A simple and effective way to keep track what your users are doing within your application is to log their activities related to database modifications. You can log whenever a record was inserted, changed or deleted, and also when and by which user this was done. For a CActiveRecord Model you could use a behavior for this purpose. This way you will be able to add log functionality to ActiveRecords very easily.
By default, the decimal separator in php (also in mysql) is a dot (.).
So when we work with floats in Yii (in calculations, validation, sql statements etc.), the decimal separator has to be a dot.
If we want to use for example a comma (,) as the decimal separator, that is if we want to display numbers and enable users to enter numbers with a comma before the decimals, we have to...
Installing WAMP on XP was pretty easy; W7 is not so trivial. It's not difficult once you know, but it took me best part of a day to figure out and required gleaning various bits of information from around the web; this tutorial brings it all together in one place to (hopefully) make other peoples lives that bit easier. It does assume that you are reasonably happy configuring Apache, PHP, and MySQL and mainly deals with the W7 quirks.
There are several methods and techniques that come handy in the case you need to call an external resource periodically or if you are waiting for a server push, but I present here an easy and straightforward one using HTML5's Server-Sent Events (SSE).