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)


Declarations, imports, and exports

NgModules are the unit of compilation and distribution of Angular components and pipes. In many ways, they are similar to ES6 modules, in that they have declarations, imports, and exports.

Let's look at this example:

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

declarations: [AppCmp],
imports: [BrowserModule, TalksModule],
bootstrap: [AppCmp]
class AppModule {}

Here we define two modules: TalksModule and AppModule. TalksModule has all the components and pipes that do actual work in the application, whereas AppModule has only AppCmp, which is a thin application shell.

TalksModule declares four components and one pipe. The four components can use each other in their templates, similar to how classes defined in an ES module can refer to each other...