Introduction to AngularJS

History of AngularJS

Angular JS was created in 2009 as a Google project. Misko Hevery and Adam Abrons created it. Google still keeps an involved community for Angular. With AngularJS, static HTML sites could be made interactive, quickly increasing their popularity and support. ReactJS and VueJS were challenging rivals to Angular 1. Therefore, Google finally reworked it and changed it to TypeScript as the alternate language. The choice to move to TypeScript was taken to eliminate JavaScript's flaws. Angular 4, 5, 6, and 7 emerged after Angular 2. 

Why Use AngularJS

Moving forward in this Angular JS tutorial, let’s see why to learn Angular JS. Angular prioritizes the developer experience. The fact that AngularJS offers single-page applications is the key reason to learn JS. Nobody wants to wait around for an application or website to load completely. The core team of Angular is working tirelessly to make it a more user-friendly yet potent product as it becomes more and more popular among developers and newcomers.

Given the industry, Angular is quite skill-demanding because most organizations have migrated their projects into it and anticipate using it for enterprise products soon. If we closely examine market attitudes, we can see that Angular is one of the most in-demand abilities. If a candidate possesses this expertise, recruiters and IT organizations will be on the lookout for them because Angular is a well-known full-featured framework for single-page applications (SPAs).

Since Angular has its routing system, we can load the relevant portions of the application at that moment and display the area the user is interested in viewing.

Single-page applications load pre-existing HTML pages into the browser and dynamically change the contents based on user input. Angular JS offers all the advantages. AngularJS's integrated dependency injection framework greatly simplifies unit testing. Instead of looking for dependencies, developers just need to enter them as parameters.

Different Versions of AngularJS

AngularJS alone includes the initial version of Angular. It was published on October 10, 2010. The name "Angular" refers to all the versions that followed AngularJS (Angular 1), including Angular 2, Angular 4, Angular 5, and now Angular 6. It has the most up-to-date and perfect framework for creating dynamic, responsive web applications.

Numerous updates and bug fixes from version 4 are included in Angular 5 and several new parts. Angular 5 is very faster, with better loading and performance times.

The most recent is Angular 6. The Google team claims that this is a strong version more concerned with the toolchain than the basic framework, making it simpler to work fast with Angular in the future.

With Angular 6, a new CLI command called "ng update <package>" was released. Using its knowledge of Angular, it scans package.json and suggests improvements for your application.

Let us see each version of Angular JS in detail.

AngularJS

AngularJS, sometimes called Angular 1, is an open-source front-end web application framework built on JavaScript. With a framework for the client-side model-view-controller (MVC) and model-view-viewmodel (MVVM) architectures, it was developed to make building and testing applications easier.

Also Read, Front End Web Development

Angular 2

Angular 2 is regarded as a different framework from AngularJS because it is a complete rebuild of the earlier version. It employs a component-based methodology, has more sophisticated functionality, and has cleaner code.

Angular 4

Angular 4 was launched at the end of 2016, skipping version 3. It was done to prevent confusion brought on by the router package version's incompatibility, which was already being distributed as v3.3.0. Naturally, Angular 4 adds new functionalities, including the more effective and approachable HttpClient module for building HTTP requests. In March 2017, the complete version was made available.

Angular 5

In November 2017, Angular 5 was released. Compared to earlier versions of Angular, some significant modifications have also been introduced. You can use the build optimizer by default in this version, thanks to a build optimizer that was generated with the Angular CLI. In addition, Angular Universal State Transfer is available, which supports DOM and API.

Angular 6 

On May 4, 2018, Angular 6 was released. A significant update places more emphasis on the toolchain and less on the underlying framework. Some new features in this version are Tree Shakeable Providers, Angular Elements, Component Dev Kit, Angular Material Starter Components, and Library support.

Angular 7

The release of Angular 7 occurred on October 18, 2018. Updates on CDK, Angular Material Virtual Scrolling, and Application Performance were given. Additionally, it offers Support for Content Projection Using Web Standards for Custom Elements, Improved Accessibility of Selects, and Dependency Updates for Typescript 3.1, RxJS 6.3, and Node 10.

Angular 8

Angular 8 was a significant update that was released in May 2019. It added significant new features like network robots, dynamic imports for lazy routes, TypeScript 3.4, and Angular Ivy support as options previews and differential loading for entire application code.

