Function Archive

Remove the WWW Prefix for all URLs via PHP

Posted on February 8, 2009 in Function by Jeff Starr

Canonical URLs are important for maintaining consistent linkage, reducing duplicate content issues, and increasing the overall integrity of your site. In addition to cleaning up trailing slashes and removing extraneous index.php and index.html strings, removing the www subdirectory prefix is an excellent way to shorten links and deliver consistent, canonical URLs.

Of course, an optimal way of removing (or adding) the www prefix is accomplished via HTAccess canonicalization:

Eight Ways to Blacklist with Apache’s mod_rewrite

Posted on February 3, 2009 in Function by Jeff Starr

With the imminent release of the next series of (4G) blacklist articles here at Perishable Press, now is the perfect time to examine eight of the most commonly employed blacklisting methods achieved with Apache’s incredible rewrite module, mod_rewrite. In addition to facilitating site security, the techniques presented in this article will improve your understanding of the different rewrite methods available with mod_rewrite.

Blacklist via Request Method

[ #1 ] This first blacklisting method evaluates the client’s request method. Every time a client attempts to connect to your server, it sends a message indicating the type of connection it wishes to make. There are many different types of request methods recognized by Apache. The two most common methods are GET and POST requests, which are required for “getting” and “posting” data to and from the server. In most cases, these are the only request methods required to operate a dynamic website. Allowing more request methods than are necessary increases your site’s vulnerability. Thus, to restrict the types of request methods available to clients, we use this block of Apache directives:

Unobtrusive JavaScript for ‘Print-This’ Links

Posted on February 1, 2009 in Function by Jeff Starr

One of the oldest JavaScript tricks in the book involves providing a “print this!” link for visitors that enables them to summon their operating system’s default print dialogue box to facilitate quick and easy printing of whatever page they happen to be viewing. With the old way of pulling this little stunt, we write this in the markup comprising the target “print this!” link in question:

<a href="javascript:window.print()">Print This!</a>

Big yuck there, of course, due to the obtrusive nature of the JavaScript implementation. Adhering to the principles of proper Web Standards, it is better practice to separate behavior from structure by placing this amazing “print this!” function in its own location, either in the <head> of the document or even better in an external JavaScript file. So basically, we want markup that looks more like this:

<a href="http://domain.tld/target/" title="Print this page">Print This!</a>

Notice the new value for the href attribute. Rather than pointing illogically to the JavaScript function, it now points to an actual resource, which may be anything you desire. Previously, users without JavaScript would click the “print this!” link and blink while nothing happens. With the unobtrusive technique, you provide the location to which users without JavaScript shall go. Possibilities here include an explanation page or even just the page itself, depending on how lazy you wanna be.

PHP and JavaScript Fallbacks for Your Public Feedburner Count

Posted on January 25, 2009 in Function by Jeff Starr

With the recent Feedburner service outage, many sites across the Web experienced severe drops in their Feedburner subscriber counts. Apparently, Google is requiring all Feedburner accounts to be transferred over to Google by the end of February. In the midst of this mass migration, chaotic subscriber data has been reported to include everything from dramatic count drops and fluctuating reach statistics to zero-count values and dreaded “N/A” subscriber-count errors. Obviously, displaying erroneous subscriber-count data on your site is not a good thing. Fortunately, there are several ways to ensure that this doesn’t happen.

Over at CSS Newbie, author Rob Glazebrook weighs in with an excellent point about covering your bases when displaying your Feedburner subscriber count. As explained in the article, Feedburner’s handy API makes it easy to tap your data and display your subscriber count on your blog. Despite its best intentions, however, Feedburner occasionally returns inaccurate data or even no data at all for the subscriber count. For those of us who care about the accuracy of our publicly displayed feed statistics, displaying information like this on your site is simply unacceptable:

Targeting External Links Intelligently

Posted on January 20, 2009 in Function by Bill Brown

In the beginning…

[ Young Planet Earth ] In the time of the dinosaurs, HTML authors controlled the way anchors opened by adding target="_blank" as an attribute on an anchor tag. Then the molten mass of Internet began to cool into the thin crust of Web 2.0, the continents began to separate and there came a great migration of pages from HTML to the shinier, new XHTML. Most authors didn’t know what that meant, but it had an “X” in it, so it must be cool, they thought.

