Use this directive toauto-bootstrapan AngularJS application. ThengApp
directive designates theroot elementof the application and is typically placed near the root element of the page - e.g. on the<body>
or<html>
tags.
There are a few things to keep in mind when usingngApp
:
- only one AngularJS application can be auto-bootstrapped per HTML document. The first
ngApp
found in the document will be used to define the root element to auto-bootstrap as an application. To run multiple applications in an HTML document you must manually bootstrap them usingangular.bootstrap
instead. - AngularJS applications cannot be nested within each other.
- Do not use a directive that usestransclusionon the same element as
ngApp
. This includes directives such asngIf
,ngInclude
andngView
. Doing this misplaces the app$rootElement
and the app'sinjector,causing animations to stop working and making the injector inaccessible from outside the app.
You can specify anAngularJS moduleto be used as the root module for the application. This module will be loaded into the$injector
when the application is bootstrapped. It should contain the application code needed or have dependencies on other modules that will contain the code. Seeangular.module
for more information.
In the example below if thengApp
directive were not placed on thehtml
element then the document would not be compiled,theAppController
would not be instantiated and the{{a+b}}
would not be resolved to3
.
ngApp
is the easiest,and most common way to bootstrap an application.
Edit in Plunker
<div ng-controller="ngAppDemoController"> I can add: {{a}} + {{b}} = {{ a+b }} </div>
UsingngStrictDi
,you would see something like this:
Edit in Plunker
<div ng-app="ngAppStrictDemo" ng-strict-di> <div ng-controller="GoodController1"> I can add: {{a}} + {{b}} = {{ a+b }} <p>This renders because the controller does not fail to instantiate,by using explicit annotation style (see script.js for details) </p> </div> <div ng-controller="GoodController2"> Name: <input ng-model="name"><br /> Hello,{{name}}! <p>This renders because the controller does not fail to instantiate,by using explicit annotation style (see script.js for details) </p> </div> <div ng-controller="BadController"> I can add: {{a}} + {{b}} = {{ a+b }} <p>The controller could not be instantiated,due to relying on automatic function annotations (which are disabled in strict mode). As such,the content of this section is not interpolated,and there should be an error in your web console. </p> </div> </div>
Directive Info
- This directive executes at priority level 0.
Usage
- as element: (This directive can be used as custom element,but be aware ofIE restrictions).
<ng-app ng-app="angular.Module" [ng-strict-di="boolean"]> ... </ng-app>
- as attribute:
<ANY ng-app="angular.Module" [ng-strict-di="boolean"]> ... </ANY>
Arguments
Param | Type | Details |
---|---|---|
ngApp | angular.Module | an optional applicationmodulename to load. |
ngStrictDi (optional) |
boolean | if this attribute is present on the app element,the injector will be created in "strict-di" mode. This means that the application will fail to invoke functions which do not use explicit function annotation (and are thus unsuitable for minification),as described inthe Dependency Injection guide,and useful debugging info will assist in tracking down the root of these bugs. |