Felix Geisendorfer has a quick little sorting example posted today showing on way to sort a multi-dimensional array.

Quick challenge, lets say you have an array and you want to iterate through your products by [the key of each subarray in $products] Product.ordering ASC. Whats the fastest way to do this?

His solution involves using an array_flip call on the extracted information (using Set::extract), ordering it with ksort and pushing the values back into the $product array in the right order.

Check out the comments for more examples including ones that make use of array_multisort.

Gareth Heyes has posted another challenge to his blog - this time it involves using a regular expression to convert the inputted string into the output he's given.

After the success of my "a bit of fun" challenge, a few people asked for some more challenges. So I was answering a question on a mailing list that I'm a member of and I thought it would be a good topic for a little challenge and help sharpen everyone's regular expression skills.

This time, his challenge involves taking the input, rail start/end locations from an array and, via the PHP script given (no regular expression in it, of course) make the output, a sort of JSON formatted message. It's already been answered, but if you want to, try it yourself first then read the answer below the post.

On The Bakery blog, there's a new article introducing dAuth:

The authentication (not authorization) system with a focus on security, using techniques such as challenge-response, customizable multiple-stage password hashing, brute force (hammering) detection etc.

The dAuth system is based around a challenge-reponse authentication system and handles ensuring the user is who they say that are, but not that they're authorized to be looking at what they see.

They include a graphic to help explain how the process flows and some talk about the changes made from some of the previous versions including detection of brute-force attempts, preventing the disabling of the fallback, and session hijacking compensation.

There's some brief bits about the installation of the tool and some final words to shove you in the right direction.

Ruzz has started up a new blog over off of Lifelogger.com that looks to take a more in-depth look at one of the more popular PHP-based frameworks offered today, symfony.

In this first post, specifically, he talks about his opinions on why symfony is worth the trouble, who he is to talk about it, and what kind of things you can expect from the blog in the future. He's also providing a running report of something he's calling the "symfony challenge" - a commentary of his complete rewrite of an application he previously wrote with a framework of his own making.

In this new post from the SitePoint PGP Blog today, Harry Fuecks mentions some of Tim Bray's considerations of putting commenting into his site and some of the technological implications of it.

Harry also looks, on the same topic, at some PHP-related issues dealing with commenting in an application, including:

• Do we recommend Tim use a forms library? E.g. QuickForm or Patforms?
• For authentication OpenID seems to be on it's way to becoming a serious contender...
• A design somewhere in the realm of Rasmus's no-MVC MVC
• For the XML generation he mentions, DOM or SimpleXML (which implies PHP 5.x+)?