A Database-Driven Web Application in 18 Lines of Code
Restart Apache before accessing the Maypole application:
service httpd restart
I entered http://webmason.itcarlow.ie/Club/ into the Firefox location bar, and up popped Figure 1, which, although something, was not quite what I was expecting.
For starters, I was expecting to see some nice CSS output, not the plain HTML I was seeing. To fix this problem, I explored the default template files copied into the Web server during Step 6. By changing these, it is possible to alter the appearance of the application, without changing the source code to the application. The significance of that last sentence cannot be overstated. In essence, the way the application looks is controlled by the CSS templates. The way the application behaves is controlled by the code. The data used by the application is controlled by MySQL. All of this separation of duties makes for a very productive development environment, as changing one part of the application shouldn't adversely affect either of the others.
The templates live within a subdirectory called factory, located beneath the URL of the application, which is Club/ in this case. The factory templates are the Maypole defaults and are used unless overriding templates are found within another directory, called custom.
After creating the custom directory underneath the Club/ URL, I copied the header file from factory to custom and edited it with vi. I changed /maypole.css to read /club.css, in addition to replacing the “A poorly configured” message with a more appropriate description of the application. I also copied the frontpage file from factory to custom and edited it to use a better application description. Then, I changed the anchor tag within custom/frontpage to read “Work with the player data” as opposed to the default “List by player” text. With these changes made, I clicked the Reload button within Firefox, resulting in Figure 2, which—I think you'll agree—looks a whole lot better.
Clicking on any of the menu options produces a beautifully formatted input screen, like those shown in Figures 3 and 4.
Figure 4 shows the display after the entry of two fictitious players. Notice all the functionality provided for free. Tabs for each of the tables are located along the top of the display. Simply click on the tab to display that table's data. Each row of data has an associated edit and delete button. Click on any column heading to sort the display on the data in that column. Perform a search using the provided search form. Add more players using the add form. Notice the drop-down menus for the player's squad and medical condition. Click on the field and a drop-down box appears with the choices available to you. This bit of magic occurs because Maypole has been told that each player “has a” squad and “has a” condition. By default, Maypole uses the name data column in the referred to table to provide the data to these drop-down boxes.
And, that's it—a fully functioning Web interface to an underlying database, in eight easy steps.
Despite the fact that Maypole is quite new, an active community already has gathered around it. The mailing list recently split, one for developers and the other for users, and the Maypole Web site is now hosted by perl.org.
As I hope I've demonstrated, Maypole—once set up—is a breeze to use. Most of the guts of any Web application is provided for free. Adding additional functionality also is possible. Maypole is not stuck on MySQL either, as any SQL DBMS can be used. Refer to the articles and documentation referenced on the Maypole site for more details.
Resources for this article: /article/7964.
Practical Task Scheduling Deployment
July 20, 2016 12:00 pm CDT
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.
Free to Linux Journal readers.Register Now!
- SUSE LLC's SUSE Manager
- My +1 Sword of Productivity
- Murat Yener and Onur Dundar's Expert Android Studio (Wrox)
- Non-Linux FOSS: Caffeine!
- Managing Linux Using Puppet
- Doing for User Space What We Did for Kernel Space
- Tech Tip: Really Simple HTTP Server with Python
- Parsing an RSS News Feed with a Bash Script
- SuperTuxKart 0.9.2 Released
- Rogue Wave Software's Zend Server
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