Angular 9

In February 2020, Angular 9 was made public. All programs now use the Ivy compiler and runtime by default, thanks to version 9. TypeScript 3.6 and 3.7 compatibility has been added to Angular. The Ivy compiler is where Angular first gained popularity.

Angular 10 

Version 9 of Angular was followed shortly by version 10. A new date range selector (Material UI library) and warnings about CommonJS import were among the new features it introduced.

Angular 11

On November 11, 2020, Angular 11, which includes improvements to Operation Byelog, better reporting and logging, quicker build, automatic font inlining, etc., was published.

Angular 12

The update was made available on May 12, 2021. The View Engine, scheduled to be eliminated from the following major release, is being phased out in Angular 12 in favor of Ivy. Certain aesthetic upgrades and document updates have also been implemented to make learning Angular easier.

Applications of  AngularJS

Menu

A menu is a navigation tool that responds to user input, which can be delivered via touch or mouse. The application's user-friendliness can be enhanced with Angular JS. The user experience can be improved by adding CSS elements to the previously existing HTML to enhance the page's overall appearance. 

Single-page application

A single-page website would mean less overload on the memory and a better user experience instead of having to load and fetch distinct pages from the memory as and when the user requests them each time they visit the site. This has more of a desktop application's behavior. 

Interactive user interface

Because HTML is a declarative language, easy to use and understand, Angular JS leverages it to describe the mobile application's user interface, making the whole thing simple. JavaScript is more difficult to use when defining the interface's elements than HTML.  
In contrast to knowing that JavaScript was used to construct the interface, HTML is immediately recognizable due to its format, tags, and other features. HTML can also comprehend the application's control flow (HTML is compatible with controllers in the MVC framework). 

Helpful in Unit Testing

The testing needs were taken into consideration when developing Angular JS. This is because testing is crucial and might prove essential in locating flaws and problems. It also aids in gaining a new perspective on the entire application. End-to-end testing is done on the Angular JS application for this shift in viewpoint. Unit testing in Angular JS is possible both with and without the Karma framework. Typically, unit testing for Angular JS controllers and directives is done separately. 
Additionally, the Angular JS application may be tested by creating individual test pages that would help make a particular application component, adding interactivity, and then determining whether it functions well.  

Useful in filtering data

It makes it easier to apply filters, such as adding formatting to decimal places, filtering an array depending on a particular parameter, reversing the order of ranges, or adding the pagination idea for web pages.  

Filters can be made to ensure that the functions are reliable and distinct from the application. Additionally, it provides that the parts only relate to data transformations concerning the data and not the entire application's code.    

Features of AngularJS

Some of the features of Angular JS are the following:

• Two-way data binding: Changes made to the view are instantly mirrored in the model, and the opposite is true. 
   
• Model View and Controller, or MVC, is the architecture used to create an angular application. According to the elements of MVC architecture, it divides the application into three parts: a model portion, a view part, and a controller part.
   
• Directives: AngularJS view combines model data with templates in HTML. The same functionality is achieved with Angular JS directives. How to merge data into an HTML template is explained. 
   
• Not Browser Specific: The fact that Angular applications are not browser specific means that any separate browser does not limit them.
   
• Routing: As a single-page application, Angular's ngRoute directive makes it easier for users to move between views.
   
• Dependency Injection: This integrated injection makes developing and comprehending applications simple.
   
• Speed and Performance: Angular has a faster speed and performance.
   
• Deep linking: This feature enables bookmarking of the website. The page's URL is preserved without causing its status to change.

MVC Architecture in AngularJS

MVC is an architectural pattern that holds the entire application design. It is an architecture that separates your software's more effective components into smaller ones. Both online and mobile app developers use it. The three components are Model, View, and Controller. 

The model manages the data logically. The view presents to the user the data from the model. Every time data changes, the controller revives the view. It contains the data flow into a model object. Ruby on Rails, Laravel, Zend Framework, CherryPy, Symphony, and more web frameworks use the MVC principle. 

A very smart way to manage an application is possible through the MVC architecture, which separates the architecture's display, logic, and data pieces. With Angular and MVC, we can focus on developing applications in a more declarative manner by simply selecting an HTML template.

Data Binding in AngularJS

Data binding is the procedure that synchronizes and connects two data sources. 
In AngularJS, data binding is used to synchronize the model and the view. When data in the model is updated, the idea is updated to reflect the change, and vice versa when data in the view is modified.

