What Is AngularJS?
AngularJS website - https://angularjs.org
AngularJS is a structural framework for dynamic web apps. It lets you use HTML as your template language and lets you extend HTML's syntax to express your application's components clearly and succinctly. AngularJS is a JavaScript-based open-source front-end web framework mainly maintained by Google and by a community of individuals and corporations to address many of the challenges encountered in developing single-page applications. It aims to simplify both the development and the testing of such applications by providing a framework for client-side model–view–controller (MVC) and model–view–viewmodel (MVVM) architectures, along with components commonly used in rich Internet applications.
AngularJS is not a single piece in the overall puzzle of building the client-side of a web application. It handles all of the DOM and AJAX glue code you once wrote by hand and puts it in a well-defined structure. This makes AngularJS opinionated about how a CRUD (Create, Read, Update, Delete) application should be built. But while it is opinionated, it also tries to make sure that its opinion is just a starting point you can easily change. AngularJS comes with the following out-of-the-box:
- Everything you need to build a CRUD app in a cohesive set: Data-binding, basic templating directives, form validation, routing, deep-linking, reusable components and dependency injection.
- Testability story: Unit-testing, end-to-end testing, mocks and test harnesses.
- Seed application with directory layout and test scripts as a starting point.
Why use AngularJS?
1. Empowers with Better User Interface
Angularjs is one of the most popular front-end UI frameworks that provides components that work very well across mobile, web and desktop applications. Angular Material ensures that all modern design principles are adhered to during application development. As User Interface with AngularJS is completely structured, interpreting and manipulating the key components is extremely easy to handle. Learning markups are effortless and indicate that the declarative expression of the application UI will make better sense for the whole team.
2. Simplified MVC Architecture
AngularJS uses MVC architecture which helps developers fast and interactive web application. MVC stands for Model View Controller which means data is maintained by Model and View visualize it while Controller works as a pool to coordinate Model and View.
No doubt that other development frameworks (like PHP) use a similar structure. With these, you had to segregate your application into folders and bind them together by writing your own codes. AngularJS does this for you. Just create the necessary folders, and the rest is taken care of. The model is what maintains the data in the system,
View means displaying the data while the Controller acts as the bridge which connects the Model and the View.
Simply speaking, your website integrates the front-end views displaying the back-end data seamlessly.
The MVVM structure takes this further by interpreting everything into this Model and View structure with the Controller in the hands of the developer.
Post-development – It’s easier for you to control and integrate other multiple changes into the system
3. Injectable
AngularJS comes with dependency injection built-in, which makes testing components much easier, because you can pass in a component's dependencies and stub or mock them as you wish. Components that have their dependencies injected allow them to be easily mocked on a test by test basis, without having to mess with any global variables that could inadvertently affect another test.
4. Two-way data binding
Data-binding in AngularJS apps is the automatic synchronization of data between the model and view components. The way that AngularJS implements data-binding lets you treat the model as the single-source-of-truth in your application. The view is a projection of the model at all times. When the model changes, the view reflects the change, and vice versa.
Most templating systems bind data in only one direction: they merge template and model components together into a view. After the merge occurs, changes to the model or related sections of the view are NOT automatically reflected in the view. Worse, any changes that the user makes to the view are not reflected in the model. This means that the developer has to write code that constantly syncs the view with the model and the model with the view.
AngularJS templates work differently. First the template (which is the uncompiled HTML along with any additionalmarkup or directives) is compiled on the browser. The compilation step produces a live view. Any changes to the view are immediately reflected in the model, and any changes in the model are propagated to the view. The model is the single-source-of-truth for the application state, greatly simplifying the programming model for the developer. You can think of the view as simply an instant projection of your model. Because the view is just a projection of the model, the controller is completely separated from the view and unaware of it. This makes testing a snap because it is easy to test your controller in isolation without the view and the related DOM/browser dependency.
Additional tools for testing AngularJS applications
For testing AngularJS applications there are certain tools that you should use that will make testing much easier to set up and run.
Karma
Karma is a JavaScript command line tool that can be used to spawn a web server which loads your application's source code and executes your tests. You can configure Karma to run against a number of browsers, which is useful for being confident that your application works on all browsers you need to support. Karma is executed on the command line and will display the results of your tests on the command line once they have run in the browser. Karma is a NodeJS application, and should be installed through npm/yarn. Full installation instructions are available on the Karma website.
angular-mocks
AngularJS also provides the ngMock
module, which provides mocking for your tests. This is used to inject and mock AngularJS services within unit tests. In addition, it is able to extend other modules so they are synchronous. Having tests synchronous keeps them much cleaner and easier to work with. One of the most useful parts of ngMock is $httpBackend
, which lets us mock XHR requests in tests, and return sample data instead.
AngularJS Support Status
Any version branch not shown in the following table (e.g. 1.6.x) is no longer being developed.
Version | Status | Comments |
---|---|---|
1.2.x | Security patches only | Last version to provide IE 8 support |
1.7.x | Long Term Support | See Long Term Support section below. |
Long Term Support
On July 1st 2018, AngularJS entered a Long Term Support period for AngularJS.
According to AngularJS developers, all AngularJS applications that work now, will continue to work in the future.All published versions of AngularJS, on npm, bower, CDNs, etc will continue to be available.
AngularJS is now focus exclusively on providing fixes to bugs that satisfy at least one of the following criteria:
- A security flaw is detected in the 1.7.x branch of the framework
- One of the major browsers releases a version that will cause current production applications using AngularJS 1.7.x to stop working
- The jQuery library releases a version that will cause current production applications using AngularJS 1.7.x to stop working.
You can read more about these plans in blog post announcement.
Angular vs AngularJS (Top differences)