In this mini howto I would like to show how to add a required captcha field in the login form, after a defined number of unsuccessfull attempts.
To do this, I will use the blog demo that you have in default Yii download package (path/to/yii/demos/blog).
Let's say our table 'mug' has a column named 'color' of the type ENUM('red','green','blue').
We want to replace the textfield for the attribute color in the create and update forms of a 'mug' with a Radio Button List, which has the enum values as options.
This is a rewrite of c@cba in the wiki article of enumDropdownListThe main code was contributed by zaccaria in the forum (see this post).
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).