preface

A major framework for many years, Angular has influenced a generation of web technologies. Even developers who haven’t used it have benefitted from its existence, as it helped popularize a number of important concepts and technologies.

Early in its AngularJS days (version 1.x is known as AngularJS), it became perhaps the most popular web application framework of its time. But the 1.x version had limitations, and a number of optimizations were built into the framework. The concept of two-way databinding (being able to sync data between the controller and the view automatically), which was touted early on as its best feature, became a performance bottleneck in large applications that abused its utility. To help mitigate this problem, one-way and one-time binding options were introduced to improve performance, but they required developers to opt in. Also, components were introduced as a better way to organize and structure applications, but taking advantage of them required refactoring of existing applications.

You could build an amazing and performant application with AngularJS 1.x, but it wasn’t always the default mode and required unlearning concepts that were believed to be best practices from earlier releases. Simply put, writing well-designed applications was possible because of workarounds from the original concepts that AngularJS embraced.