Knockout is built around a pattern that started in Microsoft. This model is Model-View-ViewModel (MVVM), and I think introducing this pattern to newcomers is one of the biggest obstacles to wider adoption. Nearly every other JavaScript library or framework, along with most server-side frameworks, has been built around the Model-View-Controller (MVC) pattern, and the differences between the two are sometimes confusing, even for experienced developers. This problem is compounded by the fact that some larger frameworks, such as AngularJS, end up with a pattern that is nearly identical to MVVM.
Knockout's documentation is excellent, and its live examples and interactive tutorials are some of the best. When it comes to organizing full applications, though, more explanation is required. When I started writing this book, there was only one book on Knockout on Amazon, and it didn't have very favorable reviews. It seemed like a complete guide to using Knockout as the central piece of a frontend stack was missing.
I have been using Knockout for 3 years now, and I've been an active member of the community on StackOverflow and GitHub for 2 years. I've used Knockout in several professional applications as well as a dozen or so personal projects. It is, by far, my favorite JavaScript library, and I strongly prefer MVVM over MVC for developing client applications. Hopefully, you feel that this book gives you everything you need in order to be successful with Knockout.
Knockout 3.2 was released while this book was being written. Chapter 4, Application Development with Components and Modules, was rewritten to include the components feature, and some minor changes were made to other chapters in order to make them accurate. However, most of the code samples were written against Knockout 3.1, and so they do not take advantage of pure computed observables or other features that were released in Knockout 3.2.
Chapter 1, Knockout Essentials, covers the environment setup and basic use of the Knockout library. It also covers data binding, observables, binding handlers, and extenders, and demonstrates a simple Knockout Contacts List application.
Chapter 2, Extending Knockout with Custom Binding Handlers, gives you in-depth knowledge of how to create and use custom binding handlers. It includes simple single-property binding handlers as well as complex multiproperty binding handlers with templates.
Chapter 3, Extending Knockout with Preprocessors and Providers, teaches you how to use node and binding preprocessors and binding providers to customize Knockout's syntax. It also explores the Knockout Punches library.
Chapter 4, Application Development with Components and Modules, explains how to use RequireJS Asynchronous Module Definitions (AMDs) with Knockout to create organized, modular viewmodels. It also teaches you how to use the new Knockout components feature and how to continue working with the Contacts List demo application.
Chapter 5, Durandal – the Knockout Framework, explores the basics of the Knockout-based Durandal framework. This chapter covers composition, routing, modal dialogs, and custom widgets.
Chapter 6, Advanced Durandal, continues looking at the use of the Durandal framework. This chapter covers events, advanced composition, nested routers, custom dialogs, and the observable plugin.
Chapter 7, Best Practices, takes a deep dive into the inner workings of Knockout. It includes dependency detection and the publish/subscribe implementation, observable inheritance, the template engine, and a complete Knockout utility (ko.utils) reference.
Chapter 8, Plugins and Other Knockout Libraries, gives you an overview of the recommended patterns and practices for Knockout developers.
Chapter 9, Under the Hood, covers several popular Knockout plugins, including Knockout validation, Knockout mapping, and the new Knockout-ES5 plugin.
You need an ES5-compatible browser, Git, and Node.js. The code in this book will run on any operating system.
If you are an experienced JavaScript developer who is looking for new tools to build web applications and gain an understanding of core elements and applications, this is the book for you. It is assumed that you have basic knowledge of DOM, JavaScript, and KnockoutJS.
In this book, you will find a number of styles of text that distinguish between different kinds of information. Here are some examples of these styles, and an explanation of their meaning.
Code words in text, database table names, folder names, filenames, file extensions, pathnames, dummy URLs, user input, and Twitter handles are shown as follows: "All the code needed to start each chapter can be found in a branch named cp[chapter#]-[sample]."
A block of code is set as follows:
var subtotal = ko.observable(0);
var tax = ko.observable(0.05);
var total = ko.computed(function() {
var subtotal = parseFloat(self.subtotal()),
tax = parseFloat(self.tax());
return subtotal * (1 + tax);
});New terms and important words are shown in bold. Words that you see on the screen, in menus or dialog boxes for example, appear in the text like this: "You might have noticed in the previous section that when the Contacts page view model communicated with the data service, it wasn't dealing with JSON, but real JavaScript objects."
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Additionally, the code for this book is part of a Git repository, which is available on GitHub at https://github.com/tyrsius/MasteringKnockout. The code samples are organized as branches in the repository.
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