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)

Registering providers

To do that you need to register a provider, and there are two places where you can do it. One is in the component decorator.

selector: 'talks-cmp',
template: `
<talk *ngFor="let t of talks" [talk]="t"></talk>
providers: [TalksAppBackend]
class TalksCmp {
constructor(backend:TalksAppBackend) {
this.talks = backend.fetchTalks();

And the other one is in the module decorator.

declarations: [FormattedRatingPipe, WatchButtonCmp, \
RateButtonCmp, TalkCmp, TalksCmp],
exports: [TalksCmp],
providers: [TalksAppBackend]
class TalksModule {}

What is the difference and which one should you prefer?

Generally, I recommend to register providers at the module level when they do not depend on the DOM, components, or directives. And only UI-related providers that have to be scoped to a...