Angular is a component-based application design framework for building scalable, reactive, and efficient single-page apps. It provides a wide range of tools and well-integrated libraries to build, develop and test your applications. The angular applications are written by composing HTML templates and components are created to manage these HTML templates. The logic of the applications is given in the services, these services and components are wrapped into the modules.
Angular Evolution
Angular framework was first introduced a decade ago in 2010 under the name Angular JS. Through the course of years, the framework has developed with various updates. AngularJS 1.x is seen as a JavaScript-based framework that creates rich web and mobile applications. The Model-View-Controller (MVC) and its variations Model-View-Presenter (MVP) and Model-View-View-Model (MVVM) have been considered as an Angular JS architecture. Even though Angular JS is a proven architectural pattern and is the standard solution for an application with a view, there are certain disadvantages.
- Memory leakage.
- Internet Explorer 8.0 doesn’t support Angular JS.
- AngularJS totally depends on JavaScript.
Angular 2+ was typescript-based free open-source technology used to develop web applications and mobile applications. It is a component-based framework and has a collection of well-integrated libraries. Angular 2+ is very simple and pretty straightforward to use. Angular 2+ is typescript, which allows you to validate the code with ease and show the error at the time of typing. Implementing forms and validation are much simpler and more effective with angular 2+. With recent advancements, Agular’s responsive design has shifted towards a mobile-first approach.
Angular 3 was skipped because the framework was developed in a MonoRepo, which is a single repo, and its router package was already in the third version. To avoid confusion in terms of dependency, Angular third version was skipped. Angular 4 was released in 2017 which was compatible with both typescript 2.1 and 2.2. This version improved the speed and performance by a good extent. Angular 5 was released around the end of 2017 and it was comprised of many new features and improvements. It provided an optimizer that removed unnecessary code from the applications. It also provided an improved compiler and improvements in angular universal for code allocation, and most important of all it supported typescript 2.4. Angular 6 was released in early 2018 which introduced Angular elements and Angular Rendering Engine. Angular 7 was released later that year with major performance improvements. It also provided a drag and drop module, angular material, and component Dev kit. Angular 8 was released in 2019 with its dependencies updated, improved web worker bundling, and provided a new lazy loading syntax and also includes angular firebase.
Angular 9 was introduced in 2020, it provided new features and updates such as more consistent ng, updated and improved API extractor, dependency injection update, better speed and performance, AOT build ensures a faster and better performing compiler, supports typescript 3.7. Angular 10 was released in June 2020 with new updates and features such as a new data range picker, an updated compiler, Optional stricter settings to catch bugs ahead, performance improvements, supports typescript 3.9.
Angular 11 was released in November 2020, major improvements are router performance, automatic inlining of fonts, updated Hot Module Replacement(HMR), provides faster builds and improved performance, supports Typescript 4 and Webpack 5, component test harness with parallel functions and improved performance. Angular 12 was released on May 2021, with major improvements in styling, supports Typescript 4.2 and Webpack 5.3.7, nullish coalescing for writing better and cleaner code in typescript classes, improved ng, includes protractor, new dev tools, Migrating from legacy i18n message IDs. Angular 13 is also available with impactful changes towards optimizations. Angular 13 no longer has the view engine, with reduced dependency on ngcc, we can hope for faster and improved compilation. Angular 13 supports typescript 4.4 and provides an improved and modernized Angular Package Format, improved Angular CLI and it no longer supports IE11.
Why Angular?
With the evolution of Angular over the years, it has become one of the most recommended for businesses and enterprises for various reasons. Angular is used to develop single-page client applications using HTML and TypeScript. Angular offers two-way data binding and it shares the data between Model as well as View. Hence, when data is modified or changed, components get updated automatically in real-time. Code reusability in an angular application is high.
Angular makes a great recommendation to businesses as it provides a framework that can work well with back-end languages and also very well combines the business logic and UI. Angular provides an effective cross-platform development framework that makes the development process easier with reduced cost. Though initially, it is a little complex to learn, it is worth it as it provides high-quality applications. Angular provides Typescript that facilitates the developers to write clean and neat code, which makes the fixing of the bugs that much easier. The framework is structured around component-based development, which aids in a steady development process with consistent and high reusability of components. This further facilitates in providing better maintainability and productivity.
