Pro JavaScript for Web Apps pdf - EBook Free Download

CHAPTER 2 GETTING STARTED...This combination of elements redirects the user to a page called noscript.html, which is an HTMLdocument that tells the user that I require JavaScript (and, obviously, doesn’t rely on JavaScript itself).You can find this page in the source code download that accompanies this book and see the result inFigure 2-5.Figure 2-5. Enforcing a JavaScript-only policy in a web appIt is tempting to require JavaScript, but I recommend caution; you might be surprised by how manyusers don’t enable JavaScript or simply can’t. This is especially true for users in large corporations,where computers are usually locked down and where features that are common in the generalpopulation are disabled in the name of security, including, sadly, JavaScript in browsers. Some web appsjust don’t make sense without JavaScript, but give careful thought to the potential users/customers youwill be excluding before deciding that you are building one of them.• Note This is a book about building web apps with JavaScript, so I am not going to maintain progressiveenhancement in the chapters that follow. Don’t take that as an endorsement of a JavaScript-only policy. In my ownprojects, I try to support non-JavaScript users whenever possible, even when it requires a lot of additional effort.41www.it-ebooks.info