AngularJS Tutorial（18）from w3school

转载于 2015-08-04 09:31:26 发布 · 550 阅读

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It is time to create a real AngularJS Single Page Application (SPA).

An AngularJS Application Example

You have learned more than enough to create your first AngularJS application:

My Note

Number of characters left: 100

Application Explained

AngularJS Example

< html ng-app= "myNoteApp" >
< script src= "http://ajax.googleapis.com/ajax/libs/angularjs/1.3.14/angular.min.js" > < /script >
< body >

< div ng-controller= "myNoteCtrl" >

< h2 >My Note < /h2 >

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

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

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

< /div >

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

< /body >
< /html >

Try it Yourself »

The application file "myNoteApp.js":

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

The 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":

< html ng-app= "myNoteApp" >

A a <div> in the HTML page is the scope of a controller: ng-controller="myNoteCtrl":

< div ng-controller= "myNoteCtrl" >

An ng-model directive binds a <textarea> to the controller variable message:

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

The two ng-click events invoke the controller functions clear() and save():

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

An ng-bind directive binds the controller function left() to a <span> displaying the characters left:

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

Your application libraries are added to the page (after the library):

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

AngularJS Application Skeleton

Above you have the skeleton (scaffolding) of a real life AngularJS, single page application (SPA).

The <html> element is the "container" for the AngularJS application (ng-app=).

A <div> elements defines the scope of an AngularJS controller (ng-controller=).

You can have many controllers in one application.

An application file (my...App.js) defines the application module code.

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

Summary - How Does it Work?

The ng-app directive is placed at the root element the application.

For single page applications (SPA), the root of the application is often the <html> element.

One or more ng-controller directives define the application controllers. Each controller has its own scope: the HTML element where they were defined.

AngularJS starts automatically on the HTML DOMContentLoaded event. If an ng-app directive is found, AngularJS will load any module named in the directive, and compile the DOM with ng-app as the root of the application.

The root of the application can be the whole page, or a smaller portion of the page. The smaller the portion, the faster the application will compile and execute.