AngularJS 开始入门
快速入门
为什么要用AngularJS?
HTML非常适合于声明静态的文档,但是当我们试图使用它在web应用程序中声明动态视图时,它显得力不从心。AngularJS能为您的应用程序扩展HTML的词汇。由此产生的环境非常具有有表现力、可读性强、快速发展。
替代选择
其他处理HTML的缺点的框架要么是抽象出HTML、CSS、和/或JavaScript,要么为操纵DOM提供一个必要的方式。它们都不能解决一个根本问题,即HTML不是为动态视图设计的。
可扩展性
AngularJS是用来构建框架的工具集,很适全于你的应用程序开发。它完全可扩展,而且与别的库协作得很好。每个功能可以被修改或替代,以适合你的独一无二的开发工作流以及功能需要。继续阅读以弄懂为何。
The Basics
index.html
<!doctype html>
<html ng-app>
<head>
<script src="https://atts.w3cschool.cn/attachments/image/wk/angularjs/angular.min.js"></script>
</head>
<body>
<div>
<label>Name:</label>
<input type="text" ng-model="yourName" placeholder="Enter a name here">
<hr>
<h1>Hello {{yourName}}!</h1>
</div>
</body>
</html>
添加一些控件
数据绑定
数据绑定是每当模型改变时更新视图的自动方法,当视图改变时,同样也会更新模型。这非常棒,因为从你需要担心的列表中它减去了DOM操纵。
控件
控件是DOM元素后面的行为。AngularJS让你能够用一个干净可读的形式表达行为,不需要更新DOM的通常样板、注册回调或者观察模型变化。
扁平的JavaScript
与别的框架不同,不需要为包装访问器方法中的模型,而继承私有类型。Angular模型是扁平的旧式JavaScript对象。这使你的代码容易读取、容易维护、可重用,还不需要样板。
index.html
<!doctype html>
<html ng-app="todoApp">
<head>
<script src="https://atts.w3cschool.cn/attachments/image/wk/angularjs/angular.min.js"></script>
<script src="todo.js"></script>
<link rel="stylesheet" href="todo.css">
</head>
<body>
<h2>Todo</h2>
<div ng-controller="TodoListController as todoList">
<span>{{todoList.remaining()}} of {{todoList.todos.length}} remaining</span>
[ <a href="" ng-click="todoList.archive()">archive</a> ]
<ul class="unstyled">
<li ng-repeat="todo in todoList.todos">
<input type="checkbox" ng-model="todo.done">
<span class="done-{{todo.done}}">{{todo.text}}</span>
</li>
</ul>
<form ng-submit="todoList.addTodo()">
<input type="text" ng-model="todoList.todoText" size="30"
placeholder="add new todo here">
<input class="btn-primary" type="submit" value="add">
</form>
</div>
</body>
</html>
todo.js
angular.module('todoApp', [])
.controller('TodoListController', function() {
var todoList = this;
todoList.todos = [
{text:'learn angular', done:true},
{text:'build an angular app', done:false}];
todoList.addTodo = function() {
todoList.todos.push({text:todoList.todoText, done:false});
todoList.todoText = '';
};
todoList.remaining = function() {
var count = 0;
angular.forEach(todoList.todos, function(todo) {
count += todo.done ? 0 : 1;
});
return count;
};
todoList.archive = function() {
var oldTodos = todoList.todos;
todoList.todos = [];
angular.forEach(oldTodos, function(todo) {
if (!todo.done) todoList.todos.push(todo);
});
};
});
todo.css
.done-true {
text-decoration: line-through;
color: grey;
}
后端连接
深链接
一个深链接反应了用户在应用中的哪个位置,这很有用,所以用户可以把它存为书签以及电子邮件链接,以在应用内部定位它。往返旅行的应用程序会自动获得这个功能,但Ajax应用程序按其性质不会。AngularJS结合了深链接以及类似桌面应用程序的行为的优点。
表单验证
客户端表单验证是完美的用户体验的一个重要的部分。AngularJS使你能够声明表单的有效性规则,而不需要书写JavaScript代码。从而事半功倍。
服务器通信
AngularJS提供了内建的建在在XHR的顶层的服务,以及多种多样的使用第三方库的其它后端。通过处理异步返回的数据,Promise进一步简化了您的代码。在这个示例中,我们使用AngularFire库以把一个Firebase后端接通到一个简单的Angular应用上。
index.html
<!doctype html>
<html ng-app="project">
<head>
<script src="/attachments/image/wk/angularjs/angular.min.js"></script>
<script src="/attachments/image/wk/angularjs/angular-resource.min.js">
</script>
<script src="/attachments/image/wk/angularjs/angular-route.min.js">
</script>
<script src="/attachments/image/wk/angularjs/firebase.js"></script>
<script src="/attachments/image/wk/angularjs/angularfire.min.js"></script>
<link rel="stylesheet" href="bootstrap.css">
<script src="project.js"></script>
</head>
<body>
<h2>JavaScript Projects</h2>
<div ng-view></div>
</body>
</html>
bootstrap.css
// Uncomment this in Plunker or JSFiddle: @import '//netdna.bootstrapcdn.com/twitter-bootstrap/2.0.4/css/bootstrap-combined.min.css';
