HTML is great for declaring static documents, but it falters when we try to use it for declaring dynamic views in web-applications. AngularJS lets you extend HTML vocabulary for your application. The resulting environment is extraordinarily expressive, readable, and quick to develop.
AngularJS is a toolset for building the framework most suited to your application development. It is fully extensible and works well with other libraries. Every feature can be modified or replaced to suit your unique development workflow and feature needs. Read on to find out how.
Add Some Control
Data-binding is an automatic way of updating the view whenever the model changes, as well as updating the model whenever the view changes. This is awesome because it eliminates DOM manipulation from the list of things you have to worry about.
Controllers are the behavior behind the DOM elements. AngularJS lets you express the behavior in a clean readable form without the usual boilerplate of updating the DOM, registering callbacks or watching model changes.
Directives are a unique and powerful feature available in AngularJS. Directives let you invent new HTML syntax, specific to your application.
We use directives to create reusable components. A component allows you to hide complex DOM structure, CSS, and behavior. This lets you focus either on what the application does or how the application looks separately.
An important part of serious apps is localization. AngularJS's locale aware filters and stemming directives give you building blocks to make your application available in all locales.
How it works
Navigation, Forms and Backends
A deep link reflects where the user is in the app. This is useful so users can bookmark and email links to locations within the app. Round trip apps get this automatically, but AJAX apps by their nature do not. AngularJS combines the benefits of deep linking with desktop app-like behavior.
AngularJS provides built-in services on top of XHR as well as various other backends using third party libraries. Promises further simplify your code by handling asynchronous return of data.
The dependency injection in AngularJS allows you to declaratively describe how your application is wired. This means that your application needs no main() method which is usually an unmaintainable mess. Dependency injection is also a core to AngularJS. This means that any component which does not fit your needs can easily be replaced.
AngularJS was designed from ground up to be testable. It encourages behavior-view separation, comes pre-bundled with mocks, and takes full advantage of dependency injection. It also comes with end-to-end scenario runner which eliminates test flakiness by understanding the inner workings of AngularJS.