在angular中,controller是一個javascript 函數(type/class),被用作擴展除了root scope在外的angular scope(//www.VeVB.COm/article/91749.htm)的實例。當我們或者angular通過scope.$new API(http://docs.angularjs.org/api/ng.$rootScope.Scope#$new)創建新的child scope時,有一個選項作為方法的參數傳入controller(這裡沒看明白,只知道controller的第一個參數是一個新創建的scope,有綁定parent scope)。這將告訴angular需要聯合controller和新的scope,並且擴展它的行為。
controller可以用作:
1.設置scope對象的初始狀態。
2.增加行為到scope中。
一、 Setting up the initial state of a scope object(設置scope對象的初始狀態)
通常,當我們創建應用的時候,我們需要為angular scope設置初始化狀態。
angular將一個新的scope對象應用到controller構造函數(估計是作為參數傳進去的意思),建立了初始的scope狀態。這意味著angular從不創建controller類型實例(即不對controller的構造函數使用new操作符)。構造函數一直都應用於存在的scope對象。
我們通過創建model屬性,建立了scope的初始狀態。例如:
function GreetingCtrl ($scope) {$scope.greeting = “Hola!”;}
“GreetingCtrl”這個controller創建了一個叫“greeting”的,可以被應用到模版中的model。
二、 Adding Behavior to a Scope Object(在scope object中增加行為)
在angular scope對像上的行為,是以scope方法屬性的形式,供模版、視圖使用。這行為(behavior)可以修改應用的model。
正如指引的model章節(//www.VeVB.COm/article/91777.htm)討論的那樣,任意對象(或者原始的類型)賦值到scope中,成為了model屬性。任何附加到scope中的function,對於模版視圖來說都是可用的,可以通過angular expression調用,也可以通過ng event handler directive調用(如ngClick)。
三、 Using Controllers Correctly
一般而言,controller不應該嘗試做太多的事情。它應該僅僅包含單個視圖所需要的業務邏輯(還有點沒轉過彎了,一直認為Controller就是個做轉發的……)。
保持Controller的簡單性,常見辦法是抽出那些不屬於controller的工作到service中,在controller通過依賴注入來使用這些service。這些東西會在嚮導的Dependency Injection Services章節中討論。
不要在Controller中做以下的事情:
四、 Associating Controllers with Angular Scope Objects
我們可以顯式地通過scope.$new關聯controller和scope對象,或者隱式地通過ngController directive(http://docs.angularjs.org/api/ng.directive:ngController)或者$route service(http://docs.angularjs.org/api/ng.$route)。
1. Controller 構造函數和方法的Example
為了說明controller組件是如何在angular中工作的,讓我們使用以下組件創建一個小應用:
在我們的模版裡面的消息,包含一個到spice model的綁定,默認設置為”very”。根據被單擊按鈕,將spice model的值設置為”chili”或者” jalapeño”,消息會被數據綁定自動更新。
<!DOCTYPE html><html ng-app><head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"/> <title>spicy-controller</title> <meta content="IE=edge,chrome=1" http-equiv="X-UA-Compatible"> <style type="text/css"> .ng-cloak { display: none; } </style></head><body> <div ng-controller="SpicyCtrl"> <button ng-click="chiliSpicy()">Chili</button> <button ng-click="jalapenoSpicy('jalapeño')">Jalapeño</button> <p>The food is {{spice}} spicy!</p> </div> <script src="../angular-1.0.1.js" type="text/javascript"></script> <script type="text/javascript"> function SpicyCtrl($scope) { $scope.spice = "very"; $scope.chiliSpicy = function() { $scope.spice = "chili"; }; $scope.jalapenoSpicy = function(val) { this.spice = val; }; } </script></body></html>在上面例子中需要注意的東東:
controller方法可以帶參數的,正如下面例子所示:
<!DOCTYPE html><html ng-app><head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"/> <title>controller-method-aruments</title> <meta content="IE=edge,chrome=1" http-equiv="X-UA-Compatible"> <style type="text/css"> .ng-cloak { display: none; } </style></head><body> <div ng-controller="SpicyCtrl"> <input ng-model="customSpice" value="wasabi"/> <button ng-click="spicy(customSpice)">customSpice</button> <br/> <button ng-click="spicy('Chili')">Chili</button> <p>The food is {{spice}} spicy!</p> </div> <script src="../angular-1.0.1.js" type="text/javascript"></script> <script type="text/javascript"> function SpicyCtrl($scope) { $scope.spice = "very"; $scope.spicy = function(spice) { $scope.spice = spice; }; } </script></body></html>注意那個SpicyCtrl controller現在只定義了一個有一個參數”spice”、叫”spicy”的方法。 template可以引用controller方法並為它傳遞常量字符串或model值。
Controller繼承在angular是基於scope繼承的。讓我們看看下面的例子:
<!DOCTYPE html><html ng-app><head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"/> <title>controller-inheritance</title> <meta content="IE=edge,chrome=1" http-equiv="X-UA-Compatible"> <style type="text/css"> .ng-cloak { display: none; } </style></head><body> <div ng-controller="MainCtrl"> <p>Good {{timeOfDay}}, {{name}}!</p> <div ng-controller="ChildCtrl"> <p>Good {{timeOfDay}}, {{name}}!</p> <p ng-controller="BabyCtrl">Good {{timeOfDay}}, {{name}}!</p> </div> </div> <script src="../angular-1.0.1.js" type="text/javascript"></script> <script type="text/javascript"> function MainCtrl($scope) { $scope.timeOfDay = 'Main時間'; $scope.name = 'Main名稱'; } function ChildCtrl($scope) { $scope.name = 'Child名稱'; } function BabyCtrl($scope) { $scope.timeOfDay = 'Baby時間'; $scope.name = 'Baby名稱'; } </script></body></html>注意我們如何嵌套3個ngController directive到模版中的。為了我們的視圖,這模版結構將會導致4個scope被創建:
繼承的工作,在controller和model中是一樣的。所以我們前一個例子中,所有model可以通過controller被重寫。
