Archive for 29 May 2011

Usability guidelines for entering credit card numbers on a payment page

As more people with very little computer experience start shopping online, usability on an online retailer’s checkout page is becoming even more important. One common problem that impacts the user experience is a very rigid credit card input that does not permit users to enter spaces or hyphens. Consider the following two ways to enter [...]

Why Yoda conditions are bad and usage of Java’s ‘final’ keyword is good

I came across some code a while back that made me pause for a moment as I figured out its meaning. This code used something known as a Yoda condition, also sometimes referred to as Yoda notation. In a conditional block, the operands on an operator are reversed, so that the constant expression is listed [...]

Apache Wicket: Group a set of CheckBox inputs using an enum

UPDATE: a few days after posting this, I realized that there is a CheckGroup wicket class that will group checkboxes together. I’ll write a new article to show how to integrate an enumerated checkbox group with the CheckGroup class. — When presenting a list of radio buttons to a user in a form, it’s a [...]