project.js
angular.module('project', ['ngRoute', 'firebase'])
.value('fbURL', 'https://ng-projects-list.firebaseio.com/')
.service('fbRef', function(fbURL) {
return new Firebase(fbURL)
})
.service('fbAuth', function($q, $firebase, $firebaseAuth, fbRef) {
var auth;
return function () {
if (auth) return $q.when(auth);
var authObj = $firebaseAuth(fbRef);
if (authObj.$getAuth()) {
return $q.when(auth = authObj.$getAuth());
}
var deferred = $q.defer();
authObj.$authAnonymously().then(function(authData) {
auth = authData;
deferred.resolve(authData);
});
return deferred.promise;
}
})
.service('Projects', function($q, $firebase, fbRef, fbAuth) {
var self = this;
this.fetch = function () {
if (this.projects) return $q.when(this.projects);
return fbAuth().then(function(auth) {
var deferred = $q.defer();
var ref = fbRef.child('projects-fresh/' + auth.auth.uid);
var $projects = $firebase(ref);
ref.on('value', function(snapshot) {
if (snapshot.val() === null) {
$projects.$set(window.projectsArray);
}
self.projects = $projects.$asArray();
deferred.resolve(self.projects);
});
//Remove projects list when no longer needed.
ref.onDisconnect().remove();
return deferred.promise;
});
};
})
.config(function($routeProvider) {
var resolveProjects = {
projects: function (Projects) {
return Projects.fetch();
}
};
$routeProvider
.when('/', {
controller:'ProjectListController as projectList',
templateUrl:'list.html',
resolve: resolveProjects
})
.when('/edit/:projectId', {
controller:'EditProjectController as editProject',
templateUrl:'detail.html',
resolve: resolveProjects
})
.when('/new', {
controller:'NewProjectController as editProject',
templateUrl:'detail.html',
resolve: resolveProjects
})
.otherwise({
redirectTo:'/'
});
})
.controller('ProjectListController', function(projects) {
var projectList = this;
projectList.projects = projects;
})
.controller('NewProjectController', function($location, projects) {
var editProject = this;
editProject.save = function() {
projects.$add(editProject.project).then(function(data) {
$location.path('/');
});
};
})
.controller('EditProjectController',
function($location, $routeParams, projects) {
var editProject = this;
var projectId = $routeParams.projectId,
projectIndex;
editProject.projects = projects;
projectIndex = editProject.projects.$indexFor(projectId);
editProject.project = editProject.projects[projectIndex];
editProject.destroy = function() {
editProject.projects.$remove(editProject.project).then(function(data) {
$location.path('/');
});
};
editProject.save = function() {
editProject.projects.$save(editProject.project).then(function(data) {
$location.path('/');
});
};
});
list.html
<input type="text" ng-model="projectList.search" class="search-query" id="projects_search"
placeholder="Search">
<table>
<thead>
<tr>
<th>Project</th>
<th>Description</th>
<th><a href="#/new"><i class="icon-plus-sign"></i></a></th>
</tr>
</thead>
<tbody>
<tr ng-repeat="project in projectList.projects | filter:projectList.search | orderBy:'name'">
<td><a ng-href="{{project.site}}" target="_blank">{{project.name}}</a></td>
<td>{{project.description}}</td>
<td>
<a ng-href="#/edit/{{project.$id}}"><i class="icon-pencil"></i></a>
</td>
</tr>
</tbody>
</table>
detail.html
<form name="myForm">
<div class="control-group" ng-class="{error: myForm.name.$invalid && !myForm.name.$pristine}">
<label>Name</label>
<input type="text" name="name" ng-model="editProject.project.name" required>
