My last article on singletons got a few comments on blogs and in email including how it could be improved (thanks Michael) and a few questions. I also omitted the code showing how the singletons were created and called (now added).
So here's the new improved code!
Singletons are perhaps one of the most simple Design Patterns. For those who don't know sigletons are a class that can only have one instance. They can be thought of as a glorified global variable - but are a lot more useful.
Most ColdFusion classes, or rather instances of CF components, can be turned in a singleton by placing the following code in your Application.cfm:
or OnApplicationStart method of your Application.cfc:
I a huge fan of of microformats (or µF), if you're not familiar with them take a look at www.microformats.org and the entry at Wikipedia.
Basically it's a way of marking up HTML to give it more more meaning, think of it as the semantic web (with a small s) that is available now.
hCard is a HTML representation of vCard and while no browers currently support it natively, the next versions of Firefox and IE will support it. There are also plugins currently available for Firefox (Operator and Tails ) and Safari (various bookmarklets) and IE (various favlets).
Consider the following code that implements a simple login.
One of the issues with this is that the password is stored in the database as plain text. Anything with access to the database (including your ColdFusion application) could possibly be used to get a list of all users and their passwords.
There quite a few methods out there for making search engine and user friendly URLs in ColdFusion eg Spike's Friendly URL servlet or one of the many Apache and IIS URL rewiters.
These are great if your hosting provider has installed them or if you have your own dedicated server. So what do you do if this is not the case or you want to support friendly URLs in a web server agnostic way?
