As a programmer/web-designer I dip into a diverse range of programming languages and frameworks. I often find that I get locked into a specific coding grammar/syntax and that it is then difficult to switch to a new one. This is when I find the following cheat sheets invaluable (and indeed comforting).

• Subversion (SVN) - 293 KB PDF
• Regular Expressions (RegEx) - 648 KB PDF
• mod_rewrite - 563 KB PDF
• PHP - 556 KB PDF
• CSS - 316 KB PDF
• HTML - 563 KB PDF
• Ruby On Rails - 753 KB PDF
• HTML Character Entities - 959 KB PDF
• JavaScript - 453 KB PDF
• MySQL - 348 KB PDF
• RGB Hexadecimal Colour Chart - 199 KB PDF
• OS X / Linux / Unix
• Photoshop CS3

Due to work and other commitments it’s been a while since I last posted here. In the meantime my RSS client periodically trawled the great ocean of the Internet and landed a rather decent catch of prime linkage. So, without further ado, I present a link anthology - the very best that’s passed before my radar over the last week or so.

Apple

• In “Steve Jobs and the Portal to the Invisible” Tom Junod becomes the latest in a long line of journalists to explore the enigma that is Steve Jobs — with a slightly macabre slant.
• Apple Publications Style Guide 2008 (2 MB PDF) and don’t be fooled into thinking that this is only relevant to the Apple audience!
• Leopard’s “Stacks” are a great addition to OS X but the dock icon handling is, ahem, shitty (sorry Apple). Stu Greenham provides a little cosmetic overhaul.

Art & Design

• 35 Beautiful Grunge Website Designs You May Not Have Seen Before.
• Is your website’s underwear showing? Remember to specify a background colour.
• ILoveSketch: A 3D curve sketching system that captures some of the affordances of pen and paper for professional designers.
• Behind the Design: 5 Stories of Great Inspiration.

Current Affairs

• The End: The era that defined Wall Street is finally, officially over. Michael Lewis, who chronicled its excess in Liar’s Poker, returns to his old haunt to figure out what went wrong.

Music & Video

• 60 Beautiful Music Videos: The music video is a unique art-form and Smashing Magazine has collected together 60 of the most original in one place. Use Jason Kottke’s “High Quality YouTube Video Hack” to enjoy them more fully.
• King Lines Trailer: Extreme climbing.
• 50 Beautiful Movie Posters: I’ve always loved movie posters and some of these are breathtaking.

Technology

• Gesture Based Control: Mgestyk is a new touch-free way to interact with your computer. It lets you control games and other applications just by moving your hands, allowing for more natural and immersive interaction. Gestures are processed in 3D, meaning that even depth-based gestures (like controlling the throttle of a plane) are natural and responsive to use. Mgestyk works even in total darkness! We eagerly await an OS X version.
• uplog: Freeform R&D.

After reading Ian Lloyd’s The Perfect 404, I’ve revamped my “Not Found” error page to be a little bit more useful because, as Lloyd writes, “a user-friendly website will give you a helping hand.” Previously my 404 page simply stated that an error had occured and offered links to the home-page and archives. I knew I could do better than that!

The simplest change I made was to remove the “404” error code. After all, while you and I understand what this means, my next-door neighbour wouldn’t. To Joe the Plumber this error code is simply redundant information.

I wanted to try to explain why the reader had ended up on the 404 page. So my body text begins with something like:

Sorry, but /[url_fragment]/ doesn’t exist on the Urban Mainframe at this time.

It seemed polite to explain that the error could either be mine (I might have changed a URL or removed a resource) or it could be that a referring link is incorrect. So I needed to determine whether or not there was a referring link and, if there was, I could then display an appropriate message.

The link at http://some-domain.com/bad_referrer/ is incorrect or /[url_fragment]/ has been moved, renamed or deleted.

A snippet of PHP code in my WordPress’ 404 template serviced this requirement:
<?
if ($_SERVER['HTTP_REFERER']) {
echo "<p>The link at <em><a href=\"" . $_SERVER['HTTP_REFERER'] . "\">" . $_SERVER['HTTP_REFERER'] . "</a></em> is incorrect or <em>" . $_SERVER['REQUEST_URI'] . "</em> has been moved, renamed or deleted.</p>";
}
?>
Then I present the reader with a couple of options by providing links to the home-page, the archives and, via Matt Mullenweg’s Random Redirect WordPress plug-in, a link to a random page on the website - just for a bit of fun.

The next bit’s really neat — using a (slightly modified) script I found, WordPress breaks the erroneous URL into its component parts (ditching the domain fragment) and uses those parts as keywords for a full-text search of all my published pages and posts. It then presents the reader with a list of page titles that might be what they were looking for in the first place. Granted, it’s a long shot, but they just might get lucky and, even if they don’t, it exposes them to a selection of my content that they might otherwise have missed.

Updated, 4th November 2008: You may not have full-text indexing configured in your WordPress database. In order for the full-text search to work you’ll first need to issue the following command to MySQL:

ALTER TABLE `wp_posts` ADD FULLTEXT `post_related` (`post_name` ,`post_content`);

To draw the reader’s attention to even more content, I also display a list of my most recent posts with another PHP code snippet:

<h3>Recent Posts</h3>
<ol style="margin-left: 40px;">
<?php $postslist = get_posts('numberposts=5');
foreach ($postslist as $post) :
setup_postdata($post); ?>
<li><a href="<?php the_permalink(); ?>"><?php the_title(); ?></a></li>
<?php endforeach; ?>
</ol>
The options end with a link to my contact form so that the reader can send me an email if further help is required.

Bonus: While I was putting this together, I tried various combinations of URL in order to test the error handler and I discovered something rather neat in the process. If I enter a URL that doesn’t directly match one that’s valid on the Urban Mainframe but that’s similar to another that’s unique, then WordPress automatically redirects to the other rather than respond with a 404. For example, if I enter the non-existant URL http://blog.urbanmainframe.com/insight/ then WordPress automatically redirects to http://blog.urbanmainframe.com/2008/08/insight/ — that’s pretty cool!

It goes without saying that I want as few visitors as possible to see my 404 page but, for those unfortunate souls who do arrive there, I hope that the options available will help them on their way and hopefully keep them on my website longer than they would otherwise have stayed.

What do you think? Is there anything I can do to improve the page further? What’s on your 404 page? Let me know in the comments.

I must confess that I am an addict. I have become addicted to creating computer-generated images. Having recently posted about Processing and Oxidizer, I have found another image generator called “Context Free.”

Context Free “is a program that generates images from written instructions called a grammar. The program follows the instructions in a few seconds to create images that can contain millions of shapes.”

Creating images with the software is a piece of cake. One can download from a gallery of “grammar” files or create your own scripts. Downloaded scripts can have their output modified by entering a three-character code into the Context Free application, leading to millions of permutations of the work.

It’s a fascinating program to play around with and some of the output is simply stunning.

Best of all — the software is free, open-source and is available for Windows, OS X and various flavours of Unix.