Alas, there came a great despair as the beloved target="_blank" attribute was no longer looked kindly upon by The Great Validator. The new XHTML pages would not wear the Shiny Badge of Validation Love.

Temporary PHP Redirect: Allow Multiple IP Access and Redirect Everyone Else

Posted on January 14, 2009 in Function by Jeff Starr

[ Image: Abstract Mathematical Diagram ] In my previous article on temporarily redirecting visitors during site updates, I present numerous PHP and HTAccess methods for handling traffic during site maintenance, updates, and other temporary periods of downtime. Each of the PHP methods presented in the article allow for access from a single IP while redirecting everyone else. In this article, we modify our previous techniques to allow access for multiple IP addresses while temporarily redirecting everyone else to the page of our choice. Plus, while we’re at it, we’ll explore a few additional ways to adapt and use the general technique.

PHP Short Open Tag: Convenient Shortcut or Short Changing Security?

Posted on January 12, 2009 in Function by Bill Brown

[ Echo Shortcut Code ] Most of us learned how to use “echo()” in one of our very first PHP tutorials. That was certainly the case for me. As a consequence, I never really had a need to visit PHP’s documentation page for echo(). On a recent visit to Perishable Press, I saw a Tumblr post from Jeff about the use of PHP’s shortcut syntax for echo() but somewhere deep in my memory, there lurked a warning about its use. I decided to investigate.

New and Improved JavaScript Clock

Posted on January 4, 2009 in Function by Jeff Starr

Earlier this year, I posted an article explaining how to implement an unobtrusive JavaScript dynamic clock. While not completely earth-shattering or cutting-edge or anything like that, the dynamic JavaScript clock has received some great feedback from users who found the script to be exactly what they were looking for. In fact, a couple of weeks ago, Bill Brown went above and beyond by taking the time to improve the script with some great new features, including a “blinking seconds separator (for kicks)” and removal of “the need for the noscript tag.” Here is the complete script sent by Bill in a recent email (with slightly reformatted markup). To try it out, simply copy and paste the following code into a blank PHP document (no editing required!):

Redirect All (Broken) Links from any Domain via HTAccess

Posted on December 31, 2008 in Function by Jeff Starr

Here’s the scene: you have been noticing a large number of 404 requests coming from a particular domain. You check it out and realize that the domain in question has a number of misdirected links to your site. The links may resemble legitimate URLs, but because of typographical errors, markup errors, or outdated references, they are broken, leading to nowhere on your site and producing a nice 404 error for every request. Ugh. Or, another painful scenario would be a single broken link on a highly popular site. For example, you may have one of your best posts mentioned in the SitePoint forums, but the person leaving the link completely botched the job:

Unobtrusive JavaScript: 5 Ways to Remove Unwanted Focus Outlines

Posted on December 16, 2008 in Function by Jeff Starr

I recently wrote about how to remove unwanted link outlines using a pure-CSS method that works on every modern browser except (wait for it) ..Internet Explorer 6! Yes, that’s right, another reason why (almost) everyone is pushing hard to eliminate Internet Explorer from existence.

Nonetheless, removing those pesky unwanted link outlines in IE6 is not possible with CSS, but it’s a snap with a little JavaScript. Here are four unobtrusive JavaScript techniques (plus one CSS-only method thrown in for good measure) for removing unwanted focus outlines.

Custom OpenSearch Functionality for Your Website

Posted on December 7, 2008 in Function, Websites by Jeff Starr

I recently added OpenSearch functionality to Perishable Press. Now, OpenSearch-enabled browsers such as Firefox and IE 7 alert users with the option to customize their browser’s built-in search feature with an exclusive OpenSearch-powered search option for Perishable Press. The autodiscovery feature of supportive browsers detects the custom search protocol and enables users to easily add it to their collection of readily available site-specific search options. Now, users may search the entire Perishable Press domain with the click of a button.

And you can do it too! Adding customized OpenSearch-powered search functionality to your own site is a great way to foster site awareness and reinforce brand identity, while providing a tool that will benefit your visitors and improve the usability of your site. Even better, implementing OpenSearch functionality is extremely easy, completely free, and requires zero maintenance. In this article, I provide an easy, 3-step tutorial on how to add OpenSearch functionality to your site in less than five minutes. After the tutorial, we will look at the many different ways to customize your OpenSearch implementation, including examples, search options, and much more.

