on August 1, 2007
Throughout the ten chapters and 499 pages of this book, there is very little that isn't covered on the topic. Let's take a look at the organization and flow of the book:
Lastly we are introduced to the eight example scripts that we will encounter: Textarea MaxLength, Usable Forms, Form Validation, Dropdown Menu, Edit Style Sheet, Sandwich Picker, XMLHTTP Speed Meter, and Site Survey.
This chapter provides a little more context and history into the different browser families. We look not only at browsers but other devices such as mobile phones and screen readers. We look at each of these and are then shown some of the incompatibilities that they suffer. We address the problems and look to build solutions to patch the holes. Next we look at solving problems by using two different techniques: object detection and browser detection. Object detection works by checking if the methods you are using are supported before you use them. Browser detection tries to detect the current User Agent and then build from there. Browser detection has many flaws associated with it. One specifically is browser spoofing where you can send a different User Agent string to the server, lying to the application about the available technology. There are correct uses, but this should mostly be avoided.
Planning is important for all projects. Here we are introduced to preparing our application for enhancements. This involves having the proper placements of hooks. Hooks are found by using an ID, class, custom attributes (not a widely accepted solution), and name/value pairs.
Once we have our hooks in place, we have to get access to them to make our modifications. Having access is only part of the process. We also have to learn how to generate content when necessary and understanding the relationships inside of the DOM. We get a brief primer on setting up our script tag and how we can utilize multiple scripts if necessary.
Our hooks are in place, and we know where we want to apply our effects. How and when should they fire? We stop to take a look at the initialization of scripts and the load event. This method has its pitfalls, which are discussed and alternate solutions are addressed. We take a look back to the example scripts for some more insight and real-world use cases.
This section looks at the Browser Object Model and the window object. We take a look at the global window object and its impact on creating new pages and cross communication between windows. We then look at navigation within the window and the location and history. We learn how to manipulate the geometry of the window, and how to retrieve information about the current window dimensions.
The chapter rounds off with discussion of some miscellaneous functions such as alert, confirm, prompt and timeouts and intervals. We take a closer look at some of the available methods for the document object. Finally, we take a look at working with cookies and utilizing/managing them within our application.
This is probably one of the most important sections of this book. This section gives a thorough look at all of the available events. The chapter first starts by looking at some compatibilities and how to resolve them case by case. We take an in-depth look at all of the available events at our disposal and how they work. We look at event registration and the best way to handle it. The rest of this chapter discusses event bubbling and capturing and the browser support related to each, the event object and its properties available to us, targeting your elements, and then implementing some of our new-found knowledge in the example scripts. Sometimes grasping events and event registration can be tough, but this chapter makes it easy through illustration and the example scripts.
However, it is never that easy. Traversing the DOM can sometimes be painful, especially when you see some of the differences between browsers. We take a look at how to find our nodes, how we can retrieve information about those nodes, and how we can change our document tree through appending, inserting, removing, and replacing. We are also introduced to creating elements and creating text nodes, and then how we can achieve some of the above tasks.
The last parts of this chapter look at some examples of keeping the clean separation, but applying some visual enhancements. We work through some examples of toggling display of elements, animating elements, and changing the dimensions and position of elements.
This chapter is all about AJAX. We look at the XMLHttpRequest object and how to make it work cross browser through some conditional checks. Once we have sent the request, we need to know how to handle the response. We look at the different statuses and response codes that we will be dealing with and how to set callback functions to handle the response. We look at the available return formats such as XML, HTML, JSON, and CSV. The final part to this chapter looks at the impact that AJAX has on accessibility.