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)


And this is how the dependency resolution algorithm works:

// this is pseudocode.
let inj = this;
while (inj) {
if (inj.has(requestedDependency)) {
return inj.get(requestedDependency);
} else {
inj = inj.parent;
throw new NoProviderError(requestedDependency);

When resolving the backend dependency of TalksCmp, Angular will start with the injector of the talks component itself. Then, if it is unsuccessful, it will climb up to the injector of the app component, and, finally, will move up to the injector created from AppModule. That is why, for TalksAppBackend to be resolved, you need to register it at TalkCmp, AppCmp, or AppModule.