@ngdoc overview
@name Developer Guide: Initializing Angular: Automatic Initialization
@description

Angular initializes automatically when you load the angular script into your page, specifying
angular's `ng:autobind` attribute with no arguments:

        <script src="angular.js" ng:autobind>

From a high-level view, this is what happens during angular's automatic initialization process:

1. The browser loads the page, and then runs the angular script.

    The `ng:autobind` attribute tells angular to compile and manage the whole HTML document. The
compilation phase is initiated in the page's `onLoad()` handler. Angular doesn't begin processing
the page until after the page load is complete.

2. Angular finds the root of the HTML document and creates the global variable `angular` in the
global namespace. Everything that angular subsequently creates is bound to fields in this global
object.

3. Angular walks the DOM looking for angular widgets, directives, and markup (such as `ng:init` or
`ng:repeat`). As angular encounters these, it creates child scopes as necessary and attaches them
to the DOM, registers listeners on those scopes, associates any controller functions with their
data and their part of the view, and ultimately constructs a runnable application. The resulting
app features two-way data-binding and a nice separation between data, presentation, and business
logic.

4. For the duration of the application session (while the page is loaded), angular monitors the
state of the application, and updates the view and the data model whenever the state of either one
changes.

For details on how the compiler works, see {@link dev_guide.compiler Angular HTML Compiler}.


## Initialization Options

The reason why `ng:autobind` exists is because angular should not assume that the entire HTML
document should be processed just because the `angular.js` script is included. In order to compile
only a part of the document, specify the ID of the element you want to use for angular's root
element as the value of the `ng:autobind` attribute:

        ng:autobind="angularContent"


## Auto-bootstrap with `#autobind`

In some rare cases you can't define the `ng:` prefix before the script tag's attribute  (for
example,  in some CMS systems). In those situations it is possible to auto-bootstrap angular by
appending `#autobind` to the `<script src=...>` URL, like in this snippet:

<pre>
  <!doctype html>
  <html>
   <head>
    <script type="text/javascript"
            src="http://code.angularjs.org/angular.js#autobind"></script>
   </head>
   <body>
     <div xmlns:ng="http://angularjs.org">
       Hello {{'world'}}!
     </div>
   </body>
  </html>
</pre>

As with `ng:autobind`, you can specify an element id that should be exclusively targeted for
compilation as the value of the `#autobind`, for example: `#autobind=angularContent`.

## Filename Restrictions for Auto-bootstrap

In order for us to find the auto-bootstrap from a script attribute or URL fragment, the value of
the `script` `src` attribute that loads the angular script must match one of these naming
conventions:

- `angular.js`
- `angular-min.js`
- `angular-x.x.x.js`
- `angular-x.x.x.min.js`
- `angular-x.x.x-xxxxxxxx.js` (dev snapshot)
- `angular-x.x.x-xxxxxxxx.min.js` (dev snapshot)
- `angular-bootstrap.js` (used for development of angular)

Optionally, any of the filename formats above can be prepended with a relative or absolute URL that
ends with `/`.

## Global Angular Object

The angular script creates a single global variable `angular` in the global namespace. All angular
APIs are bound to fields of this global object.


## Related Topics

* {@link dev_guide.bootstrap Initializing Angular}
* {@link dev_guide.bootstrap.manual_bootstrap Manual Initialization}

## Related API

{@link api/angular.compile Compiler API}