<span ng-show="myForm.name.$error.required && !myForm.name.$pristine" class="help-inline">
Required {{myForm.name.$pristine}}</span>
</div>
<div class="control-group" ng-class="{error: myForm.site.$invalid && !myForm.site.$pristine}">
<label>Website</label>
<input type="url" name="site" ng-model="editProject.project.site" required>
<span ng-show="myForm.site.$error.required && !myForm.site.$pristine" class="help-inline">
Required</span>
<span ng-show="myForm.site.$error.url" class="help-inline">
Not a URL</span>
</div>
<label>Description</label>
<textarea name="description" ng-model="editProject.project.description"></textarea>
<br>
<a href="#/" class="btn">Cancel</a>
<button ng-click="editProject.save()" ng-disabled="myForm.$invalid"
class="btn btn-primary">Save</button>
<button ng-click="editProject.destroy()"
ng-show="editProject.project.$id" class="btn btn-danger">Delete</button>
</form>
创建组件
指令
指令是一个独有而且强大的功能,只在Angular中可用。指令使你能够发明新的HTML句法、专针对于你的应用程序。
可重用的组件
我们使用指令以创建可重复使用的组件。组件允许你隐藏复杂的DOM结构、CSS以及行为。这使你能够专注于应用程序要做什么,或者单独的应用程序看起来如何。
本地化
严肃的应用程序的一个重要组成部分是本地化。AngularJS的本地探知筛选器以及阻塞指令使你能够建立屏蔽,使你的应用程序在所有的地方都可用。
index.html
<!doctype html>
<html ng-app="app">
<head>
<script src="https://atts.w3cschool.cn/attachments/image/wk/angularjs/angular.min.js"></script>
<script src="components.js"></script>
<script src="app.js"></script>
<link rel="stylesheet" href="bootstrap.css">
</head>
<body>
<tabs>
<pane title="Localization">
Date: {{ '2012-04-01' | date:'fullDate' }} <br>
Currency: {{ 123456 | currency }} <br>
Number: {{ 98765.4321 | number }} <br>
</pane>
<pane title="Pluralization">
<div ng-controller="BeerCounter">
<div ng-repeat="beerCount in beers">
<ng-pluralize count="beerCount" when="beerForms"></ng-pluralize>
</div>
</div>
</pane>
</tabs>
</body>
</html>
components.js
angular.module('components', [])
.directive('tabs', function() {
return {
restrict: 'E',
transclude: true,
scope: {},
controller: function($scope, $element) {
var panes = $scope.panes = [];
$scope.select = function(pane) {
angular.forEach(panes, function(pane) {
pane.selected = false;
});
pane.selected = true;
}
this.addPane = function(pane) {
if (panes.length == 0) $scope.select(pane);
panes.push(pane);
}
},
template:
'<div class="tabbable">' +
'<ul class="nav nav-tabs">' +
'<li ng-repeat="pane in panes" ng-class="{active:pane.selected}">'+
'<a href="" ng-click="select(pane)">{{pane.title}}</a>' +
'</li>' +
'</ul>' +
'<div class="tab-content" ng-transclude></div>' +
'</div>',
replace: true
};
})
.directive('pane', function() {
return {
require: '^tabs',
restrict: 'E',
transclude: true,
scope: { title: '@' },
link: function(scope, element, attrs, tabsController) {
tabsController.addPane(scope);
},
template:
'<div class="tab-pane" ng-class="{active: selected}" ng-transclude>' +
'</div>',
replace: true
};
})
app.js
angular.module('app', ['components'])
.controller('BeerCounter', function($scope, $locale) {
$scope.beers = [0, 1, 2, 3, 4, 5, 6];
if ($locale.id == 'en-us') {
$scope.beerForms = {
0: 'no beers',
one: '{} beer',
other: '{} beers'
};
} else {
$scope.beerForms = {
0: '?iadne pivo',
one: '{} pivo',
few: '{} pivá',
other: '{} pív'
};
}
});
bootstrap.css
// Uncomment this in Plunker or JSFiddle: @import '//netdna.bootstrapcdn.com/twitter-bootstrap/2.0.4/css/bootstrap-combined.min.css';
可测性内置
可注入
在AngularJS依赖性注入允许你声明式地描述你的应用程序是如何连线的。这意味着你的应用程序不需要main()方法,该方法通常是一个难以维护的大堆杂。依赖性的注入也是AngularJS的一个核心。这意味着任何不适合你的需要的组件可以轻松替换掉。
可测试
AngularJS设计为从根基开始都是可测试的。它鼓励行为与视图分离、用预绑定来模拟、充分利用依赖性注入。它还配备了端到端的场景分流道,它通过理解AngularJS的内部运作机制消除了测试片层分享。
更多建议: