At the Forge - Dojo Events and Ajax
We can then tell the user's browser to invoke our openAlert function whenever someone clicks on a paragraph of text:
<p onclick="openAlert();">This is a paragraph.</p>
Second, event handlers sometimes can be used in contexts you might not expect. For example, the above <p> tag has an onclick handler. You normally wouldn't think of clicking on a paragraph of text, but we can do that. This is the basis for some of the modern drag-and-drop events.
As a simple example, let's see how we might implement our onclick handler from before using Dojo events. First, we need to modify our event-handling function so that it takes one argument, the event itself:
Next, we must connect the paragraph to the event. Rather than doing this directly, by setting the onconnect handler, we give our paragraph an id tag:
<p id="para">This is a paragraph.</p>
Now, we can use Dojo's dojo.byId function—similar in some ways to Prototype's $() function—to get the node itself:
var para = dojo.byId("para");
Finally, we connect our paragraph to the handler function we created:
dojo.event.connect(para, "onclick", openAlert);
If we put it all together, we get the program shown in Listing 1, which I have called test-dojo.html.
Listing 1. test-dojo.html
If you load the page into a browser window, you will see that it works just like the previous version. Given that this version is more complex, it might not seem obvious how it is better.
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)
- Google's SwiftShader Released
- SuperTuxKart 0.9.2 Released
- Doing for User Space What We Did for Kernel Space
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