John Paxton

The Document Object Model

Working with the Document Object Model (the DOM) is a critical component of the professional JavaScript programmers toolkit. A comprehensive understanding of DOM scripting yields benefits not only in the range of applications we can build, but also in the quality of those applications. Like most features of JavaScript, the DOM has a somewhat checkered history. But with modern browsers, it is easier than ever to manipulate and interact with the DOM unobtrusively. Understanding how to use this technology and how best to wield it can give you a head start toward developing your next web application.

Professional JavaScript Techniques

Welcome to Pro JavaScript Techniques. This book provides an overview of the current state of JavaScript, particularly as it applies to the professional programmer. Who is the professional programmer? Someone who has a firm grasp of the basics of JavaScript (and probably several other languages). You are interested in the breadth and depth of JavaScript. You want to look at the typical features like the Document Object Model (DOM), but also learn about whats going on with all this talk of Model-View-Controller (MVC) on the client side. Updated APIs, new features and functionality, and creative applications of code are what you are looking for here.

The Future of JavaScript

We have taken quite the tour of JavaScript in this book. It is clear that JavaScript is a language in transition. From its humble beginnings as something of a toy language, JavaScript has ascended to the level of an enterprise-critical language. In the process, the seams have begun to show and, frankly, come somewhat loose. When developers from more mature languages come to JavaScript, they often marvel at what we have accomplished, given JavaScripts limitations. They are given to wonder at how the language got so far, and whether it will improve in the future.

Web Production Tools

The tools for developing websites have matured over the years. We went from using simple editors like Notepad to full-scale development environments like WebStorm. We also have libraries like JQuery. We can use Handlebars as a templating engine and AngularJS as a full MVC framework. There are also unit testing frameworks and version control systems to help us do our jobs better and faster. So now that we have all of these things available, how do we keep them all organized?

Debugging JavaScript Code

Sometimes its not the writing of code, but the management of it that gets to us, that drives us up a wall and back to our favorite video game. Why does it work on this machine, not that one? What do you mean, double-equals (==) is bad and triple-equals (===) is good? Why is running tests such a hassle? How should I package this code for distribution? We are plagued by questions, distracted by questions that do not directly bear on the code we are writing.

Features, Functions, and Objects

Objects are the fundamental units of JavaScript. Virtually everything in JavaScript is an object and interacts on an object-oriented level. To build up this solid object-oriented language, JavaScript includes an arsenal of features that make it unique in both its foundation and its capabilities.

JavaScript and Form Validation

It is inevitable that, when encountering a form, one considers the fate of the data for that form. One of the first practical applications of JavaScript was providing a way to validate data on the client side, instead of having to endure a round trip to the server. Form validation was a bit ad hoc at the time, with no practical API and no real integration with the browser. Instead, programmers bound together events and basic text manipulation to provide a handy user interface enhancement.

AngularJS and Testing

In the previous chapter, you learned how to use the current set of tools to quickly put a site together and use version control to keep track of all the files you work with and the difference between them. In this chapter, we’ll dig in and understand how frameworks like Angular work.

Creating Reusable Code

In the introduction to the last chapter, we discussed objects as the fundamental unit of JavaScript. Having addressed JavaScript object literals, we will use a large portion of this chapter to examine how those objects interact with object-oriented programming. Here, JavaScript exists in a state of tension between classical programming and JavaScripts own, nearly unique capabilities.

Introduction to Ajax

Ajax is a term coined by Jesse James Garrett of Adaptive Path to describe the asynchronous client-to-server communication that is made possible using the XMLHttpRequest object, which is provided by all modern browsers. An acronym for A synchronous JavaScript and XML, Ajax has evolved into a term used to encapsulate the techniques necessary to create a dynamic web application. Additionally, the individual components of the Ajax technique are completely interchangeable—using JSON instead of XML (for example) is perfectly valid.