要的$parser
和 $rootScope
总结
工具函数拷贝到angular全局对象上;
调用setupModuleLoader方法创建模块定义和加载工具(挂在全局对象window.angular上);
构建内置模块ng;
创建ng内置的directive和provider;
两个重要的provider:$parse 和 $rootScope;
步骤五
初始化Angular - 查找Ng-app
jqLite(document).ready(function() { angularInit(document, bootstrap); });
bootstrap
创建injector,拉起内核和启动模块,调用compile服务
(一个ng-app只有一个injector)
in angular.js
line 1415
function bootstrap(element, modules, config){ .... }
作者:易sense
链接:https://www.jianshu.com/p/d805f599fda5
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