Yakov Fain and Anton Moiseev - Angular Development with Typescript

Our quest for a good JavaScript framework started about five years ago. One of our largest projects was written using the Apache Flex framework (formerly Adobe Flex). Flex is an excellent framework for developing web UIs, but it requires Flash Player, which isnt in favor anymore.

After trying several pilot JavaScript projects, we noticed a substantial drop in our developers productivity. A task that required one day in Flex and ActionScript would need three days in other JavaScript frameworks, including AngularJS. The main reasons were the lack of types in JavaScript, poor IDE support, and the absence of compiler support.

After switching to Angular and TypeScript, we can confirm that its the most productive way of developing mid- to large-size web applications that can run in any modern browser, as well as on mobile platforms.

These are the main reasons we believe that Angular and TypeScript are the right tools for developing web applications:

• Clean separation of UI and app logic. Theres a clean separation between the code that renders the UI and the code that implements application logic. The UI doesnt have to be rendered in HTML, and there are already products that support native UI rendering for iOS and Android.
• Modularization. Theres a simple mechanism for modularizing applications with support for the lazy loading of modules.
• Navigation. The router supports complex navigation scenarios in single-page applications.
• Loose coupling. Dependency injection gives you a clean way to implement loose coupling between components and services. Binding and events allow you to create reusable and loosely coupled components.
• Component lifecycle. Each component goes through a well-defined lifecycle, and hooks for intercepting important component events are available for application developers.
• Change detection. An automatic (and fast) change-detection mechanism spares you from the need to manually force UI updates while providing you a way to fine-tune this process.
• No callback hell. Angular comes with the RxJS library, which allows you to arrange subscription-based processing of asynchronous data, eliminating callback hell.
• Forms and validation. Support for forms and custom validation is well designed. You can create forms either by adding directives to form elements in the template or programmatically.
• Testing. Unit and end-to-end testing are well supported, and you can integrate tests into your automated build process.
• Tooling. Angular is well supported by IDEs. The TypeScript code analyzer warns you about errors as you type. Angular CLI quickly generates a new project and various artifacts (such as components and services), comes with a web server, and performs dev and prod builds, sparing developers from dealing with configuration scripts.
• Concise code. Using TypeScript classes and interfaces makes your code concise and easy to read and write.
• Compilers. The TypeScript code can be compiled into ES3, ES5, or the latest versions of JavaScript. Ahead-of-time compilation of app templates makes the initial app rendering faster and eliminates the need to package the Angular compiler with your app.
• Server-side rendering. Angular Universal turns your app into HTML in an offline build step that can be used for server-side rendering, which in turn greatly improves indexing by search engines and SEO.
• Modern-looking UI components. Angular Material offers more than 35 well-designed UI components.

As you can see from this list, Angular comes with the batteries included.

From a project-management perspective, Angular is appealing, because there are already more than a million AngularJS developers, and most of them will switch to Angular. Having a large pool of workers with specific skills is an important consideration for selecting a technology for new projects. Besides, there are more than 15 million Java and .NET developers, combined, and many of them will find the syntax of TypeScript a lot more appealing than JavaScript because of its support for classes, interfaces, generics, annotations, class member variables, and private and public variables, not to mention its helpful compiler and solid support from familiar IDEs. New major releases of Angular are published semiannually, and the upgrades from one release to another go smoothly.

Writing the first edition of this book was difficult, because we started with early alpha versions of the framework, which were changing quite frequently. Now, the framework is stable, and after three years of real-world development and running countless workshops, we understand and can explain the Angular framework a lot better. We do encourage you to buy this second edition of the book even if you already own the first one.