Let’s assume that the database migration should take place when the plugin is activated. Assuming your plugin is named myplugin, put this code in the myplugin.php file:

register_activation_hook(__FILE__, 'myplugin_install');

This makes WordPress execute the myplugin_install() method when the user activates your plugin.

Next, add this method:

function myplugin_install() {
  myplugin_migrate();
}

And our migration method:

function myplugin_migrate() {
  global $wpdb;

  $migs = myplugin_migrations();

  $current_migration = get_option('myplugin_current_migration', 0);
  $needed_migration = count($migs);

  for ($i = $current_migration; $i < $needed_migration; $i++) {
    $mig = $migs[$i];
    $wpdb->query($mig);
  }

  if ($current_migration == 0) {
    add_option('myplugin_current_migration', $needed_migration);
  } else {
    update_option('myplugin_current_migration', $needed_migration);
  }
}

What this does is that it runs through database statements (queries) returned from the myplugin_migrations() method. Let’s implement the actual migrations – add this method:

function myplugin_migrations() {
  global $wpdb;

  $migs = array();

  // Create example table
  $migs[] = '
  CREATE TABLE '.$wpdb->prefix.'myplugin_examples (
    id int(11) NOT NULL AUTO_INCREMENT,
    name varchar(255) NOT NULL,
    PRIMARY KEY (id)
  )';

  // Add examples
  $migs[] = "INSERT INTO ".$wpdb->prefix."myplugin_examples SET name='First example'";
  $migs[] = "INSERT INTO ".$wpdb->prefix."myplugin_examples SET name='Second example'";

  // Return the migrations
  return $migs;
}

That would create an example table and insert some values.

Now imagine that two months later you need a description field in your examples table. What do you do? It’s as easy as adding one line of code to the migrations:

// Add description field to examples
$migs[] = "ALTER TABLE ".$wpdb->prefix."myplugin_examples ADD description VARCHAR( 255 ) NOT NULL";

Deactivate and activate the plugin, and you table now has an extra field. Easy as cake!

Share your thoughts, opinions, and suggestions below.

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Visit the plugin page: A/B Test for WordPress

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Let’s say you have a blog and you have been using the standard WordPress Twenty Eleven theme for a while but now you saw this great looking theme that’s just a must have. How do you find out if this new theme will make your site perform better or worse, and how will it affect outbound link clicks to your new book at Amazon? Let’s find out

WordPress comes with the Twenty Eleven theme, so we’ll split test between this and another theme. Let’s install the free Adventure Journal theme:

For information on how to install themes, visit Using Themes on the WordPress site.

Then intall the plugin and activate it in Plugins:

Click the A/B Testing link right below Settings:

Click Create new experiment:

Enter “Split testing my theme” as Name and select Theme as Experiment type:

Click Create experiment.

Click Edit below Experiment 1:

Select the Adventure Journal theme:

Click Update variation.

Do the same for Variation 2 where you select Twenty Eleven as the theme.

Click Back to experiments at the bottom of the page:

Now we’re going into Debug mode to test our variations. About the Debug mode:

“Normally, when a user first sees a variation to an experiment, this variation is locked for this user so that – in this session – she always sees the same variation.
If you want to test your experiments without this variation lock taking place for you (and only you), you can enable debug mode. Also, when entering debug mode, all tracking will be disabled for your session.”

Click Enter debug mode in the top right corner of the screen:

Debug mode is now on:

Now go to the front page of your site, and you’ll see one of the themes being displayed:

Now click Refresh a couple of times, and you’ll see that the theme changes:

Neat, eh?

Back into the admin interface, click Exit debug mode:

We’ll now set up a link and track when this link is clicked. We’ll use a link to a book on Amazon to simulate an author site with a “Buy my book” link.

Click Split testing my theme and scroll down to Goals:

Click Get tracking code right below Goal 1 and you’ll see this screen:

Select the javascript code below To track a link and copy it to the clipboard using CMD + C (on a Mac) or CTRL + C (on a PC):

We’ll now create a widget with our link to Amazon.