注意:在兩個Controller之間標準原型繼承不是如我們所想地那樣工作的,因為正如我們之前提到的,controller不是通過angular直接初始化的,但相反地,apply了那個scope對象。 (controllers are not instantiated directly by angular, but rather are applied to the scope object,這裡跟之前一樣,我還是沒理解。)
五、 Testing Controller
雖然有很多方法去測試controller,最好的公約之一,如下面所示,需要注入$rootScope和$controller。 (測試需要配合jasmine.js)
<!DOCTYPE html><html ng-app><head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"/> <title>controller-test</title> <meta content="IE=edge,chrome=1" http-equiv="X-UA-Compatible"> <link rel="stylesheet" href="../jasmine.css"> <style type="text/css"> .ng-cloak { display: none; } </style></head><body><script src="../angular-1.0.1.js" type="text/javascript"></script><script src="../angular-scenario-1.0.1.js" type="text/javascript"></script><script src="../jasmine.js" type="text/javascript"></script><script src="../jasmine-html.js" type="text/javascript"></script><script src="../angular-mocks-1.0.1.js" type="text/javascript"></script><script type="text/javascript"> function MyController($scope) { $scope.spices = [ {"name":"pasilla", "spiciness":"mild"}, {"name":"jalapeno", "spiceiness":"hot hot hot!"}, {"name":"habanero", "spiceness":"LAVA HOT!!"} ]; $scope.spice = "habanero"; } describe("MyController function", function () { describe("MyController", function () { var scope; beforeEach(inject(function ($rootScope, $controller) { scope = $rootScope.$new(); var ctrl = $controller(MyController, {$scope:scope}); })); it('should create "cpices" model with 3 spices', function () { expect(scope.spices.length).toBe(3); }); it('should set the default value of spice', function () { expect(scope.spice).toBe("habanero"); }); }); }); (function () { var jasmineEnv = jasmine.getEnv(); jasmineEnv.updateInterval = 1000; var trivialReporter = new jasmine.TrivialReporter(); jasmineEnv.addReporter(trivialReporter); jasmineEnv.specFilter = function (spec) { return trivialReporter.specFilter(spec); }; var currentWindowOnload = window.onload; window.onload = function () { if (currentWindowOnload) { currentWindowOnload(); } execJasmine(); }; function execJasmine() { jasmineEnv.execute(); } })();</script></body></html>如果我們需要測試嵌套的controller,我們需要在test中創建與DOM裡面相同的scope繼承關係。
<!DOCTYPE html><html ng-app><head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"/> <title>controller-test</title> <meta content="IE=edge,chrome=1" http-equiv="X-UA-Compatible"> <link rel="stylesheet" href="../jasmine.css"> <style type="text/css"> .ng-cloak { display: none; } </style></head><body><script src="../angular-1.0.1.js" type="text/javascript"></script><script src="../angular-scenario-1.0.1.js" type="text/javascript"></script><script src="../jasmine.js" type="text/javascript"></script><script src="../jasmine-html.js" type="text/javascript"></script><script src="../angular-mocks-1.0.1.js" type="text/javascript"></script><script type="text/javascript"> function MainCtrl($scope) { $scope.timeOfDay = 'Main時間'; $scope.name = 'Main名稱'; } function ChildCtrl($scope) { $scope.name = 'Child名稱'; } function BabyCtrl($scope) { $scope.timeOfDay = 'Baby時間'; $scope.name = 'Baby名稱'; } describe("MyController", function () { var mainScope,childScope,babyScope; beforeEach(inject(function ($rootScope, $controller) { mainScope = $rootScope.$new(); var mainCtrl = $controller(MainCtrl, {$scope:mainScope}); childScope = mainScope.$new(); var childCtrl = $controller(ChildCtrl, {$scope:childScope}); babyScope = childScope.$new(); var babyCtrl = $controller(BabyCtrl, {$scope:babyScope}); })); it('should have over and selected', function () { expect(mainScope.timeOfDay).toBe("Main時間"); expect(mainScope.name).toBe("Main名稱"); expect(childScope.timeOfDay).toBe("Main時間"); expect(childScope.name).toBe("Child名稱"); expect(babyScope.timeOfDay).toBe("Baby時間"); expect(babyScope.name).toBe("Baby名稱"); }); }); (function () { var jasmineEnv = jasmine.getEnv(); jasmineEnv.updateInterval = 1000; var trivialReporter = new jasmine.TrivialReporter(); jasmineEnv.addReporter(trivialReporter); jasmineEnv.specFilter = function (spec) { return trivialReporter.specFilter(spec); }; var currentWindowOnload = window.onload; window.onload = function () { if (currentWindowOnload) { currentWindowOnload(); } execJasmine(); }; function execJasmine() { jasmineEnv.execute(); } })();</script></body></html>以上就是關於AngularJs Understanding the Controller Component的資料整理,後續繼續補充相關資料,謝謝大家的支持!