Redirect any Subordinate URL to its Parent Directory via PHP

Posted on November 26, 2008 in Function by Jeff Starr

Simple one for you today. After posting on how to use HTAccess to redirect subordinate URLs to the root (or parent) directory, I thought I would share an alternate way of accomplishing the same trick using PHP. Fortunately, using this PHP redirect technique doesn’t require access to or fiddling with your site’s HTAccess (or Apache configuration) file and it is very easy to implement.

The scene, as discussed in greater detail in my previous article on this topic, involves a very specific type of redirect whereby some target URL is redirected up the directory structure to one of its parent directories. Redirecting such subordinate content generally falls into one of two categories:

Save Bandwidth by Serving jQuery, MooTools, Prototype via Google’s AJAX Libraries API

Posted on November 25, 2008 in Function by Jeff Starr

A great way to save bandwidth is to take advantage of Google’s AJAX Libraries API to serve your favorite open-source JavaScript libraries. Here is how Google explains it in their official documentation:

The AJAX Libraries API is a content distribution network and loading architecture for the most popular open source JavaScript libraries. By using the google.load() method, your application has high speed, globally available access to a growing list of the most popular JavaScript open source libraries.

The Ultimate Guide to swfIR Image Replacement

Posted on November 9, 2008 in Function, Presentation by Jeff Starr

[ Screenshot: Example Photo Styled with swfIR ] In this ultimate guide to swfIR, you will learn how to use swfIR to replace your ordinary images with richer, stylized graphics. swfIR enables efficient, practical and scalable application of drop-shadows, rounded corners, and even image rotation to any number of specified images throughout your site. From concept and application to examples and recipes, this guide covers everything you need for successful swfIR implementation.

The Challenge..

There are many ways to enhance the visual presentation of your images. Popular visual effects include rounded corners, drop shadows, and image rotation. To achieve these effects, designers often use either CSS, direct image manipulation, or some combination thereof. CSS may possess limited ability to round image borders in certain browsers, but for drop shadows and image rotation, designers must either modify each image individually, or rely upon convoluted techniques employing additional graphics and CSS to get the job done. This may be suitable for a single header graphic, but for any significant number of images, hand-editing each one in Photoshop with the desired visual effect is neither efficient, practical, nor scalable.

Better Default Directory Views with HTAccess

Posted on November 2, 2008 in Function by Jeff Starr

[ Screenshot: Default Directory View ] Beautify your default directory listings! Displaying index-less file views is a great way to share files, but the drab, bare-bones interface is difficult to integrate into existing designs. While there are many scripts available to customize the appearance and functionality of default directory navigation, most of these methods are either too complicated, too invasive, or otherwise insufficient for expedient directory styling. In this comprehensive tutorial, you will learn how to use the built-in functionality of Apache’s mod_autoindex module to style and enhance your default directory views with a smorgasbord of stylistic and functional improvements.

Blacklist Candidate 2008-10-19

Posted on October 19, 2008 in Function by Jeff Starr

Welcome to the Perishable Press “Blacklist Candidate” series. In this post, we continue our new tradition of exposing, humiliating and banishing spammers, crackers and other worthless scumbags..

[ Photo: Television Flashback ] From time to time on the show, a contestant places a bid that is so absurd and so asinine that you literally laugh out loud, point at the monitor, and openly ridicule the pathetic loser. On such occasions, even the host of the show will laugh and mock the idiocy. Of course, this same situation happens frequently here at Perishable Press, where the scumbags that manage to escape the 3G Blacklist are proving themselves to be increasingly desperate and pathetic. Such is the case with this month’s official Blacklist Candidate Number 2008-10-19:

Come on down — you’re the next cracker whore to get banished from the site!

Redirecting Subdirectories to the Root Directory via HTAccess

Posted on October 6, 2008 in Function by Jeff Starr

One of the most useful techniques in my HTAccess toolbox involves URL redirection using Apache’s RedirectMatch directive. With RedirectMatch, you get the powerful regex pattern matching available in the mod_alias module combined with the simplicity and effectiveness of the Redirect directive. This hybrid functionality makes RedirectMatch the ideal method for highly specific redirection. In this tutorial, we will explore the application of RedirectMatch as it applies to one of the most difficult redirect scenarios: redirecting all requests for a specific subdirectory (or any subordinate directory or file) to the root (or any parent) directory. We will explore how to accomplish this redirect using PHP in a subsequent article.