Introduction

Introducing Aurelia

Aurelia is a relatively new, open-source JavaScript library/framework that simplifies the creation of web-based applications. Building applications for the web is constantly changing, and new specifications are being introduced at an ever-increasing cadence. This calls for a framework that is forward-facing and embraces the new and upcoming technology landscape. Aurelia does this, and it does it very well. As we take a look at what it means to build an Aurelia application, you will be pleasantly surprised at how simple and easy it is to do things. This simplicity is hard to achieve, but architect Rob Eisenberg and his team have done exactly that. If you have been wanting to find a front-end framework that allows you to develop using ECMA-Script 2015 and ECMA-Script 2016, your wait is over. We will take a look at all the features of Aurelia and what makes it a serious contender for the front-end space when evaluating your next toolset.

History

Let’s start with a little history. Rob Eisenberg has been famous for creating open-source frameworks for developers for a very long time. He started out by creating Caliburn, a framework for WPF and Silverlight developers. He then gave a talk on building your MVVM (model-view-viewmodel) framework that kick-started Caliburn.Micro, the second iteration of Caliburn. Next, he created Durandal, a front-end framework for JavaScript. It worked with Knockout and was very similar to Caliburn.Micro, but still very much an ES5 solution. Fast-forward to the beginning of 2015, and Rob announced Aurelia. This time, he decided to use features for the JavaScript language that were being introduced in ES6 and ES7, but were not yet ready. He was able to do this by transpiling the JavaScript code to an ES5-compliant version that current browsers could understand. Transpilation is the means of writing code in ES6 and ES7, and converting it to ES5 code. Transpilation does not compile your code, but simply changes it from one version of JavaScript to another. Microsoft’s TypeScript is a good example of a superset of JavaScript that is transpiled to ES5 JavaScript. This is truly exciting, as it brings many new features to JavaScript that move the language closer to parity with mature languages such as Java and C#, but without the wait. You can code Aurelia applications using a lot of the same semantics and separation of concerns that you enjoy when developing in Java or C#.

Web components

One thing you will hear a lot is talk about web components. Most of the mature frameworks on the market today support this concept of allowing the developer to create components that encapsulate business logic and behavior for reuse in applications. Aurelia is no different, and it tries to adhere as closely as possible to the specification for web components. In Aurelia, they are called custom elements, so that any elements you create will work and play nicely with other frameworks, as well. Aurelia plays nicely with other frameworks and integrates easily with Polymer, for example.

Contents

Throughout the rest of the book, we will take a look at the core pieces that make up Aurelia. Aurelia was designed from the ground up to be modular. If there is a module that you don’t want to use, or if you want to use another implementation, this is feasible, and the framework makes it very easy to do so. The first few chapters will be focused on getting your machine set up and going over the semantics of ES6 and ES7 features used throughout Aurelia. If you are not familiar with the syntax, don’t worry—you will quickly become a fan.