TWO-WAY Binding

Data sharing between a component class and its template is called two-way data binding. If you change data in one area, it will automatically reflect in the other.
When information needs to be revised, two-way data binding is used since it allows data to flow in both paths. 

Routing in AngularJS

A technique in AngularJS called routing allows the creation of Single Page Applications. You can use it to set unique URLs for the many types of content in your web apps. 
Use the ngRoute module if you want to move between different pages inside your application but also want it to be a SPA with no page reloading.
Without reloading the entire application, the ngRoute module routes your application to other pages.

Advantages of AngularJS

Some advantages of AngularJS are the following:

• Without the involvement of a developer, bi-directional data binding in AngularJS development allows quicker and simpler data binding.
   
• Change detection and unit testing are always possible with backward compatibility.
   
• The AngularJS MVC and MVVM paradigms separate design data from design, simplifying the structure and care of challenging AngularJS websites.
   
• Thanks to the open-source framework, the lack of other platforms or plugins makes the front-end development process more clear.
   
• When AngularJS code is neat and well-structured, it is more reusable.
   
• The performance and speed of AngularJS are better.
   
• JavaScript is a dynamically typed language, and Angular is a JavaScript framework. Due to this, angular has a powerful expressive capacity. However, angular lacks compiler assistance. Robust test code must be written for it as a result. It is simpler to test individual code components because dependency injection is built into the system. Also, Angular supports both unit testing and integration testing.
   
• Angular JS is simple to extend because of some built-in features. With the use of these built-in features, HTML's functionality can be increased by coupling a particular behavior to it. It is customized since one can add their own commands to it. Here, customized refers to modifying existing features or capabilities in order to meet unique requirements. Additionally, as customized software is created solely for each client, it includes user-friendly features rather than extraneous components.

Disadvantages of AngularJS

Some disadvantages of Angular JS are the following:

• Knowing the MVC architecture is required for using Angular JS.
   
• The AngularJS application is complex because it has multiple ways of taking out the same process.
   
• Its poor performance of scalability and improper one-way binding for mobile browsers are two of AngularJS's notable flaws.
   
• Users can access a simple page when third-party javascript tools are removed in an AngularJS app.
   
• If JavaScript is disabled on the computer where the AngularJS application is to run, it will not work.
   
• When using the Angular JS framework for the first time, debugging the scope can be challenging. Developers must therefore train themselves before taking on a project.
   
•  Every framework has some differences that one must learn to use.

Limitations of AngularJS

Some limitations of Angular JS are the following:

• When the javascript tools are removed from the Angular JS application, you cannot create a dynamic application.
   
• Because AngularJS is a JavaScript-only framework, it is not safe. To keep an application safe, server-side authentication and permission are essential.
   
• Memory leaks are a problem in JavaScript. Memory leaks are instances where an application no longer needs memory and, for a variety of reasons, the memory does not return to the pool of available memory. Memory leaks also cause other problems like slowdowns, crashes, and high latency.
   
• Angular JS is not supported everywhere. For example, Angular Js is incompatible with Internet Explorer 8.0.
   
• The rendering of websites and applications will take a long time if you use outdated equipment like computers or laptops. That occurs as a result of the browser's inability to handle overload and its inability to complete tasks like DOM manipulation. Also, if you are unfamiliar with the framework, there may be some aspects that you misuse and end up spending hours on.

Frequently Asked Questions

What is AngularJS?

AngularJS is a well-known JavaScript-based application framework that is open-source and cost-free that is used for building dynamic internet apps. Google still keeps an active society for Angular. It transforms static HTML into dynamic HTML by using HTML as a template language.

What is AngularJs used for?

AngularJs is a Javascript framework used to build applications and let us extend HTML’s syntax to express our application’s components clearly. It provides us with the tools for building a responsive website.

Is AngularJS a framework?

Yes, AngularJs is a framework for building responsive web applications. Its robust features like data binding and dependency injection eliminates much of the code we have to write.

Is AngularJS used for front end?

Angular is a free and open-source front-end framework that is mostly used to create Single Page Applications. If you want a new yet simpler approach to design online applications, Angular is the way to go.

Conclusion

The angular programming platform may be used to construct a single-page application for both desktop and mobile platforms. It creates apps with Typescript and HTML. In this Angular JS tutorial, we discussed what Angular JS is, its history, why you should learn it, different versions, apps, features, MVC design, data binding, routing, and the benefits, drawbacks, and limits of Angular JS.