Book Image

Essential Angular

By : Victor Savkin, Jeff Cross
Book Image

Essential Angular

By: Victor Savkin, Jeff Cross

Overview of this book

Essential Angular is a concise, complete overview of the key aspects of Angular, written by two Angular core contributors. The book covers the framework's mental model, its API, and the design principles behind it. This book is fully up to date with the latest release of Angular. Essential Angular gives you a strong foundation in the core Angular technology. It will help you put all the concepts into the right places so you will have a good understanding of why the framework is the way it is. Read this book after you have toyed around with the framework, but before you embark on writing your first serious Angular application. This book covers concepts such as the differences between Just-In-Time (JIT) and Ahead-Of-Time (AOT) compilation in Angular, alongside NgModules, components and directives. It also goes into detail on Dependency Injection and Change Detection: essential skills for Angular developers to master. The book finishes with a look at testing, and how to integrate different testing methodologies in your Angular code.
Table of Contents (11 chapters)

Input and output properties

A component has input and output properties, which can be defined in the component decorator or using property decorators.

class TalkCmp {
@Input() talk: Talk;
@Output() rate: EventEmitter;

Data flows into a component via input properties. Data flows out of a component via output properties, hence the names: input and output.

Input and output properties are the public API of a component. You use them when you instantiate a component in your application.

<talk-cmp [talk]="someExp" (rate)="onRate($event.rating)"></talk-cmp>;

You can set input properties using property bindings, through square brackets. You can subscribe to output properties using event bindings, through parenthesis.