AngularJS application

Now it’s time to create a real AngularJS single page web application (SPA).

AngularJS Application Example

You have learned enough about AngularJS and now you can start creating your first AngularJS application:

Application explanation

Example

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<script src="//cdn.bootcss.com/angular.js/1.4.6/angular-animate.min.js"></script>
</head>
<body ng-app="myNoteApp" ng-controller="myNoteCtrl">

<h2>我的笔记</h2>


<textarea ng-model="message" cols="40" rows="10"></textarea>

<p>
<button ng-click="save()">保存</button>
<button ng-click="clear()">清除</button>
</p>

<p>剩余字数: <span ng-bind="left()"></span></p>

<script src="myNoteApp.js"></script>
<script src="myNoteCtrl.js"></script>

</body>
</html>

Running example »

Click the "Run Instance" button to view the online instance

Application file "myNoteApp.js":

var app = angular.module( "myNoteApp", []);

Controller file "myNoteCtrl.js":

app.controller("myNoteCtrl", function($scope) {
$scope.message = "";
$scope.left = function() {return 100 - $scope.message.length;};
$scope.clear = function() {$scope.message = "";};
$scope.save = function() {alert("Note Saved");};
});

< The html> element is the container of the AngularJS application: ng-app="myNoteApp":

##<div> is the controller in the HTML page: ng-controller="

myNoteCtrl" scope:

##ng-model

directive binds <textarea> to the controller variable message:

textarea ng-model="message" cols="40" rows="10"></textarea>

Two ng-click events call the controller functions clear() and save():

<button ng-click="save()">Save</button>
<button ng-click=" clear()">Clear</button>

ng-bind The instruction binds the controller function left() to <span>, which is used to display the remaining characters:

Number of characters left: <span ng-bind="left()"></span>

The application library file needs to be loaded in AngularJs before it can be executed:

< ;script src="myNoteApp.js"></ script>
<script src="myNoteCtrl.js"></script>

AngularJS application architecture

The above example is a complete AngularJS single page web application (single page web application, SPA). The

<html> element contains the AngularJS application (ng-app=). The

<div> element defines the scope of the AngularJS controller (ng-controller=).

An application can have many controllers.

The application file (my...App.js) defines the application model code.

One or more controller files (my...Ctrl.js) define the controller code.

Summary - How does it work?

ng-app directive is located under the root element of the application.

For a single page web application (SPA), the root of the application is usually <html> element.

One or more ng-controller directives define the application's controller. Each controller has its own scope: defined HTML element.

AngularJS automatically starts in the HTML DOMContentLoaded event. if found ng-app directive, AngularJS loads the module in the directive and compiles ng-app as the root of the application.

The root of the application can be the entire page, or a small part of the page. If it is a small part, it will compile and execute faster.