Book Image

Learning Angular - Fourth Edition

By : Aristeidis Bampakos, Pablo Deeleman
5 (1)
Book Image

Learning Angular - Fourth Edition

5 (1)
By: Aristeidis Bampakos, Pablo Deeleman

Overview of this book

As Angular continues to reign as one of the top JavaScript frameworks, more developers are seeking out the best way to get started with this extraordinarily flexible and secure framework. Learning Angular, now in its fourth edition, will show you how you can use it to achieve cross-platform high performance with the latest web techniques, extensive integration with modern web standards, and integrated development environments (IDEs). The book is especially useful for those new to Angular and will help you to get to grips with the bare bones of the framework to start developing Angular apps. You'll learn how to develop apps by harnessing the power of the Angular command-line interface (CLI), write unit tests, style your apps by following the Material Design guidelines, and finally, deploy them to a hosting provider. Updated for Angular 15, this new edition covers lots of new features and tutorials that address the current frontend web development challenges. You’ll find a new dedicated chapter on observables and RxJS, more on error handling and debugging in Angular, and new real-life examples. By the end of this book, you’ll not only be able to create Angular applications with TypeScript from scratch, but also enhance your coding skills with best practices.
Table of Contents (17 chapters)
15
Other Books You May Enjoy
16
Index

Manipulating form data

The FormGroup class contains two methods that we can use to change the values of a form programmatically:

  • setValue: Replaces values in all the controls of the form
  • patchValue: Updates values in specific controls of the form

The setValue method accepts an object as a parameter that contains key-value pairs for all form controls. If we want to fill in the details of a product in the create product component programmatically, we should use the following snippet:

this.productForm.setValue({
  name: 'New product',
  price: 150
});

In the preceding snippet, each key of the object passed in the setValue method must match the name of each control in the form. If we omit one, Angular will throw an error.

If, on the contrary, we want to fill in some of the details of a product, we can use the patchValue method:

this.productForm.patchValue({
  price: 150
});

The ...