This is a rather advanced book which delves into inner workings of AngularJS framework. The most needed feature of a modern web-based application is custom widgets, since HTML5 only includes very basic UI components. The book explains how such customized elements can be built by introducing the concept of directives. Directives are turned into DOM elements through a process of compilation and linking, which is the foundation of AngularJS’s machinery.
Being the most important extensibility mechanism, directives need to interact with other elements through a controller, as well as with current application state called scope. There are multiple kinds of interactions, each one tailored to specific use case. The book provides numerous examples which greatly facilitate understanding of rather complicated AngularJS concepts.