The evolution of angular has provided various new features and improvements that have significantly increased the speed and optimized the performance. The older versions had larger bundles size which hindered the fast loading of the applications, but with recent improvements such as lazy load modules and Ivy Renderer, we can create lightweight web applications that are faster and better. To overcome productivity issues and to provide a faster development process, features such as dependency injection and angular services are also provided. Angular keeps ever-evolving based on requests from google and the angular community making it one of the ideal frameworks for businesses and enterprises.
Angular Architecture and it’s core components
The angular architecture contains the following core components
- Module
- Meta Data
- Directives
- Pipe
- Service
- Decorators
Module
Module in Angular refers to a place where you group the components, directives, pipes, and services, which are related to the application. Every Angular app has a root module that has the bootstrap mechanism to launch the app.
Meta Data
Metadata is used to decorate a class so that it can configure the expected behavior of the class. Metadata is attached to TypeScript using the decorator.
Directives
Directives are classes that are used to change the behavior or view of DOM elements in Angular applications.
Three types of Angular directives are as follows:
- Components – directives with a template.
- Attribute directives – directives that change the appearance or behaviour of an element, component, or another directive.
- Structural directives – directives that change the DOM layout by adding and removing DOM elements.
Pipe
The pipe is asimple way to transform values in an Angular template. Some of the built-in pipes in angular are CurrencyPipe, DatePipe, JsonPipe, LowerCasePipe, UpperCasePipe, PercentPipe, SlicePipe.
Service
Services are used to access and share the methods and properties with the other components in the entire project. It reduces the function and properties repetitions in the entire project. HTTP requests and responses will be handled in the services.
There are two types of services in angular.
- Built-in services – There are approximately 30 built-in services in angular.
- Custom services – In angular, if the user wants to create their own service, they can opt for custom services.
Decorators
Angular decorators are used to storing metadata. It is about a class, method, or property. There are four types of decorators in Angular:
- Class Decorators
- Property Decorators
- Method Decorators
- Parameter Decorators
1. Class Decorators
Class Decorators are top-level decorators. It defines the purpose of the class.
2. Property Decorators
Property decorators are used to specific properties within the class. @Input() is the example for the property decorator.
3. Method Decorators
A Method Decorator is used to specify the methods within your class with functionality. @HostListener() is an example of a method decorator.
4. Parameter Decorators
Parameter decorators are used to decorating parameters. It is used in the class constructors. @Inject() is the example for the parameter decorator
Testing
Angular uses the Jasmine testing framework. It provides multiple functionalities to test. Karma is the task-runner, uses a configuration file to set the start-up, reporters, and testing framework.
Limitations of Angular
Angular though it is one of the popular modern-day frameworks that is employed, it also has a few limitations:
- Steep learning curve
Though Angular is a great framework, it’s sometimes is quite difficult even for people with experience in HTML, JS, CSS, and for people who are not much used to n-tier architecture. They can find it hard to learn some of the concepts as it has its own set of rules, which might be difficult and uncomfortable for novice learners.
- Limited SEO options
Though Angular is a great and powerful platform to build single-page applications, limited SEO options and poor accessibility to search engine crawlers are some of the major drawbacks. This makes it difficult to place the website correctly in the list provided by the search engines.
- Complex and Verbose
Angular has such a complex framework of modules and complex capabilities for integration and customization. Though angular provides an array of online tutorials and documentation, it’s quite uncomfortable to learn in the beginning. A slow and steady pace is recommended to learn the platform and language.
- Complex directives
Angular has three directives -attribute directive, structural directive, and component directive. The three directives have their own limitations and it’s quite complex for beginners to understand when to use what.
Angular Prerequisites
Angular requires the following prerequisites – NodeJS, Angular CLI, and Text Editor
Supported by Google
Google is offering a Long-Term Support (LTS) for Angular to scale up to enterprise Angular applications development. Netflix, Gmail, YouTube TV, Upwork, and other organizations are also using the Angular framework for application development.
Open-Replay
Open Replay is an open-source tool, developers can integrate this with the angular applications. When the user uses the application, open-replay will track it. So the developers can easily come to know how much the application is user-friendly. It has the network tracker, redux, NgRx action tracker, and profile tracker plugins. It also captures the performance of the application.
With this article we wanted to give you an introduction to Angular, the evolution of angular over the decade, the need for angular in today’s business world, and its core architecture. We covered the core components of the architecture and also the limitations of the framework. Bottom line is that Angular has become one of the best frameworks for developing single page apps.
