On Allyn’s Adventures With Unicorns

It all began last year, on April Fool’s Day.

As a longtime WordPress user, I frequently visit Planet WordPress, an aggregation blog of a number of top WordPress-specific blogs.

And on April Fool’s Day, there was a post from the Gravatar blog on a new gravatar algorithm — Unicorns.

A gravatar, for those unfamiliar with the term, is a little graphic that represents the author of a comment, provided by gravatar.com. It’s a free service; you set up an account, and wherever you post on the ‘net that uses the Gravatar service (as many WordPress-powered sites do), you maintain a consistent visual identity. And for people who haven’t signed up for the service, there are plugins that produce something other than a default image, keyed to the e-mail address. I used one that made goofy faces called Wavatar.

And now, there was a new service — Unicornify!. People could have sparkles and unicorns and rainbows as their avatars.

Naturally, since it was April Fool’s Day, of course. 🙂

(If you want to see what your Unicorn avatar would look like, click here for the test page.)

WordPress guru Otto42 wrote a plugin that took advantage of the unicorn gravatar service, Unicornify.

Since I like to tinker with my WordPress install, I downloaded the Unicornify plugin and installed it. It works by tapping into a WordPress hook; when a gravatar is called, instead of using the Gravatar service, the gravatar will be generated from the Unicornify service.

But I noticed something.

Because of the way the plugin worked, if someone had a registered gravatar, they wouldn’t see it. They would see, instead, the Unicorn gravatar.

Well! I decided that simply wouldn’t do. I don’t want to lose my Charles Schulz-esque Fourth Doctor gravatar on my own website, after all. And so I deactivated the plugin.

That said, I had a pretty awesome unicorn gravatar, if I do say so myself. Rainbows!

Last weekend, I did some clean-up on my WordPress install, deleting some old plugins that I no longer needed.

I’d forgotten about Unicornify. I activated it, just for kicks, and then I wondered if, perhaps, I could make the plugin work the way I wanted it to work — generate a unicorn avatar for people without registered gravatars, but use the registered gravatar for those who have them.

I couldn’t see why this wouldn’t be doable.

I studied up on the WordPress codex; the Using Gravatars article had some code for testing whether or not a gravatar is registered with the Gravatar service that would be useful:

function validate_gravatar($email) {
     // Craft a potential url and test its headers
     $hash = md5($email);
     $uri = 'http://www.gravatar.com/avatar/' . $hash . '?d=404';
     $headers = @get_headers($uri);
     if (!preg_match("|200|", $headers[0])) {
           $has_valid_avatar = FALSE;
     } else {
          $has_valid_avatar = TRUE;
     }
     return $has_valid_avatar;
}

The Unicornify plugin builds a URL to http://unicornify.appspot.com, and the Unicorn avatar link is built in exactly the same way that a link to gravatar.com is built. It occurred to me that if I tested the e-mail address that is passed through Unicornify to see whether or not a gravatar linked to that account exists, then I could determine which gravatar to call — the registered gravatar or the unicorn gravatar.

Genius!

So, I dropped that validate_gravatar function into the plugin, then wrote some code. Instead of the line:

     $host = 'http://unicornify.appspot.com';

I would do this:

     $registered_gravatar = validate_gravatar ( $email );

     if ( $registered_gravatar ) {
          $host = 'http://www.gravatar.com';
          $alt = 'Registered Gravatar';
     } else {
          $host = 'http://unicornify.appspot.com';
          $alt = 'Unicorn Gravatar';
     }

As genius as this was…

It didn’t work.

It should have worked. But some PHP config settings in my webserver were preventing it from working, and since I couldn’t change those, I wondered if I might be able to find a workaround.

The problem, as it turns out, was the get_headers function. It simply would not work with my server, probably due to the way that my webserver was upgraded from PHP4 to PHP5.

So, I turned to the source of all knowledge — the Internet. 😉

And, at php.net, I found a workaround. In their article on the get_headers function, there were several workaround functions posted for pre-PHP5 servers. My server, I should note, is, in fact, a PHP5 server. But I thought the workaround might be a good solution, and so I dropped the code for one of those workarounds into the Unicornify plugin.

Lo and behold, it worked!

I made another change to the code. I eliminated the validate_gravatar function entirely, and instead integrated it into the unicornify function. There was no need to hash the e-mail address a second time; the Unicornify code already did that. The result was some simpler, less redundant code, and the result was this:

     $uri = 'http://www.gravatar.com/avatar/' . $email_hash . '?d=404';
     $headers = @get_headers($uri);
     if (!preg_match("|200|", $headers[0])) {
          $host = 'http://unicornify.appspot.com';
          $alt = 'Unicorn Gravatar';
     } else {
          $host = 'http://www.gravatar.com';
          $alt = 'Registered Gravatar';
     }

Until I get tired of it then — probably by Mid-Year’s Day — I’ll have unicorn gravatars for people who leave comments! Leave a comment and you’ll see your own colorful unicorn. 🙂

For WordPress junkies who want the complete code, here’s the modified plugin. Use at for your own peril fun! :h2g2:

Sparkles! Rainbows! Unicorns!