Click Appearance and then Widgets in the menu to the left:

Insert a widget by dragging a Text box from the Available Widgets box:

Onto the Main Sidebar on the right:

Enter “Buy my book” as Title and insert this code below:

<a href="http://www.amazon.com/WordPress-Power-Guide-Blogging-ebook/dp/B004UW29IK/ref=sr_1_1?ie=UTF8&qid=1326554345&sr=8-1" onclick="abtest.trackGoal(1, this);">Buy my book on Amazon</a>


Like this:

Notice how we’re using the onclick="abtest.trackGoal(1, this);" code? That’s what’s tracking our link when we click it.

Click Save.

Now go back onto the front page and you’ll see that the widget has been inserted into your site:

So far so good.

Try clicking the link.
You have now tracked a goal completion!

Back into the admin interface, click on the experiment and you’ll see that it has tracked a goal completion:

Nice! Now you just need to wait and see which theme performs better.

For more info, installation instructions, and tutorials, visit the A/B Test for WordPress plugin page.

Also, please feel free to contact me if you have any questions.

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Visit the plugin page for more information, download, tutorials, and videos.

Here is a video introduction:

→ Download the plugin (or see more information)

Please feel free to contact me if you have any questions.

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I bought my MacBook on May 1th after viewing a screencast where a guy sets up a blog in 15 minutes using Ruby on Rails. I immediately said to my stepdad: “I’m going to buy a Mac and learn Ruby on Rails!”

And so I did – the day after, I bought a Mac.

I’ve always been a dedicated user of Microsoft‘s products. First C64, then Amiga, then Mac, then PC. I liked the way everything was tested and came from one place, unlike open source. I’ve always been saying stuff like “I like to pay for my software because then I’m be sure about the quality.” – but in reality, everyone who uses Windows and other Microsoft products know that this isn’t always the case.

So I bought the Mac, and the first thing that surprised me, was how much of day-to-day work was done in the Terminal, or command line. When I installed Ruby on Rails, it was via command line; when I installed plugins, it was via command line. Evererything command line.

Over the next few days I began to get a hang of it. I bought a couple of domain names and signed up for a slice at Slicehost – because I had read some job description that said that you should’ve at least tried to use a whole day of setting a slice.

Coming from Windows, Linux is a whole other deal to setup. I used a lot of the Slicehost articles that guides you through the whole process from setup and security to getting your slice to run as a webserver.

In the beginning I was a little nervous about all the command lines, if they would really work and so one. But the more you try it, the more calm you get. It just works! And lucky me there was a lot of helpful articles about Unix and Linux commands out there (just search for the command on Google).

Since starting out on the Mac, I’ve learned a multitude of things:

• Setting up an Ubuntu slice at Slicehost.
• Setting up a web server.
• Setting up Ubuntu Netbook Remix on my netbook.
• Setting up Ubuntu server at home, also on my netbook – which now functions as my testing server.
• Programming a little PHP – see Tweet My Cam.
• Programming Ruby on Rails.
• Tweaking some Java code, compiling and signing a java applet in one day – see a demo here.
• Download and compile software (configure, make, make install).
• Submitted a patch to a Ruby on Rails plugin on Github.
• Setting up WordPress and WordPress Mu blogs and making my own theme – see my private blog and private work blog.
• Setting up a Subversion repository at XP-Dev.com.
• Using the Subversion repository
• Loving Textmate as my favorite editor – also over Visual Studio.
• Plus a bunch of other things.

In short I’ve learned so much about the open source world that just wasn’t that easy on the Microsoft platform.

I still use Microsoft Windows and other products, but now it’s through VMware Fusion on the Mac.

I’m happy about the Mac because OS X is very unobtrusive, fast operating system and what it does, it does very good. But at the same time, I also want a netbook that’s easier to carry, so I may end up running both systems for different purposes (unless I’m just installing Ubuntu on the netbook too ).

Hope you found this post interesting – I wrote it to tell about a beautiful (yak, I know) progress from Windows to Mac and Linux. Thumbs up if this has made you want to try it too. And please tell me in the comments.

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