Introduction
Among the most powerful and bewitched frameworks for web applications is Angular. If you’re an experienced developer, you’ve likely used Angular at some point. But, still, Angular has a mature ecosystem that contains many of the advanced concepts that could help you to be more effective at building scalable, maintainable, and high-performance apps. In this article, we will explore the Top 10 Angular Concepts For Experienced developers should know.
Dependency Injection (DI)
Dependency Injection is one of the most powerful features of Angular. It lets you inject services or other dependencies into components and classes. It helps to manage dependencies, improve testability, and maintain a clean codebase. DI facilitates Angular in managing the instantiation and dependency injection of services as opposed to manually creating them for every component that requires it. So, you could be able to write clean and maintainable code on familiar technology if you understand how DI works behind the scenes.
RxJS and Observables
RxJS (Reactive Extensions for JavaScript) is an essential part of Angular. You can make the most out of asynchronous operations with Observables. RxJS is a very strong and powerful library for dumping not only HTTP requests but also user input events on your application and also managing the state changes.
Observables are streams of data that can be observed — and are well-suited for use cases in which you want to subscribe to the data you want. They offer ways to manage async events, map their data, and chain operations.
Understanding operators such as map, switchMap, and mergeMap is crucial to stream programming. These operators can help you make your applications better so the better you use these operators, the better responses you will get as seen now you are an experienced developer, and you should know when and how to utilize these operators to have a more efficient application.
The subject is another key concept in rxjs. It lets you broadcast data to several observers, and it’s used for use cases such as event handling and shared state management.
Angular Change Detection
This example also demonstrates the all-important change detection mechanism provided by Angular to keep the UI in sync with the component state. It has a change detection strategy to decide on updating the view depending on updates to data.
You have default Change Detection running automatically for every component in the component tree.
By using OnPush Change Detection, you can enhance performance by reducing the number of checks that Angular performs. OnPush mode tells Angular to only check a component when one of its input properties changes, or when an event (like a click) causes an update.
Angular change detection is an important topic to understand when writing high-performance Angular applications, specifically how it works, when, and where it triggers. This helps prevent bloated re-renders and makes sure the UI receives updates when it should.
NgModules and Lazy Loading
NgModules is a core functionality unit of Angular. They help you to organize your application by grouping together related components, services, and pipes in cohesive blocks of functionality. A good experienced developer should understand the proper way of designing and structuring modules to keep applications maintainable.
Core Module Core Module A module that contains services or components that are used throughout the application.
Feature modules: You can load the different modules lazily or eagerly as per the requirements. On the other hand, breaking the app into feature modules is a common practice.
Lazy Loading: Lazy loading means loading feature modules when the need arises. This means you no longer load code you don’t need right at the start, which improves your app’s performance. As an Angular developer, properly configuring your lazy-loaded modules can have a significant impact on your application startup time.
Custom Directives and Pipes
Directives and pipes are two of the strongest tools Angular provides for extending HTML and working with data. Although Angular provides many built-in directives and pipes, seasoned developers frequently develop custom ones tailored to their applications’ specific requirements.
Directives tell the DOM to do something. They can be used to write reusable components or do complex DOM manipulations.
The templates can transform data using pipes. Custom pipes let you format, filter, or sort data prior to its display in the view.
This is where creating your custom directives and pipes comes in, which will help you in the reusability and maintenance of code by removing the redundancy in the code.
Routing and Navigation in Angular
Routing is a core feature for single-page applications (SPAs). Angular comes with an excellent routing library to manage navigation between your different views as well as deep linking, lazy loading, and other things.
Route Guards: They enable access control to particular routes You might use them to protect routes from being accessed, validate conditions before navigating — like requiring the user to be authenticated to view a route, or restrict the route to only authenticated users of a certain role.
Child Routes: These help control nested components nested in a component. Being an Angular Developer, you should know the importance of having child routes and how to implement them properly to keep the navigation structure clean and in line.
