Observers and Subjects

The most well-known design pattern for decoupling object instances or classes from one another and still have a mechanism for the observer to know, when a particular event occurs on a subject, is the Observer-Pattern. The implementation is typically done either using abstract classes or using interfaces. While the prior has the advantage that the abstract classes may provide a reusable behaviour for observer registration and notification it limits...

Categories: Featured, Patterns, PHP

Enumerations in PHP

Sometimes you stumble over stuff on the net and really think to yourself. Wow! Why does not everybody talk about it yet? My Subject of the day is Enumerations in PHP via SPL_Types. Basically it brings Enumerations to PHP, ensuring that a variable may only contain specific values based on a value domain. This should be looking something like this. class Weekday extends SplEnum { const Sunnday = 0; const Monday = 1; const Tuesday = 2; const Wednesday = 3; const Thursday = 4; const Friday = 5; const Saturday = 6; const __default...

Categories: PHP

Validating user input using PECL::filter

PECL::filter is a new promising PHP extension, which will come with the new PHP 5.2.0. It is mainly meant for validation of input, which currently requires quite some work. Since there is no documentation over at php.net you can read all about it over here. For all the guys using Windows for your development environment here you can download the compiled extension for your current PHP installme...

Categories: PHP

Calculating distances

Since I seem to have a fav on geo-calculation since Google-Maps has hit me, I have been looking for some information how to calculate distances between to points on the globe. The GoogleAPI actually has a method to calculate the distance between points based on a shperical model. But what if you'd like to implement a radius search on the database or calculate distances on the backend. I found a nice introduction for the subject over at MeridianWorldData,...

Categories: API, Featured, PHP

Mashup GoogleMaps and GeoIP

Ok I have put together a small example of how to use GoogleMaps and GeoIP. Use it to look up where a specific URL or server is hosted. You can view it here. The application includes a bookmarklet, which you may bookmark or place in the link's bar of your browser to use it from every website to determine it's location. For all you PHP freaks, you can download the complete example as well. Just unpack the ZIP file on your PHP5-enabled server and you should be good to go. Just make sure to use your own GoogleMaps API key, you can get he...

Categories: API, PHP

Republished CSTL

I have just republished the article and samples about CSTL (Client Side Tag Libs), which brings TagLibs to JavaScript in an extensible object oriented model. The original articles are well 1 1/2 year old but since everyone seems to talk about AJAX these days, I just want to show, that I had my 50cent to distribute to that subject a long time ago. Besides the links were not working in quite a while. full article download fi...

Categories: Framework, Frontend

Matching IP to country

I have again found a nice article about how to match IPs to countries over at builder.com. It uses PHP::Pear's Net_GeoIP class for the querying. But what really interest me is the data behind it. Luckily MaxMind does provide this data in various flavors. There is a free CSV export at the beginning of every month, which can be downloaded on country level and on city level. However there are also 2 APIs for PHP. For once there is a pure PHP implementation and also a PHP extension as well. I am definately going to try these o...

Categories: API, PHP

Creating MS Office documents using PHP

I have recently discovered an article on how to generate MS Office Documents using PHP. Basically this article does not contain anything new, demonstrating how to utilize the COM API to construct Word and Powerpoint and how Excel can be created from an HTML table. While this article will not enable you to approach the issue in an OS independent way (you will in fact need a windows server to create Word and Powerpoint documents) it still assembles the concepts for all 3 major MS Office products, containing easy to understand code snippe...

Categories: API, PHP

24 ways to impress your friends

24 ways owns a collection of 24 very nice articles about bleeding edge JavaScript and CSS hacks to make things look good and work well. Definately worth a look or two if you are in the web busine...

Categories: Frontend, PHP