And indeed, we have seen an explosion of Ajax applications in the last year or so. Startups established to create Ajax versions of existing applications already have been bought by companies such as Google. Existing Web sites are scrambling to include Ajax functionality. Book publishers are printing Ajax-related books like they're going out of style. I probably know of at least six toolkits for adding Ajax to applications, and new ones are being released all the time.
Much of the excitement behind Ajax is the freedom it gives designers and developers. Before Ajax, Web applications could be beautiful to look at, but their page-based interfaces were reminiscent of old mainframes, whose applications ran on a page model. What, you want to create an application that is updated incrementally? Sorry, the HTTP/HTML combo means that you either got a new page, and got to enjoy the functionality that it offered, or you stayed on the current one. Every page update had to be accompanied by an HTTP request, and vice versa.
There is no doubt that Ajax applications have a cleaner look and feel to them than old-style Web applications. They feel more natural and responsive, and it's easy to imagine all Web applications looking like this within a few years. This is probably a good thing overall, and I'm looking forward to what the future will bring. In fact, I would guess that within a few years, saying you're an “Ajax developer” will sound as funny as saying you're a “cookie developer”, or a “DOM developer” or even a “database developer”. Just as understanding each of these technologies is now an expected part of being a Web developer, the same is true for Ajax. Yes, this means that Web developers have yet another set of technologies to learn if they want to keep up.
After several years in which Web developers dealt with incompatible versions, Netscape had the language standardized by the European organization ECMA. Officially, the language is now known as ECMAScript, but no one really calls it that. The versions in Internet Explorer and Mozilla are now largely compatible with the standard, although there are still differences and issues to work around.
Perhaps the simplest way is to create a button—an <input> type meant for exactly this task—and have that button then execute our code. For example:
There is a variety of handlers, all of which begin with the letters “on”, so you can execute a function when someone clicks (onclick), when something is changed (onchange), when an element gets the mouse focus (onfocus) or loses it (onblur), and a number of other possibilities. (Because we're using XHTML, all attributes must be in lowercase. So although it might be tempting to make the event handler more legible by writing onClick, that will invalidate the page.)
We can make this a bit more interesting by personalizing the message:
Practical Task Scheduling Deployment
One of the best things about the UNIX environment (aside from being stable and efficient) is the vast array of software tools available to help you do your job. Traditionally, a UNIX tool does only one thing, but does that one thing very well. For example, grep is very easy to use and can search vast amounts of data quickly. The find tool can find a particular file or files based on all kinds of criteria. It's pretty easy to string these tools together to build even more powerful tools, such as a tool that finds all of the .log files in the /home directory and searches each one for a particular entry. This erector-set mentality allows UNIX system administrators to seem to always have the right tool for the job.
Cron traditionally has been considered another such a tool for job scheduling, but is it enough? This webinar considers that very question. The first part builds on a previous Geek Guide, Beyond Cron, and briefly describes how to know when it might be time to consider upgrading your job scheduling infrastructure. The second part presents an actual planning and implementation framework.
Join Linux Journal's Mike Diehl and Pat Cameron of Help Systems.
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|The Firebird Project's Firebird Relational Database||Jul 29, 2016|
|Stunnel Security for Oracle||Jul 28, 2016|
|SUSE LLC's SUSE Manager||Jul 21, 2016|
|My +1 Sword of Productivity||Jul 20, 2016|
|Non-Linux FOSS: Caffeine!||Jul 19, 2016|
|Murat Yener and Onur Dundar's Expert Android Studio (Wrox)||Jul 18, 2016|
- The Firebird Project's Firebird Relational Database
- Stunnel Security for Oracle
- My +1 Sword of Productivity
- Non-Linux FOSS: Caffeine!
- Managing Linux Using Puppet
- SUSE LLC's SUSE Manager
- Murat Yener and Onur Dundar's Expert Android Studio (Wrox)
- Doing for User Space What We Did for Kernel Space
- Google's SwiftShader Released
- SuperTuxKart 0.9.2 Released
With all the industry talk about the benefits of Linux on Power and all the performance advantages offered by its open architecture, you may be considering a move in that direction. If you are thinking about analytics, big data and cloud computing, you would be right to evaluate Power. The idea of using commodity x86 hardware and replacing it every three years is an outdated cost model. It doesn’t consider the total cost of ownership, and it doesn’t consider the advantage of real processing power, high-availability and multithreading like a demon.
This ebook takes a look at some of the practical applications of the Linux on Power platform and ways you might bring all the performance power of this open architecture to bear for your organization. There are no smoke and mirrors here—just hard, cold, empirical evidence provided by independent sources. I also consider some innovative ways Linux on Power will be used in the future.Get the Guide