Route Parameters and Query Parameters: An essential part of routing is handling dynamic URL parameters and query strings. Angular’s router, imports an entire module for URL-drivenData.
Expertise in routing and navigation helps you in building smooth and effective user flows in your application.
State Management
Over time as Angular applications grow, it becomes increasingly complicated to manage the application state. Angular itself does not have a built-in solution for state management, but different patterns and libraries can be used to keep the state of your application manageable.
Localised Routing by using Nested Routing in Angular: Angular has a built-in routing system which is very useful when the application has nested views. Dependency injection allows state management to be more centralized and provides a way for components to share simple data.
NgRx: NgRx is a comprehensive library for handling global state in Angular applications. It adopts the Redux pattern with Actions, Reducers, and Store to keep the application state predictable and to manage the flow of the modifiable state in a maintainable manner.
Akita for Angular: Akita is yet another state management library for Angular with a more flexible approach than NgRx. It helps you minimize the boilerplate code needed to manage state and handle async operations.
Knowing about state management solutions keeps your Angular-based application scalable, maintainable, and responsive.
Testing Angular Applications
Building robust applications involves testing, without a doubt. Angular offers a robust unit and end-to-end testing framework.
Jasmine and Karma: Jasmine is basically the testing framework for Angular unit tests. Karma is the test runner used to run tests in real browsers. With a little bit of background, you probably already know how to write test cases, mock dependencies and manage async operations on tests.
Tools for Angular Testing: One of the Angular test utilities that you get from Angular itself is TestBed.
Protractor (End-to-End Testing): Protractor is Angular’s end-to-end testing tool that lets you simulate a real user experience and test your application’s functionality from the user’s standpoint.
The holy grail of reliability, maintainability, and regression-free API and UI —> testing your Angular applications rigorously.
Angular Forms
Translation: Forms are a very important aspect of web applications and Angular has great tools to manage template-driven or reactive forms. We can see that the skills learned from styling the two elements will go a long way.
Template-Driven Forms: These are simpler-to-use forms that use Angular’s two-way data binding to connect the form inputs and the component properties. They are simpler to implement but may become unwieldy for larger forms and more complicated validations.
Reactive Forms: Reactive forms are more robust and flexible. They enable you to specify form controls and validations in the component class and link them to the template. They are best for complex forms and give better control of the form status.
Custom validators: Angular also allows developers to create their own custom validators which can be used for several complex conditions that need to be checked on form fields. This technique helps you to validate if your forms satisfy the required business rules.
Learning Angular forms is a convenient way to deal with data provided by users and makes sure that the data in forms is processed and validated properly.
Performance Optimization
Web application’ success rely vastly on its performance. Luckily, Angular does offer many tools and approaches to help you speed up your application.
Change detection strategy: As already discussed, Angular uses a change detection mechanism to update the view in case of data changes. Will change detection strategy OnPush improve performance in this case?
AOT Compilation: With AOT compilation, Angular can compile your templates and components at build time, rather than runtime, which minimizes the work the browser must do at runtime. This increases the first-time load speed of your application.
Tree Shaking: Tree shaking is a term that refers to the elimination of parts of the code that are never used in the final build. If you notice that only the necessary code is included in the final bundle, your angular build system is using the tree shaking technique, which helps reduce the size of the application.
Lazy Loading: As mentioned above, lazy loading also reduces the initial load time as only feature modules that are currently needed are loaded.
Now, while Angular is an amazing front-end framework, for a large-scale web application, performance optimization is very critical to make sure that your application is giving a decent runtime experience for its users.
Conclusion
With this list of 10 advanced concepts to master you will be on your way to creating more efficient, maintainable, and scalable applications as an experienced Angular developer. Dependency Injection, RxJS, Angular change detection, state management, and performance optimization can result in better-performing and scalable applications. Continue to explore, and learn about the features and what they can do to aid you in the quest for angular applications of high quality.
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